REDBYRD - Gets a new Rear!

[cadillackid]

After i replaced the allison AT545 in redbyrd to the new allison 1000 6th speed, ive had a need for a shorter rear end gear.. ive mitigated it with running much higher than average shift-points, and watching my EGT puro gauge closely as t onot lug it..



my stock rear end is a 3.54, and im going to a 4.44, the original plan was to go to a 4.10.. but thanks to the great knowledge and help of people on this forum i decided to go shorter with a 4.44


the T444E engine is tuned with upgraded injectors, HPOP, and no EBPV. ive been running the tuner way down on setting 3 or 4 (still LOTS of power).. simply to keep my EGT down on inclines...



my normal cruising speed is 65, in 6th gear i was taching at 1500-1550, 70 MPH was 1650 max. thats just way too low..


my 5th gear was 1780-1800 at 65 and 1880-1900 at 70, still low for 70 in 5th gear..


the new gears should raise those RPMs in the 450-550 range which puts me in a better position for my 65 MPH cruise speed wit hthe T444E.. Ill be able to run the power up another setting so not only with the lower gears and the added power... alas off we embark on this project..


thanks to the FINE folks at Michigan truck parts (located near ann arbor).. I found an S135/S150 rear 3rd member from them.. they are a recycler and like many of us they LOVE and take pride in the older trucks.. nice clean operation they have.. I got a real fair price on a refurb rear end. they go through any takeouts.. look for any gear damage, reset pinion depth and set the lash if needbe, new seals, new pinion washer and nut.. they will change the bearings if worn also.. you get the setup with the marking paste still on the gears so you can see how their setup is.



they loaded me up.. dropped it right in my pickup bed, oiled, wrapped, and pallet..







the road trip from ohio to michigan gave me a chance to also get some work done along the way and try 2 new coffee shops!!





-Christopher

 

[jazty]

Sounds painless so far!
I'll be following this with interest. I'm in the same boat with low RPMs at highway cruising speed.

For my use case I'd like to find one with an air locker, too (if such a thing exists for my axle).

 

[cadillackid]

im attaching the Spicer book i have here imthis thread... im not sure what axle you have.. I know there are some that are made as "suregrip" i think they called it.. im guessing some prob have air locker but maybe not..


View attachment spicer-rear-end-part-numbers.pdf


maybe something in there can help.. then you can search the various used truck places.. or if you want to get a reman you can go throgh weller... there isnt much that weller cant build.. (wont be cheap though)..


looks like a 'D' suffix on a carrier is a diff lock.. doesnt say air so mnot sure how its actuated.. they also make limited slip

 

[turf]

wow, i didnt realize your rpms were so low.

that would give you a theoretical cruising speed @2500 rpms of .....?!?? over a 100mph?

what cruising rpms / speed are you shooting for?

and how fast does it go now? (asking for a friend)

 

[cadillackid]

Next after procurring the parts.. time to go to work!, gotta get the old one out..



so first thing I do is make sure the transmission is in N, chock the wheels and then release the park brake.. (releasing the brake is only necessary if you have hydraulic brakes.. with air brakes the rear wheels are you brake..but still chock the wheels)..


this lets me know my bus isnt going anywhere..



now I look to see if my driveshaft is in phase already... meaning that you want the FIXED ends of the U-joints all in a line.. this bus has a 2 piece driveshaft so I make sure that the Fixed end on the front shaft at the transmission.. lines up wit hthe fixed end at the splined end of the second shaft.. (and of course the rear U joint lines up as it is welded on so that the fixed ends align.. I mark it with a paint pen and put it aside..



drain the fluid. I was amazed in my case how clean the fluid looks.. it was the color of ever so slightly used motor oil... just a shade darker than honey... the S150 holds 3 gallons so use a pan big enough to catch it..





Next you want to get your pinion nut removed. unless your new rear has a yoke already on it... then dont need to ..


pinion nuts are VERY tight... I used a spanner wrench that I could bolt down to 2 positions on the yoke then hold against the frame.. I bolted it down tight..









technically you arent supposed to use an impact on a pinion nut but ive never had any issues doing it to remove one.. you dont want to tighten a pinion nut with impact... my milwaukee 1/2 inch Zinged it right off without a ton of effort.. the spanner wrench tightly against your bus frame or floor or the ground holding the pinion from spinning is Paramount..



now pull the axles, there will be some fluid up in the hib itself that will drain out.. some of it is purposely trapped up there so when you round curves the wheel bearing on the inside doesnt run dry... I pulled the axles out halfway and let them sit... if you dont pull them out far enough, the rear end will get hung up on removal.







getting closer!
-Christopher

 

[cadillackid]

wow, i didnt realize your rpms were so low.

that would give you a theoretical cruising speed @2500 rpms of .....?!?? over a 100mph?

what cruising rpms / speed are you shooting for?

and how fast does it go now? (asking for a friend)

when I did the tranny swap.. someone did a theoretical calculation that said it had a top speed of 114 MPH... (so over the 88 MPH necessary for time travel)


my normal cruising speed is 65... i sometimes run 70 but its ony if im trying to navigate fast city traffic..


so i did run the bus up to 80 because people here seem to want to build 80 MPH busses.. and my EGT light was flickering a lot at 1200F so i didnt keep it there too long.. i couldnt do it in 6th.. it ran the EGT into the red zone too easy.. in 5th I was still around 2000-2100 i think...

 

[cadillackid]

I hit all the bolts with an impact and loosened them all.. the weight distribution on these is typically a bit facing the housing so it wont fall out.. but I left 4 bolts partially in (you want to leave them a decen way in..


put my transmission jack under the junk and using a ratchet strap, tied it down to the plate.. also arranged the stops to keep it from just sliding off..



an S150 is about 250 lbs... a bigger one like a full size bus has is around 350-375 lbs..


ive had this harbor freight jack for 20 years and its given me zero issue.. it just works when i need it to..


I did raise the bus a few inches on a 20 ton bottle jack.. no i didnt use a stand.. in the case here I did it just for a bit of body clearance to pull the rear chunk .. i wasnt working in a crush zone.. he the jack gone down the clearance was still way above what a person needs to be underneath.. I just want a couple inches on the skirt...






it is heavy enough you wont be able to just lift it up into the bed of a pickup.. i use my small engine hoist for that job..



analyzing my old gears.. they are still in REALLY GOOD shape.. very little lash ..amazing for over 200K miles..








-Christopher

 

[cadillackid]

Next i cleaned the housing (including the magnet) with brakleen and wiped it down good.. also cleaned up the gasket mating surface with scotch brite... it really wasnt bad..


time to go out with the old in with the new





using a couple 5 inch long by 1/2 coarse thread bolts with the heads cut off.. I screw them into the housing.. (far enough the bolt threads come through the inside of the housing).. these are my guide bolts..


I purposely chose grade 5 over grade 8. grade 8 bolts are stronger however when over stress they will just snap and not bend.. also i dont want a bolt that is stronger than the housing.. I want the bolt to bend if something goes wrong or im stressing things... then I know something is wrong..


strap the new rear to the jack and go... the cut down 2x4 on a piece of plywood i use for the bigger ones wouldnt work here so I just set a 2x4 under the back part of the carrier.. this lets me keep the tray on the jack straighter...



using Permatex special made for gear-oil, I put a nice bead all the way around the housing, circling each bolt hole... the working time on it is 20 minutes, I like it to be installed 5-10 minutes before slamming the parts together..



using small adjustments to the jack i just guide it in on the pins.. its easy to feel when its moving correctly or if it starts to bind.. you want to go straight in with the S150..





the S150 is light enough you can push it in yourself.. i did have a small 1/4 ton chain hoist with me in case I needed to I couldve set it on the rear bumber and pulled the jack forward.. but wasnt necessary..


I got the obligatory and very satisfying "Ka-Chunk!" sound when it seated.. anyone who has ever worked on transmissions, rear ends, clutches.. knows the sound exactly


-Christopher

 

[ol trunt]

That was FUN! thanks. I'd trust you to work on my bus no doubt! Well planned, well documented and displayed.
Jack

 

[Bus'n it]

Wow, first of all, I am impressed you did this all by yourself. Second, I am impressed you had the motivation to do this job on your own! That's freaking awesome and I applaud you. I know all about the Ka-clunk sound. I can't handle heavy weights anymore and I am not that old!

 

[cadillackid]

Wow, first of all, I am impressed you did this all by yourself. Second, I am impressed you had the motivation to do this job on your own! That's freaking awesome and I applaud you. I know all about the Ka-clunk sound. I can't handle heavy weights anymore and I am not that old!

im a little dude.. (5'9 and 145).. most things i work on are heavier than me... ha! thats prob why I have a garage full of hoists and jacks and bars and BFHs, and hand winches.. etc

 

[cadillackid]

OK back at it!


here we are all bolted up.. I let it sit overnight before adding fluid.. I like the permatex to have a chance to really skin over.. theres plenty of other work to do so you dont need to put fluid in it right away.






I like to put the axles in before the driveshaft is installed.. the yoke rotates real easily ..the axle splineso n your new one may not be perfectly in line so you can feel when you are in.



axles can be a little tricky.. typically the end of the axle rests lower in the tube than the whole it needs to find, soI use a bar that lets me have a little more leverage to raise the far end of the axle and go in.. you'll feel when you engage the splines and it will easily slide in.. pull out the bar and slide it in place.. this should not take any force.. if its not going in all the way you have not found the splines on the other end..



the gasket is likely a multi-use gasket as ive never had one come apart.. but I still put a Thin coat of gear-oil RTV on Both sides anyways...






do this for both sides..


nowq its time to tighten the Pinion yoke nut.. if you just put a socket and a long bar on it then everything wants to spin.. and yes it will try to make your bus roll so BE CAREFUL.. with air brakes the tendency is a lot less, but still take note..


the best way is with a spanner (or a DIY Jig you can make yourself out of some flat bar..



the yoke just slides on.. I coat the splines on the pinion shaft , the inside of the seal, and the inside and outside of the yoke with gear oil...



trick is pinions fit fairly tight in the splines and MUST GO ON STRAIGHT!.
if it doesnt just slide on perfectly easy.. get a piece of 2x4, a plastic hammer and tap it in in the center of the 2x4.. dont try to hammer right on the yoke as you'll always be trying to push it from one side or the other.. it wont go on.. remember straight on..



the best way is to always use a brand new Pinion Yoke nut... for these axles there are 2 styles.. 1 style is a flanged nut, and the other is a nut and washer.. inion nuts have an anti-back-off compound installed on them and are designed to be 1 use..



the S150 uses a 1.75" socket.. these things need to be TIGHT.. you can look em up in the book but generally anywhere from 500-1000 ft lbs is the typical torque...



there is no crush sleeve on these, they use a fixed spacer..



you can read online every reason to use or not use an impact on a pinion nut.. some say it ruins the bearing, others have done it and lived to tell about it.. and yet others like me have done it both ways and had no issues..


the book says dont use an impact.. and I have the 3:1 torque multiplier and bars to actually torque it down to the 600 ft lbs it needs so I did it this way..



if you dont get it tight enough can your pinion yoke come off?



theoretically it could.. however one of the reasons for using a new nut is it likely wouldnt come off all the way.. it would start backing off and youd have a pretty good leak at the seal... that said, the engineers want it super tight for a reason...






now,
PUT OIL IN IT!!
yes before you install the driveshaft, fill it...



for one, you can spin everything (if you have a wheel off the ground) and coat all the gears with oil under zero load..



for two, you wont forget to put oil in it!


for three you can see if you have any leaks


how full?
OK so the book says 3 gallons in an S150... that leaves the level about 3/4" below the fill hole (checked after the jack was removed)..



here is some more debate.. some say filll to manufacturer spec, others say fill it till oil starts to drizzle out the fill hole...



then theres me.. I fill it to just below the fill hole..


I can just barely lower my finger tip below the oil and it gets oil.. no mess down the pumpkin and still full enough that pretty quickly the oil will heat up, expand and be prob over the hole..


there is no oil-pump in a rear diff.. the ring gear actually is designed to be an oil slinger.. picking up lots of oil.. and rotational direction such that the pinion and ring , where meeting are doused..


my wheel was still up so I spun it around a few times..( with air brakes this isnt possible easily unless you pump the air system up and take the brake off.)




install the driveshaft.. Phase it up like mentioned earlier.. with all the fixed ends in align..

(this gave me a great chance to finally get rid of those old muffler clamps!)




take a nice slow roll around the block and make sure nothing leaks or somes apart.. I did a few laps around mty storage place.. then rechecked my fluid level...


test drive - with a used rear gear set you can drive it as normal.. there isa no break-in and no need to change the rear oil shortly after the install as these gears have already run together for ?? miles...



with New gears, fiollow the break-in instructions on the set.. some shops will pre-run a set of gears on a machine for its first run in.. gears are machined "mostly" in the factory.. and then really are finished machining when installed in their carrier....



I took a full-speed test drive.. of course my comoputers complained at me pretty adamantly as I havent yet reprogrammed them... my allison did OK but my cuastom shift schedule to mitigate being way over-tall on gears doesnt work the greatest here..



so my next thing to do is reprogram the computers to make them happy..

your speedometer will be off and will need to be reprogrammed.. either in the ECM or in the case of an older bus (internartional) it has DIP switches to-reset.



-Christopher

 

[cadillackid]

That was FUN! thanks. I'd trust you to work on my bus no doubt! Well planned, well documented and displayed.
Jack

I wanted to chronicle this as there is a LOT of talk on this forum about transmission and gear swaps.. i think alot of people here / read about the buzz words and dont always know what its about or what has to happen when they get a bid from a shop to do it, or want to DIY it..


im all about people learning and DIYing it.. I take a LOT of flack in the HVAC community because I am an avid promoter of DIYing A/C, heat, and ventilation... being a former career HVAC guy.. the "community" thinks I should uphold the field by forcing people away from DIY... im the opposite.. knowledge is power.. the more you learn, then maybe you can DIY it.. or at least be more informed when you choose a shop / contractor to do a job...


I grew up with tools in my hand.. my dad literally had a machine shop in the basement.. drill press, lathe, band saw, table saw, small press, radial saw, bench grinder, torch set, welder..



the shop went with us when we moved to the country and got its own building where he has it now.. my grandfather (gone before i was born).. used to build and make everything.. he worked at International Harvester.. dad worked at GE till he got his OSU degree and got into engineering... this community here is a welcome sight because its people who are Builders and makers.. and those who want to be builders and makers.. thats a big grin for me!




in my age group (mid 50s).. I fear we are some of the last who got giddy waking up on christnas morning and finding a shiny red toolbox of our very own under the tree... (vs todays kids that want a plastic PS5)....

 

[Bus'n it]

Proud of you for tackling this and showing what is needed. I grew up with a dad that was a machinist but at a factory. I inherited his Kennedy tool box with odd ball bits and calipers. Thanks for sharing your "growing" up stories. I too tinker with A/C's and procured many tools to do the job. Installed several residential mini split units that are working strong over ten years.

I look forward to your driving observations once you get everything to talk it out and handshake peace over one another! I am 54. Sounds like you are my age. I can't swap gears due to weight of things despite having a pit. ( I am 162lbs) so I leave that to my wallet and others.

 

[nikitis]

so my next thing to do is reprogram the computers to make them happy..

your speedometer will be off and will need to be reprogrammed.. either in the ECM or in the case of an older bus (internartional) it has DIP switches to-reset.

What I learned regarding the DIP Switches on the gauge cluster in Internationals is if it's set to all 0's, it will use the VPM Settings. Or ECM if 1, 2 box. Mine is currently set to 0's, so if you program it in servicemaxx right, the cluster should read from there. The DIP's are only for Buses without electronics to tell it. At least with the mid 90's international square gauge clusters.

 

[cadillackid]

What I learned regarding the DIP Switches on the gauge cluster in Internationals is if it's set to all 0's, it will use the VPM Settings. Or ECM if 1, 2 box. Mine is currently set to 0's, so if you program it in servicemaxx right, the cluster should read from there. The DIP's are only for Buses without electronics to tell it. At least with the mid 90's international square gauge clusters.

correct.. DIP switches are for those with mecahnical engines but have an electronic speed sender.. (the 88 and older (S-series) used a cable which requires a gear change on the tranny)..



the later panels (with full datalink) dont even have switches...



the earlier panels (has the 230 max temp gauge and full -around oil P (mechanical gauge).. have the switches..

 

[nikitis]

Ah okay so because you swapped to an Allison 1000, it might as well be a mechanical setup and thus you require the DIP Switches.

Is REDBYRD a 3Box?

 

[cadillackid]

Ah okay so because you swapped to an Allison 1000, it might as well be a mechanical setup and thus you require the DIP Switches.

Is REDBYRD a 3Box?

sorry my DEV bus is all mechanical and uses the DIP switches..


my Redbyrd is a single box(T444E) and its allison 1000 uses the J1939 datalink to talk to the ECM..


remember I have several busses

 

[cadillackid]

lets program the computer!!


im re-posting the calculations from another thread here.. anyone who wants to change their gears will likely need the number of tone ring pulses per mile.. (for the dip switches or for the engine computer)..


I marked the tires and drove along side a tape measure... 3 marks on each tire at the bottom of the tread.. 3 full treads touch the ground at all times.. so i can know im pretty exact..



using 3 marks I ended up being amazingly consistent on my readings...


Start 1 ft 1.5
2. 9 ft 3.5 - 8 ft 2" - 98"

3. 17 ft 5.5 - 8 ft 2" - 98"

4. 25 ft 7.5 - 8 ft 2" - 98"

5. 33 ft 9.25 - 8 ft 1.75" - 97.75"

6. 41 ft 11.5 - 8 ft 1.75" - 97.75"

7. 50 ft 1.5 - 8 ft 2" - 98"

8. 58 ft 3.5 - 8 ft 2" - 98"

9. 66 ft 6 - 8 ft 2.5" - 98.5" - is this one an omen?
10. 74 ft 7.5 - 8 ft 1.5" - 97.5"

11.. 82 ft 9.5 - 8 ft 2" - 98"



so add it all up and divide by 10 (I did 10 revs.. per Magnakansas suggestion).



total of readings. 979.5 / 10 = 97.95" rolling circumference.


divide that by pi to get diameter.


97.95 / 3.14159 = 31.178", (this is my tire height).. def not the 31.5" the books list for a 225/70R19.5.


** OR ** I have worn 2" of an inch off my tires in ther 5 years they have been on.. remember tire height is a measurement of distance from the bottom to the top.. so if think about it you wear .2" off the "bottom" its also going to be gone off the "top" if measuring the height of a tire for a calculator..

tire height isnt what we need.. the 97.95 that we rolled off is the number we need.



the number of inches in a mile (using 5280 feet X 12) = 63360.


now we need to get the number of times our tire spins per mile..


63360 divided by 97.95 = 646.86 revs per mile


now we need the number of times the driveshaft spins per mile.

so multiply the wheel revs times your rear gear ratio.
in my case with the new gears. 646.86 X 4.44 = 2872.058


now we need the number of electronic pulses per mile.. many allisons are 16 pulses per driveshaft rewv.. others are 40..


mine is 40 pulses per driveshaft rev.
2872.058 X 40 = 114882.45.


thats the numbere you program into your computer..

 

[cadillackid]

I chose to use Servicemaxx to do the programming...


if you have an Orion tuner from PowerHungry, one of its great features is you can use it to change parameters as well..


ServiceMaxx and orion are just for the international chassis busses.. if you have a bluebird, a freightliner, thomas, ford, etc you'll need to source a different tool...



I program both the Pulses per mile and also my new gear ratio into the computer.. this makes the speedometer work correctly. on international, the gear ratio and tire revs per mile also helps the cooputer to determine how aggressive to make the cruise control.. (at least it seems to..)..








-Christopher