Transmission Options

[RolesvilleMarina]

I have a 1999 T444E currently has an AT545

I'm looking at my build sheet and it says I have a #2 Bellhousing

so An MT643 should bolt right up I believe yes?

If not, what transmission options are there to choose from ?

 

[cadillackid]

this has been discussed... your T444E currently has an SAE2 bell adapted down to an SAE3 for your AT545..


the BIG ISSUE with the 444E as member Kubla has mentioned in a few threads, is finding the Spacer plate you need that increases the converter offset for the MT643. not that many 444E's were made with 643s so that plate is difficult to come across.



for a 1999 model 444E, an allison 2000 series upgrade is more viable, though not for the faint of heart if you are afraid of electronics.. 2000 series can be found used along with their computers and wiring harnesses.. a 2000 series is a direct bolt up to the SAE3 adapter that your 545 uses. electronics are required and best scenerio is some ECM programming to set it all up and make things work nicely together..
-Christopher

 

[RolesvilleMarina]

this has been discussed... your T444E currently has an SAE2 bell adapted down to an SAE3 for your AT545..


the BIG ISSUE with the 444E as member Kubla has mentioned in a few threads, is finding the Spacer plate you need that increases the converter offset for the MT643. not that many 444E's were made with 643s so that plate is difficult to come across.



for a 1999 model 444E, an allison 2000 series upgrade is more viable, though not for the faint of heart if you are afraid of electronics.. 2000 series can be found used along with their computers and wiring harnesses.. a 2000 series is a direct bolt up to the SAE3 adapter that your 545 uses. electronics are required and best scenerio is some ECM programming to set it all up and make things work nicely together..
-Christopher

Correct, it was discussed to some extent. But then realized I was in a ford forum vs the IH forum so I figured maybe that might help

also didn't know at the time exactly what bellhousing I had until I saw in the build sheet.

I can't do the programming, and unsure who I could pay to do it if I tried a 2000 swap.. the mechanical part yes I can do that.

My question here was what else was or could be bolted to these motors? The T444E was used in trucks as well (a friend has one in a bucket truck, but I am unsure his trans )

I was just wondering what options where available from factory or was it ONLY the At545?

 

[cadillackid]

factory on the 444E that I know of were a spicer 5 speed stick, allison MT643, Allison MD3060, and allison 2000 series.. not sure if a 1000 was offered or not but its fitment and electronics are the same as a 2000 so its equal.



the 444E was considered the "budget" diesel compared to the DT466 / DT466E, so often it was paired with the AT545. the MT643 was a fairly expensive upgrade from what ive read. for a school route bus an MT643 didnt make much sense as an upgrade.. the spend most of their time in town where lockup isnt a big benefit..



many of the 4700 trucks which share a simlar chassis were manual shift that I have seen with 444E's. some did exist with MT643s..



the parts do exist for such installations.. they are just tougher to find, and seem to be expensive when they are found..



the AT545 and MT643 were discontinued in 2003, another bit of info from some of the old posts in school bus forums and from acquaintences who are fleet directors say that once the 2000 series came out, the price was comparable to the MT643.. why not install lockup and an extra gear for the same price.. that occured in year 2000.. so that limited the number of 444E units with 643s even further...



im not saying dont install a 643, all im saying is weigh the costs involved in sourcing parts for the gain you get vs sourcing parts for an allison 2000..


-Christopher

 

[RolesvilleMarina]

factory on the 444E that I know of were a spicer 5 speed stick, allison MT643, Allison MD3060, and allison 2000 series.. not sure if a 1000 was offered or not but its fitment and electronics are the same as a 2000 so its equal.



the 444E was considered the "budget" diesel compared to the DT466 / DT466E, so often it was paired with the AT545. the MT643 was a fairly expensive upgrade from what ive read. for a school route bus an MT643 didnt make much sense as an upgrade.. the spend most of their time in town where lockup isnt a big benefit..



many of the 4700 trucks which share a simlar chassis were manual shift that I have seen with 444E's. some did exist with MT643s..



the parts do exist for such installations.. they are just tougher to find, and seem to be expensive when they are found..



the AT545 and MT643 were discontinued in 2003, another bit of info from some of the old posts in school bus forums and from acquaintences who are fleet directors say that once the 2000 series came out, the price was comparable to the MT643.. why not install lockup and an extra gear for the same price.. that occured in year 2000.. so that limited the number of 444E units with 643s even further...



im not saying dont install a 643, all im saying is weigh the costs involved in sourcing parts for the gain you get vs sourcing parts for an allison 2000..


-Christopher

Thanks

I can't install a 2000 so I will just figure this one out on my own

appreciate the info

 

[RolesvilleMarina]

So I have read EVERY thread on this forum concerning my questions about the T444E coupled to an AT545, gearing, and swapping transmissions. I'm not joking, EVERY thread in this sub category.

Many of the posts this combo is in a LONG bus, although some are in shorter buses like mine.

My bus is a 1998 Thomas Vista 3600 short bus
4.78 Rear end with AT545
Its currently mostly empty at the moment as well
tires are 255-70-22.5


I have a couple of observations, and an apology to Christopher for prob coming across a bit angry/rude.

The first thing I notice is the conflicting information in the posts concerning tire sizes, rear end gear, sustained speed (flat ground) and RPMS. I have also used two gearing calculators to "confirm" what I have. Throughout the posting spectrum people claim different top speeds and yet have the same tire sizes and gearing I have and yet in larger buses?

I had my motor "unlocked" at the IH dealer and my cruise also unlocked. The first test drive home I found that my max speed was now around 57 mph, flat ground, 2600rpm and that was all she had floored.

Yet in my first post (accidentally in ford category) a member claims the same drivetrain and does 65MPH on flat ground (Johnny Mullet?)

Another Says he has a 6.18 rear end and can do 55mph, governed still he says, but only at 2200ish RPM (Patrick Baptist?)

EastCoastCB says he has the same combo but a 3.42 in the rear end and says he gets 65MPH at 1700 RPM??

Other posters say that they get sustained speeds with larger buses with no issues with lower rear ends

then there are many that say that this combo is a turd, cannot be upgraded, and that diddling the rear end taller will make it never climb even the smallest of hills.

So I am now unsure which is the truth eh? Some claim it works fine, others say it does not.


Which also brings me to my apology to Chris, whom suggested to do a 1000 conversion as he did. In fact in a LOT of the threads he tells folks to do this and how happy his with his results. And I read the Red Byrd Transformation in full, multiple times. But there is a major problem with this conversion he fails consistently to address.

1. in the post he does mention he has been "messing with computers since they came out" and is Highly skilled in programming. And thats all good, but most of us are not even CLOSE to his skills. I know computer people, and mechanics with electronic skills and scanners... all I showed the thread were pretty much like WTF (but also impressed as ****)

2. At about page 5 in the Red Byrd transformation is where 99% of us realize this swap is a fools errand WITHOUT his skills... I mean FFS at one point around the page 20 mark he shows a photo of no less than THREE LAPTOPS hooked up as he diddle with the program. Many of us struggle to simply post here

3. This is an issue. Without these critical skills and years of trial and error he has this swap is about worthless for the layman. I reached out and can find NO ONE who is even remotely interested in even attempting this kind of programming. Regardless of how much money I have to throw at it.

4. Which means that EVEN IF I could talk chris into doing this swap for me for a ludicrous amount of money I am now left with a hacked up system no one else down the road would understand, nor touch in ANY Shop if I ever broke down. (I know it would be done right, but "custom customer wiring" is usually gonna get you a "NO" at any service shop.

So Chris I am indeed sorry if I sounded like an ass earlier... I truly am. You are indeed a nice guy, your posts are helpful, and you are a guru.

However your swap is just not something for the lay person and with no aftermarket support on a road trip in another state all alone you'd prob have to abandon the bus or put an AT545 back in it :-(


I also learned that to put an MT643 in requires some adapter that is "unobtainable" but I will keep looking

So for now what I have learned after reading 100+ posts on the AT545 my plan so far is thus

1. Keep the AT545 as it is new
2. Install the trans cooler and temp sensor
3. Flush and refill with the improved "better" fluid as I read in another random at545 post
4. Re-gear the rear end. I am thinking 4.11, but not sure yet

Again the big issue for me with the re-gearing is choosing the correct one as posters claim different MPH and RPM yet the poster's drivetrain is same as mine, and some have larger heavier buses claiming higher speed and lower rpm? I am sure they are not lying, but even when I type in the different gear ratios to the calculator the results do not come close to the numbers I see claimed

I think that was the most surprising was the amount of posts that claim higher and better numbers, and an equal number of posts saying basically bullshit and it won't work if you go taller for a little more speed (flat) and a little bit less scream in the revs



thoughts?

Edit: I should also point out in my apology to Chris (and maybe others) that I didn't mean to come off as an ass... unrelated to this post our home of 20 years just burnt up (not down, but BAD... kitchen wiring they say) and we are dealing with that... it happened in between me posting initially, and the replies..

so sorry lads

 

[cadillackid]

OK im gonna jump in here... m,y. thread about RedByrd is as much me learning as it is building a killer drivetrain...



Yes what I did was / is custom.. an allison 6 speed 1000 / 2000 was never availabe with a 444E.. the 5 speed was..



I wanted a setup that operates BETTER THAN FACTORY setups with the 2000 do.. I drove several busses and didnt like the results i got with cruise control and intuitive shifting.. so I Built my own to do so.. and it works..



I wanted BRAND NEW PARTS.. as I drive my bus everywhere,, the grocery store, the coffee shop or a 4000 mile road trip...



Next on the list would be that to buy used parts and do a 5 speed swap into a bus IS NOT NEAR AS INTENSE as what I got.. and will be MUCH BETTER THAN a 545..



yes there will be some programming navistar must do.. which can be done by any dealer.. they dont need my special unlocked servicemaxx to do it.. my exercise in making my speedometer work with circuits and wires was a stop Gap till I learned to crack-the-code to the computers in such a way I could modify the trans type parameter from AT to MD.. I ditched all those circuits once i did so..



for you to do an allison swap by obtaining a 2000 series with its harnesses and TCM from a school bus is much less intensive.. and skills YOU CAN DO.. that will give you a 5 speed.. with a 0.74 overdrive gear... yes there is some wiring to hook it up. but you wont need 3 laptops.. im a little 145 lb dude and I hiked those heavy transmissions around and got them bolted up in the bus... no special lifts or presses or anything more than tools that can be had ot the neighborhood harbor freight..



what you will end up with is still custom.. the navistar dealer will pull up your bus by VIN and it will still show AT545.. I cant change that.. but any trans swap is never going to show up correctly in a dealer computer.. however you would have a combo that was sold by the factory and therefore more serviceable...



any and all Updates or upgrades to these vehicles are custom and not going to be easily accepted by a dealer... they just wont..



remember I wanted better than factory... most people dont need or particularly want what I built.. my busses arent my home, nor a critical portion of my life.. they are fun.. they are my Laboratories to build custom cool things out of ...



as for speeds and gears.. I can tell you what my gears, tires, and speeds if it matters..



you see a lot of variance in peoples answers with AT545s because AT545 converters are almost never running 1:1. they are either spinning faster or slower than the input shaft of the trans.. so asking someone what their 55 MPH RPM is with an AT545 can mean a variance of 700 or more RPM. because does that pewrson read their gaunge with their foot buried or foot off.. or just barely giving it power..



people with lockup transmissions may have different size tires.. a bus with a 6.18 rear and 11R22.5 tires is going to be faster than a bus with a 5.54 rear and 220/70R19.5 tires.. when comparing rear gears you need to know their tires and compare like to like...



my red bus in 4th gear (no ODwith lockup on ) tops out about 71-72 at 2600 RPM it has 3.54 gears and 220/70R19.5 tires


my DEV bus which is no OD (lockup) tops out about 68 at 2800 RPM with a 4.78 rear gear and 11R22.5 tires..



My Superior(AT540. in 4th no lock) has 4.78 Gears and 11R22.5 tires.. when I run it at 68 my tach may read 3200 RPM if I have it floored or drops back to 2200 if I have my foot off the pedal.. so you can see wide variance even though my going the same speed because of the converter slip.. how do I tell someone what my RPM is and make it believable? RPM calc is the only way..



-Christopher

 

[Booyah45828]

Sorry to hear about your house. Stress like that will make an ass out of anybody. It certainly does to me. Apologizing about it, though, says more about you as a person.

Yup, Chris is more intelligent/ambitious then 99% out there. His 1000 swap is something very few could/would accomplish. I feel he's too humble to admit that sometimes. Most shops/mechanics that could do this won't, simply because they have better/more financially appealing things to do.

And you're correct about the break downs. God forbid it happen but you do have to examine the what if's. Many places won't even look at a school bus, let alone something completely custom made. You're likely on your own if it comes to repair work on something like that.

Speed to rpm is simple. Input the rear gear, input the final drive, input the tire size, input either speed or rpm, and receive your answer of speed or rpm.

My bus will do 70 wide open on flat ground. That's 3300 rpm, 10r22.5 tires, at545, 5.57 rear axle.

If the info for the other guys doesn't compute out, you likely have the info input wrong. I don't think any of the aforementioned (CadillacKid, Johnny mullet, PatrickBaptist, EastCoastCwould lie to you about their speed/rpm, they have nothing to gain by doing so.

I get why people want to immediately swap the 545 at purchase, I've even recommended it to a few to put their mind at ease, but my normal advice is to run it and see how it does, and that's what I recommend here.

So regarding your plan
1. Sounds good.
2. What's your current operating temps? You have no idea if another cooler is needed if you don't know what your temp is. The only thing more cooling might do is empty your wallet.
3. Another wallet drain if it's not needed. What's your current fluid condition? If it's good, leave it. The synthetic stuff is better, but it's not going to show a significant improvement if your current fluid is good.
4. Re-gear it to something that hits around your rated rpm(2200) for your engine at your cruise speed(55,65,70,etc.). This should give you enough giddy up to accelerate from a stop, yet won't lug the engine, or run the transmission at too low of an rpm.

*be realistic about your cruise speed. Setting it to go 80 like some fantasize about will make it undesirable. Most lack the HP/brakes and tires to get there anyways. I'd likely make it 60-65 area. If you want to go 80, you need more gears, there's no better way around it.

 

[RolesvilleMarina]

Thanks Chris

1. I hope you accept my apology

2. So I am confused now... I am aware you wanted new and etc...
but you are saying I can go with a 2000 transmission and related parts and can put this in without massive programming from someone like you? I do confess I got confused at some point between the 1000 and 2000 but thought both would require massive 3 laptop programming.

3. Installing the transmission itself is not an issue for me, nor fabricating any mounts or anything like that. I am also a small dude with no strength but I have a full shop and am not afraid of this part. However any computer stuff stops me cold. I have dyscalculia so I am just out... I have to pay someone, but $ I have.

4. As far as being "custom" and dealerships/shops If I can plug and play a 2000 into the bus I guess it won't be as much a problem as the custom setup I was referring to? If a Navistar dealer can connect to both the Trans and the Engine then it won't be a 3 laptop fiasco?

5. As for the variances in the numbers I am getting are all over the places...and this is only in threads with AT545 transmissions, and no lockup transmission (although I read a lot of those too. I read about all 33 pages in this sub cat)

the 3 I referenced in particular where in my ford thread. So the diff in a 10 vs 11 inch tire is over 10+mph? as again the speed calculators I played with none of the claims match up? One calculator I found here includes transmission type and gives you a graph of shift points and speed. Nowhere do I get anything close to 70mph


Ideally I would like to do your 2000 swap, but if it is a 3 laptop endeavor its impossible... If I can throw in a 2000, fab it all in, have it towed to IH dealer and programmed I would be in for that route

or keep the AT545 and re-gear

We also have no plans to live in our bus, and money is not an issue. I wanted the Vista bus, I am prepared to spend $ adjusting the drive train to get what I want (60mph, a more comfortable rev...flat ground...ability to at least get up a hill)

I just want to make the correct choice

 

[RolesvilleMarina]

Thanks Booyah

1. Unsure what my temps are... no gauge (yet) but I am aware I have the tiny split radiator..I live in NC and its Hot as balls in the summer... I have not had the bus long enough to drive it on any kind of extended trips.. I drove it home from purchase. After I got it registered I drove it to have it unlocked, and then drove it home and discovered max was 57 at 2600 with 4.78. Downhill I got a few more MPH so I know its no longer a governor issue thanks to the unlocking.

I cannot rev past 2600 and according to Chris this is from factory, and a good thing not to exceed.

What engine do you have you can achieve faster than me doing 3300 rpm, 10r22.5 tires, at545, 5.57 rear axle. you are achieving more revs than I do, but your gears are much higher than my 4.78 ??

2. My trans is new (jasper rebuild) and although I do not know the exact mileage it looks brand new, and the fluid as well. The whole bus has new parts all over it (and no rust) motor looks new and clean as **** as well... dash says 280K but we all know dashes get changed. VA county school district told me to basically sod off when i called and asked if I could get records with the buses route #... downright rude actually

3. I know the fellows I referenced are not lying and am no way implying it... but they are giving me numbers I can't get in the RPM calculator and speeds that exceed what I get with larger buses and higher gears? more than 700 or so differences...so is confusing

4. Down the road you can get away with some custom stuff, and i can fix 90% of my own issues, unless 3 laptops come into play :biggrin:

5. Cruise speed desired is a comfortable 60 mph at a lower rev (the threads seem to indicate the T444E likes 22-2300) with enough pedal for a little extra when and if needed...would like to be able to hit the minor hills (not mountains) without slowing to 15mph and not to destroy the motor by lugging it, or overheating the At545

thanks

 

[RolesvilleMarina]

I typed in Booyahs numbers and unless I got the tire size wrong (I dunno what 10r is when it is asking for a 3 digit number) so I used my tire size of 255-70-22.5

it says the max speed on a 1%grade is 61 mph ?

Using this SPEED CALCULATOR

 

[Booyah45828]

Get a gauge. They're cheap enough and invaluable to preventing transmission overheating.

2600 rpm is governed speed. You can't exceed this unless you're going downhill. Running near this at highway speeds is just wearing out the engine and burning fuel.

I have a 6.9 idi. Peak power is 3300, governed speed is 3500. Most diesels aren't this high. I try not to run it that high because it does nothing but create heat and waste fuel.

What you want should be achievable. What rear axle do you have? Using that, we can look up available ratios and then go from there on what you want to select. Using 60-65 mph, with 255/70R22.5 tires, an at545,and a desired rpm of around 2200, You'll want a ratio of about 3.73:1 in the rear axle. But you'll have to see what options are available to you based off of the axle model.

Just for giggles, if you would change your tire size to a 10r22.5, you'll drop 200 rpm off your cruise speed. A more common 11r22.5 would make it even bigger. So tires do play a difference.

 

[Booyah45828]

I typed in Booyahs numbers and unless I got the tire size wrong (I dunno what 10r is when it is asking for a 3 digit number) so I used my tire size of 255-70-22.5

it says the max speed on a 1%grade is 61 mph ?

Using this SPEED CALCULATOR

Find a calculator that uses diameter, like this https://spicerparts.com/calculators/engine-rpm-calculator

10r22.5 has a diameter of 40.5 inches

Your tire has a 36.56" diameter

I think we found your confusion.

 

[brokedown-SKO]

Heya,

I had a 5 window Vista with the T444E and AT545 (actualy AT542 which is an AT545 with a shallow fluid pan) and 4.78:1 axle so I think i can give you some helpful info from my experience.

It sounds like your AT545 is slipping more than mine did. I had the 19.5 wheels but I was able to cruise around 58mph on flat ground with a couple hundred RPM to go. I could touch 65 or so if I wanted but i didn't like my engine screaming. Have you checked your fluid level? More slip means more heat, so I second the recommendation for getting a temp sensor asap.

If you swapped the axle chunk to a lower ratio, you could significantly improve your speeds. 4.44:1 is common as is 4.11:1. They go lower as well but I'd be concerned that it will increase slip if your transmission is worn.

Swapping the transmission is not trivial, as you've found the bellhousing adapter for a MT643 may be unobtainable. However, we do have ECCB with a tight AT545 and super low gearing to show that it is possible for them to work well together. i've ridden in his bus and that gearing is amazing! You may find that freshening up your AT545 along with a lower rear axle ratio is a cost effective way to go. Unlike a complex swap to a computerized transmission, it's something any transmission shop has likely done a bunch of times already and can give you a fair price.

 

[RolesvilleMarina]

Thanks Booyah

1. Gauge is on the list whether I keep the At545 or not. Like Chris I like the dash gadgets and input. I plan to have a friend help me with a tablet mounted bluetooth plug to get digital dash readouts (I'm kinda subbing that out lol)

2. Yes my confusion... so where and how do I find out 10 R or 11R with the 3 #'s stamped on the tire that none of say 11 or 10? I see your last post just now and I have smaller than 10 I guessing?
Also there is not a lot of room and I do not think i can stuff anything larger under there.. I am going to have to look into that, but I have air ride so I dunno what until I look if I can raise it... currently pouring outside so can't check today

3. I have the line-set so it says the axle is
" Axle, Rear, Single
{International N-175} Single Reduction, 17,500-lb capacity with 190 wheel ends "

Transmission - AT-545 includes TC-290 Torque Converter and Transmission oil filter, and less retarder and PTO (of course, FML as would love to have both:biggrin

Gear ratio : 4.78



again its raining here so a good day for research
thanks very much

dave

 

[RolesvilleMarina]

Heya,

I had a 5 window Vista with the T444E and AT545 (actualy AT542 which is an AT545 with a shallow fluid pan) and 4.78:1 axle so I think i can give you some helpful info from my experience.

It sounds like your AT545 is slipping more than mine did. I had the 19.5 wheels but I was able to cruise around 58mph on flat ground with a couple hundred RPM to go. I could touch 65 or so if I wanted but i didn't like my engine screaming. Have you checked your fluid level? More slip means more heat, so I second the recommendation for getting a temp sensor asap.

If you swapped the axle chunk to a lower ratio, you could significantly improve your speeds. 4.44:1 is common as is 4.11:1. They go lower as well but I'd be concerned that it will increase slip if your transmission is worn.

Swapping the transmission is not trivial, as you've found the bellhousing adapter for a MT643 may be unobtainable. However, we do have ECCB with a tight AT545 and super low gearing to show that it is possible for them to work well together. i've ridden in his bus and that gearing is amazing! You may find that freshening up your AT545 along with a lower rear axle ratio is a cost effective way to go. Unlike a complex swap to a computerized transmission, it's something any transmission shop has likely done a bunch of times already and can give you a fair price.

well hello :Thanx:
i read extensively on your travels with the Vista after we bought ours, and about everything you posted about it. Almost feel i know ya lol

As I confessed I only have been able to drive the bus twice... I checked the fluid color on purchase but also confess that I have not checked it according to proper procedure and level. This is a failure on my part, and also in knowing that changing one or the other is inevitable I haven't really gotten deep into my actual trans as of yet... nor put it through any major miles (took awhile to get vermont plate) I just drove home the purchase and it was stuck at 55.... after unlock I drove on highway and got 57 ish

I am aware of the slip, but hadn't considered it as you have pointed out. I am going on the fact that the fluid and the trans itself look about near new, and I have never driven a 545 trans ever to compare with the feel

so I played with calculators and read forums lol

as you put it " I had the 19.5 wheels but I was able to cruise around 58mph on flat ground with a couple hundred RPM to go. I could touch 65 or so if I wanted but i didn't like my engine screaming. "

this is what I wish... We are towing a small sailboat, we are still way under weight even with it, and no wish to go "fast" even uphill... as a mechanic i want comfortable and no scream :biggrin:

its a road trip vehicle... as we sail we will mostly be on the flat ground. We may do a mountain one day, but as many proved it can be done, and since it won't be often and then back to flat and the sea I think we would be ok

Ideally I would like to honestly keep the 545, re gear and go smooth
545's are a dime a dozen, I can swap one in a parking lot if I had too... this is a big plus to me the simplicity

i've read enough about it to care for it properly at this point and keep it alive

thanks still raining here

Dave

 

[RolesvilleMarina]

Whats the proper procedure to test level of the At545 transmission fluid?

hot, level and in nuetral running is my first guess


this whole slippage thing... how much is too much I wonder know if I have a bad trans although again it looks new

 

[cadillackid]

regearing is not hard.. regearing will make your transmission run hotter.. a Big cooler is not a huge job and will definitely increase the life of your AT545 even with new gears. im sure i killed both of my 545s (one in each of 2 busses) because I ran those busses all over the place.. many miles mountains, summer heat, winter cold and in between..



back to reg-gearing - I recently regeared my Superior bus.. a moment about that bus.. its a 1978 International Loadtsar with a SV392 gasoline engine and an AT540.. thats the one that can rev to 3300 RPM.. it can actually go up to 3800 if I wanted it to.. its a gasoline engine.. ..


onto regearing.. I took the easy (and more expensive) way to re-gear.. I took my whole carrier unit out of the axle.. (its not hard you dont ven need to take the tires off)... most rockwell,spicer,dana axles have removeable carrier units.. the axles slide out the sides of the wheels.. the driveshaft comes down with a U-joint, and the carrier unbolts as a unit and comes out.. it weighs a few hundred pounds..



I took it to Weller truck parts ,whom looked its numbers up, and gave me options on what could be obtaned for it as far as gears.. I wanted a 5.29 but since it was so old that was no longer available.. they found 4.78 was available for it.. and I had them remanufacture it.. I got it back about a week later, and put it on.. since the gears were new, I installed it, filled it.. drove it 100 miles non-stop. (just the normals of stop N go traffic and freeway.. ).. then i got home.. drained the oil, and changed it..



sure it cost me a bit of $$ to get it that way, however its new parts and has a warranty.. weller truck parts exist in many of the areas I travel...



with a T444E you need to reprogram the speedmoeter on the dash to read correctly.. trhats an easy change with ONE LAPTOP..

-Christopher

 

[cadillackid]

as for converter slippage.. it all depends on the converter installed.. there were several available.. with AT545s the same story circulates.. (mine is tight, but the other guys' is looser). the trans itself isnt likely slipping.. if it is then it wont last very long at all.. and that one is an easier one to spot.. a slipping trans usually results in beng able to completely run away with the RPM.s. meaning when it shifts you stay pegged at the rev limiter and dont gain much speed..



converter slip varies with the converter model used.. sometimes the schools that had these busses swapped transmissions around.. ie they kept a couple on the shelf with torque converters and swapped one in when it died.. chances are they didnt get them rebuilt at the chassis dealer but at a trans shop who rebuilds what they get or sells as remanufactured for "diesel or gas".. there is a test somewhere in the allison book on how to stall test the converters.. id have to look it up to see if any tools are needed.. I think it involved watching the pump output line pressure of the trans while you torque the trans in D with the park brake set.

-Christopher

 

[Booyah45828]

There is an inch vs metric tire sizing. The 3 # method is metric, the 10r method is inch.

You can find converters that go back and forth. Best bet is to look on a tire manufacturer's website and find the overall diameter of the tire size and use that. Most 10r22.5 have an O/A diameter of 40.5 inches. Your 255-70-22.5 has an O/A diameter of 36.56 inches.

In the calculator you linked(it's a pretty cool one btw), put the O/A diameter spec from the tire in place of the wheel diameter, leaving the first 2 options blank. That makes your calculator work accurately.