advise on changing flexplate/flywheel please

[welcomehome]

2000 international 3800 t444e bluebird with at545 transmission.
i recently got my first bus. lots of starting issues over this last 4 months of having her. upon pulling the starter i noticed worn teeth on the bendix gear and upon closer inspection i saw multiple spots of broken teeth on the flexplate. so i have to replace the flexplate.

multiple people that i have talked to have told me it is a hard job , and that they have done it, but it is a pita. however all of these people have did it on a manual transmission, which im learning, makes it a flywheel for them.
shopped around and found shops expecting from 1500 to 2000 to change out the starter and flexplate including parts and labor.

blessed with a concrete driveway and understanding inlaws whose house we are visiting, i see no other financial option than to study up on it and do the work myself.
i have been down there quite a bit looking at all the things i would have to disconnect to take down the tranny in order to pull it out from under the bus to get the flexplate off. i wonder if there are any idiosyncrasies about this international 7.3 liter engine that i need to know or special tools i will need to do the job? what other seals or other things would i also need to do?

does anyone have any advise on this job? thank you so much.

[cadillackid]

I would trend toward dropping the trans.. that 545 with its converter is going to weight a LOT more than a couple of guys can lift.. you will want a transmission Jack.. a heavy duty one with a large base..

it sounds like you have your starter off already.. if not be careful it is quite Heavy on a diesel bus...


draining the fluid you will have 20 quarts or more in fluid so I suggest buying a cheap plastic baby pool to drain it into ...

with no details filled in about your bus I dont know if you have a hydraulic brake bus or air brakes... if its hydraulic brakes your transmission is also the parking brake so you need to take that into consideration when chocking and stabilizing the bus..

if its like my little bluebird it sits low to the ground.. if its a full size bus on 11R22.5 tires you will have room to back the transmission off and lower it easily...

the top bolts are accessible from the inside of the bus under the inspection plate which is in the center floor..

if it were mine I would probably check the engine rear main seals and the transmission front seals.. both are notorious got going bad..

I dont know your mechanical skills and see you are on low budget .. im the type that would replace all the seals when I had it down.. front / rear, engine rear main seal.. but thats just me..

others can chime in.

-Christopher

[Tango]

On some rigs, you have to first jack the bus up and put it on stands high enough to drag the tranny out. Chris is right...the 545 is a big, heavy chunk of metal that will definitely require a jack and something to roll it about on. Best of luck with it

[cadillackid]

if he is just changing the flex plate the tranny may not need to do anymore than just be placed off to the back or side a little ways to get to the flexplate bolts.. if not replacing the tranny seals, the converter and tranny can stay under the bus on the jack..

I would suggest a platform transmission jack with chains over the transmission.. thats how Ive always R and R transmissions on my hotrods.. (and ive done it alot as I tend to blow stuff up when hotrodding)..

-Christopher

[bluebird90]

First off, It's a bit easier than you think. You do not have to drag the trans all the way out. You only have to separate it by far enough to get your hands and tools in there. (6-10 in ). The trans is most likely only hanging off the engine with no trans mounts. If the mountings are at the trans bell housing you will need to support the engine. USE A GOOD TRANSMISSION JACK! These things are heavy. This is something you could do in a day.

[cadillackid]

I know on both of my AT545's theres no mounts for the transmission other than the bell bolts....

likely just.. shift linkage, modulator wire (in 2000 the 545 is electronic), bell bolts, center carrier bearing plate loosen enough to yank the front driveshaft.. torque converter bolts and out... (not in the order I described).
-Christopher

[welcomehome]

she's the handy bus type; the medium size one with the wheelchair lift. she has hydraulic brakes. if i do need to jack up one side of the bus to make room to get the tranny out, what size jack do i need to get?

i see that i will need to rent a transmission jack as well.

yep, ive now taken that starter off twice. 3 to 4 times the size of the starter in my old vw vanagon. heavy as heck.

i absolutely do want to change all the seals and other preventive maintenance that i can while the tranny is separated from the engine. so far ive heard that i need a rear main seal, which may be the same as the rear oil shield that the shop suggested i need, and the transmission front seal. is there a kit with these in it or should i buy/order them separately when/wherever i can find them? would flaps have them or do i need a specialty shop?

im hoping to order and install a new bendix on the starter instead of buying a new $350 starter. that is assuming that i can figure out exactly which delco starter it is considering that the info on the label of the starter wiped off when i tried to just wipe the grime off the starter. anyone know how to identify a delco starter with no label?

and also i need the flexplate itself, and new bolts. is there a flexplate kit for my bus? im probably looking for them in the wrong place: mostly ebay.

im glad you think i could do this in a day. that translates to me as, (as slow and careful as i am when im working on mechanics)that i could get this done methodically within a week. i was careful to let the inlaws know it may take us 2 or more weeks considering if we have to order parts.

where are there diagrams of my bus? any such thing as like a chiltons or haynes or similar repair manual for my vehicle? google and youtube dont seem to be very forthcoming with directions and info on changing the flexplate on my bus. i wonder if there is a step by step how-to out there somewhere on doing it for my bus?

its so nice to have a forum here to get advice from people not trying to sell me overpriced parts and charge me $100 an hour for labor.

[welcomehome]

so it almost seems like i could start by disconnecting everything off the tranny in preparation for lowering it. ive watched alot of videos on youtube about changing the flywheel or flexplate but they are all for smaller vehicles. should i expect that it will be the same process for my bus, but just with bigger components?

ive looked high and low on the net for diagrams/schematics for my bus. i did find a usb stick being sold that says it is for all international/navistar vehicles that is a repair manual but they want $500+ for it. apparently its the one that all the official service bays get.

center carrier bearing plate: when i pull the front driveshaft, is there any certain direction it has to be pulled, or put back in? or does it find its right position upon insertion?

do i need to take the torque converter off, or do i leave it attached to the tranny when i take it off and just disconnect the bolts of the shaft off the back?

i imagine when i get the tranny down its just a matter of unbolting the bad flexplate off the tranny and bolting the new one back on?

thank you so much. i know ive got alot more research to do on this before i dive in. but im feeling more and more confident in my ability to do this myself. obviously if i could afford it id rather pay a professional to do it who is well trained. but being broke i realize either i do it myself or just dont have a bus/home anymore. thanks for helping.

[bluebird90]

The flywheel will most likely consist of 2 parts. the flexplate and the flywheel.If you have this setup, you only need the ring gear, not the whole thing. You use a hammer and punch to knock off the old ring gear, use a torch to heat the new ring gear all the way around, (not red hot), drop the gear on the flywheel, let it cool. One trick I have done if there is room is to get a couple of looong bolts , thread them in the top of the bell housing and use them as a guide to slide the trans back 6-10 inches .Use them only as a guide, not trans support.

[welcomehome]

im confused. ive looked elsewhere on the web and thought i had learned that a flywheel was for manual transmissions and a flexplate was the equivalent used on automatic transmissions, like mine. the comment seems to be saying that i am mistaken?

[bluebird90]

On large vehicles there is a "flywheel" that has the weight the engine needs to run smoothly. There is also a separate part called a flexplate that attaches to the torque converter. Take off the inspection cover on the bottom of the flywheel housing and you will see what I mean. You may see both parts.

[bluebird90]

One thing I forgot to mention. There are 2 sae housings that these engines use. #3 and #2. If there is a steel reducer ring between the flywheel housing and the the AT545, you will have the setup I have described.It's a #2, If you don't have the ring then you may have only a flexplate. It's a #3.

[Diverdude0075]

Hi Folks, I've bought my allison 2000 transmission to upgrade from my AT545, and have ordered all the parts and pieces thanks to the detailed Redbyrd post (thanks Christopher!). My flex plate is also missing teeth and needs replaced. My question is where in the heck should I order from? When shopping do I just need to ensure compatibility with the t444e engine or does it have to match as well? I have the torque converter that came with the transmission. If I could save money and just get the ring replaced that would even be better. I will have to pay someone to swap the rings out if I go that route though...

[cadillackid]

id look for a used flywheel for an automatic on vaanderhaags or such.. you can call the navistar dealer to get the part number for your bus.. the same piece that the 545 used works on the 2000. remember ALWAYS loctite your converter adapter ring bolts and converter bolts..

[welcomehome]

i went to the international dealership in person for mine. they were really helpful and had me a brand new flexplate pretty quick. i dont remember exactly but i dont think it was that much considering what a large piece of metal it is.

[turf]

a good jack will make it easy. a bad one makes it a long day.

i had my 545 up and down 5ish times when i swapped it out. down is easy, up is harder.

the flex plate might be damaged a bit but i bet most of the damage is on the starter.

both my starter and flex plate had corners nicked. not sure why but the flex plate has a direction to it so you can't just turn it over and use the back side of the ring. there is probably an offset on the flex plate.

when my starter finally got so bad it wouldn't catch the flex plate anymore, i replaced the starter. that solved the problem for now. there are only like 10 teeth on a starter and maybe 200ish teeth on the flex plate. if the starter fixes your problem, i'd call it a day, and wait for a new transmission before i touched the flex plate.

[Diverdude0075]

Thanks Turf. I’m guessing it’s the flex plate missing teeth cause it’s intermittent. I’m dropping the transmission to replace so we’ll see. I found just the ring to replace if that ends up being the issue. Where’s a good place to buy a starter if it ends up being that?

[turf]

I'm sure you can find a good truck parts place in Albuquerque.

my starter came from napa. no core even.

for my vin specific truck parts, i use a place in southern colorado called Arkansas Valley Diesel. they have a great mail order business and sell a lot on ebay.

my starter problem was also intermittent. you can see the nicks on the flex plate, but the worn starter was my main problem.

[Diverdude0075]

Thanks! This gives me more ideas!

[welcomehome]

i think i got my starter from napa too. i remember buying one from oreilleys that was cheaper but wouldnt line up right, so i had to return it. my starter that did end up fitting was a delco-remy, the same model that came off it.