AT545 to MT643 DT466E swap - Page 4

cadillackid · 03-28-2021, 06:21 PM

definitely not much grab from that starter.. wonder if someone has it shimmed way out? the pattern on mine had at least 1/2 the teeth getting hit.. I painted my ring gear with ring and pinion marking paste when I had my DEV bus apart just to see how far the starter engaged.. I cranked the engine a short distance with the fuel turned off to watch it. I was just curious more than anything..

JT20 · 03-28-2021, 06:41 PM

Quote:

Originally Posted by cadillackid

definitely not much grab from that starter.. wonder if someone has it shimmed way out? the pattern on mine had at least 1/2 the teeth getting hit.. I painted my ring gear with ring and pinion marking paste when I had my DEV bus apart just to see how far the starter engaged.. I cranked the engine a short distance with the fuel turned off to watch it. I was just curious more than anything..

Well when I took it off, the starter was matted flush against the flywheel housing. So I’m not sure?

I would imagine because of the age of the bus it’s probably been replaced before, but not sure.

Simplicity · 03-28-2021, 08:47 PM

Quote:

Originally Posted by JT20

So guys I've got a question.

Since I'm at a point that I could remove the flywheel housing, would it be worth it to pull it and check the rear cam seal?

my understanding there is one behind that housing.

I would hate to leave it if its a possibility that it could be bad. are they a common thing to go bad or leak?

I don't know how much work it is to remove, inspect, replace (necessary or just because you're there) the cam seal, yet it sure seems like this is the time to do it.

If it's okay, well, you spent some time. If it's not, you saved a bunch of time, money, frustration, etc. by not having to tear it all apart, fix it and put it back together.

JT20 · 03-29-2021, 07:23 PM

Well I called international and they wanted 1000 bucks for the flywheel. I lucked out and found a guy selling one that he bought in a bus auction with other parts. So I got it for 300.

I did have to drive 3.5 hours to pick it up but saved me a ton vs getting one from a dealer. It looks new, I don’t believe it’s been used.

Also got my flywheel bolts in grade 10.9 and went ahead and got a cam seal. I guess since I got it apart I’ll put one in it. Since the weather is going to be good tomorrow, I’m going to try and get it done tomorrow, or at least the transmission in.

Simplicity · 03-29-2021, 11:08 PM

Looks great!

Hope the cam seal isn't much effort.

Was that 3.5 hours total or one way??

JT20 · 03-30-2021, 06:50 AM

Quote:

Originally Posted by Simplicity

Looks great!

Hope the cam seal isn't much effort.

Was that 3.5 hours total or one way??

Yeah it was up in Beckley West Virginia, 3.5 hours one way.

JT20 · 03-30-2021, 10:02 PM

ITS IN!!!

Haven’t put the nuts on the TC, and the bolts from the transmission to the engine block are in just snugged up, I’ll have to pull them back OY and put lock tight on, I honestly don’t know those torque specs on either one.

Getting the cam seal in wasn’t too bad, taking the flywheel housing off was heavy but that was expected.

On my bus between how it was parked and being on gravel/ mud it was tuff, the 800lb transmission jack from Harbor freight really wasn’t sturdy and didn’t want to roll very good on plywood, it was pretty sketchy. Had to use ratchet straps quite a bit.

Had to jack one side of the bus up pretty high to get it underneath, then lower it but leave it high enough on Jack’s stands so I could get it up and over the center support, had to drop one tie rod end to get it to clear.

But at least it’s in there, it was just me and my wife, I think we did alright.

Simplicity · 03-30-2021, 10:14 PM

Right on!

Good old persistence and ingenuity.

cadillackid · 03-31-2021, 05:33 AM

Sweet!!! That’s how I did it! I used a combo of ratchet straps(albeit thicker ones for the heavy part). And the hack. It is in! Did you make sure the flywheel housing bolts were good and tight? Have a friend who’s housing worked loose once because the bolts weren’t tight.

JT20 · 03-31-2021, 10:40 AM

Quote:

Originally Posted by cadillackid

Sweet!!! That’s how I did it! I used a combo of ratchet straps(albeit thicker ones for the heavy part). And the hack. It is in! Did you make sure the flywheel housing bolts were good and tight? Have a friend who’s housing worked loose once because the bolts weren’t tight.

No I haven't torqued them yet, do you know the foot pounds on that? haven't torqued the nuts on the torque converter either, I think I read they are supposed to be 40 pounds, but that seems light to me.

Bouje bus · 09-01-2023, 03:09 PM

@cadillackid

i know this is an older thread, but i can't DM.

i've been reading through all the threads i can find on upgrading my busted AT545 to an MT643, behind a 1997 T444E.

i'm having a lot of trouble locating the parts without spending 1500 just on the adaptors.

i'm at the point of questioning should i consider the allison 1000/2000 if the cost of the MT643 is going to be over 2K.

is the 1000 a straight mechanical swap, plus electrical/TCM. any other hardware parts needed?

thank you

Patrick

the bus is 1998 AmTram 25 ft. used for camping and towing a boat. (probably why the 545 quit)

s2mikon · 09-01-2023, 03:34 PM

Do you know why it quit? Do you have a transmission mounted parking brake?

Bouje bus · 09-01-2023, 03:39 PM

The front pump seal is leaking. Had a minor leak when we bought it. Towed a boat ups some steep hills in the arizona summer time. Didn't know anything about the 545. Now I know, it didn't like that journey. I have hydraulic brakes and the manual parking brake.

s2mikon · 09-01-2023, 04:05 PM

It sounds like you don't have enough cooling for the transmission. Do you have a transmission temperature gauge? Most buses were spec'ed for stop and go flat land routes. No matter what transmission you pick you are going to need more cooling. The transmission mounted parking brake for the mt series is very hard to find.

Bouje bus · 09-01-2023, 04:46 PM

I'm hoping with the lock up torque converter the Mt will fare better on the hills. I've got an additional cooler in my shopping cart if the temps warrant it. I have the brake, I'm just having difficulty finding the flexplate, and adaptor ring. Places that say they have them online don't when I call, and the one place that has everything wants more than the cost of the transmission.

So I'm wondering if the mechanical is more straightforward, is it worth it to spend more and get the 1000?

La Camioneta · 09-01-2023, 04:59 PM

Quote:

Originally Posted by Bouje bus

I'm hoping with the lock up torque converter the Mt will fare better on the hills. I've got an additional cooler in my shopping cart if the temps warrant it. I have the brake, I'm just having difficulty finding the flexplate, and adaptor ring. Places that say they have them online don't when I call, and the one place that has everything wants more than the cost of the transmission.

So I'm wondering if the mechanical is more straightforward, is it worth it to spend more and get the 1000?

Go for the 1000. Somewhat of a hassle, but so worth it.

cadillackid · 09-01-2023, 06:36 PM

the 1000/2000 gives you 1 (or 2) overdrive gears.. if your T444E is 98 or newer it should have the capped off 3 pin connector on the passenger side near the front which is the J1939 datalink.. thats your throttle.. that will be active all the time.. I had to reprogram my ECM with the god mode servicemaxx to get the speedometer to work reliably... the ECM looks for a specific speedo signal related to the phyiscal sender on an AT545.. the 1000/2000 uses an electronic signal..

that said,theres parts you need to source..

1. the transmission - the BEST method is to buy a good running donor bus and snag all the components including the engine computer, install it all on yours and then scrap the donor bus (save the engine if you have a place and arent going to be full-timing)..

2. if a donor bus isnt the way you go.. you need a TCM and wiring harness for the same generation trans you find.. the 01-05 allison 2000's use 3rd gen TCM's and the 06 and up (verify with serial number) use the 4th gen (6 speed) TCMs...

3. allison 1000s come in several flavors.. many of the used ones you find online are GMC duramaxx units.. as are the TCM;s you *DONT* want these.. you need medium duty with SAE3 bell and tail.. and most of the medium duty are 2000 series.. the 2500 PTS is the specific model used on 90% of the school busses.. I went with a 1000 as it was a custom build so it was easy to have them build ne what i wanted in a 1000...

4. parking brake.. I was able to mod my parking brake assembly and make a bracket.. finding an allison 2000 from a hydraulic bus will likely net you all that already installed on it (if its a used take-off)... I see them sold this way often..

5. shifter cable, bracket, and park brake cable should all stay the same.

6. neutral safety / backup lights - find a take-off from an international bus wit hthe harness and you'll likely have this already, might have to ohm the wires to get the right pins to connect..

7. speedo - this wont work right unless you reprogram the ECM "transmission type" from allison AT/MT to Allison MD.. I went through it and even built my own electronic circuit to make it work and it did but was overly complex.. changing the parameter was ultimately what made it work reliably all the time..

8. throttle - you should have the J1939 connecter if your bus is 98 or newer.. the connector will be on the passenger side vaslve cover area and is capped off.. yellow / green / black wires leading up to it.. its a GM weather-Pak connector..

You may also like: