T-18 Input Shaft in the pilot bushing

[3wheelingCJ]

I bought a rebuilt jeep '79 T-18 to swap out my T-15 . The T-18 came with the bell housing that bolts on to my AMC 304 , minus a couple extra hole.
I compared the lengths of T-15 and T-18 input shafts and both bell housings. Found out that T-18 input shaft is about 1" shorter and the bell housing is about 1" shallower than the stock set.
Mocked up the set-up on the ground (engine just came back from re-build) and found that the input shaft is about 3/4" in the pilot bushing, with about 1/4" left of movement if bell housing is removed. Attached a couple pics.

So, i am wondering if this is enough of depth in the pilot bushing? Have a correct clutch kit and overall everything seems to fit nicely. so this is the last part of the puzzle until i find new issues once the set-up is in the jeep.

 

[tarry99]

What is the stick out length of the input shaft from the face of the Transmission ?

A & A and Novak do make various bushings for the Jeep T-18 ...........but looking at the splines and where they finish as compared to where the clutch disc may go it seems short?

 

[Hedgehog]

Lets help each other here. I'm doing the same thing with a factory mounted T-18 bell housing. The bell housing is 7" deep, the nose of the input shaft sticks out ~0.625" beyond the bell housing which would make the input shaft 7.625" from the face of the Transmission to the tip of the nose."

Bell housing = 7" deep
Input shaft length from Transmission face to it's LONG nose = 7.625"
Pilot bearing = 0.625 long.

While Like you I'd like to see more Pilot bearing engagement, you are getting all the support the 0.625" bearing has to offer.

Can you do me a favor? What is the measured depth of the T-15 bell housing? I find it's supposed to be 7" also. But I remember comparing the two with one being longer or shorter than the other.

If the T-15 actually is 7" deep that would make the T-18 power train 1.87" longer than the T-15 I/we have. If the bell housing actually is shorter on the T-18 that would be good new.

 

[Hedgehog]

Sorry to say it, but your input shaft looks Very rough. While doing my swap I've found that several places sell new input shafts for less than $75, Parts Mike is one of them. At that price I'd consider a new one.

Did you soak your pilot bearing in oil for a few days/hours before installation?

 

[3wheelingCJ]

T-15 Bell housing: 8"
T-18 Bell housing: 6.5" did it while bolted to tranny, so may not be the most accurate. I can re-check tomorrow with it off.

T-15 input shaft: 7"
T-18 input shaft: 6 3/8"

Hedgehog, why do you say the input shaft looks rough? The old pilot bushing is still in, but soaking it sounds like a good idea.

 

[3wheelingCJ]

one more thing, the guys i bought Transmission from told me to use '79 clutch kit. the pressure plate is noticeably thinner that the original.
i measured around 3" on the original, and 2 1/8" on the new.

 

[Hedgehog]

Soaking the pilot bearing is a very old tradition. The brass is "sintered" or porous so it will take up some oil.

Input shaft - It obviously was fairly rusty at one time, you can see the pitting on the nose. Yes, they used emery paper on it to clean it up, but that could compromise it's dimensions and the pits are, well pits. Granted I might be over stating the roughness of your shaft and it might not need replacement ... I would, but I'm paranoid about such things.

The Clutch - I'm learning a lot. Did you know that an AMC cover plates are the same bolt pattern as GM and several others. The Ford clutch is different. Remember your input shaft/disk is 1 1/16" dia (Ford), NOT 1 1/8" - all are 10 spline.

My dimensions are fresh off my Transmission and bell housing sitting in the garage. Yours seem sketchy to me, they seem to be taken from inside the bell housing which is ~1/2" thick. I assure you from the face of a stock jeep T-18 to the nose of the input shaft should be 7.625"

If you still have the T-15 pilot in the crank you have no choice but to remove it. The T-18 uses a much smaller diameter input shaft nose.

 

[3wheelingCJ]

I will check the bell housing depth again, but found a number of sources stating that the stick out length of the input shaft is 6.5" for older t18s.

 

[Hedgehog]

Well.... The jeep bell housing, fork, Transmission and Transfer Case I have is probably wrong then.

You probably know this already, the T-18 fork is different from the stock Ford fork. The Ford fork can be modified. If all else fails you could drop in at NOVAK Conversions and Advanced Adaptors for their idea on the dimensions you might find. Be aware, Jeep alone had 12 different versions of the T-18 .

 

[tarry99]

Judging from the long pilot and the fact you stated it came out of a 79 Jeep obviously you have the Borg Warner Jeep version T-18 which would have a 10 spline 1.125" shaft @ 7.43" in length & power take off port on the drivers side vs the Ford version at 10 spline 1.062" shaft @ 6.5" in length and the power take off port on the passenger side............confirm what you have.

 

[Hedgehog]

I'm beginning to wonder if the differences we are coming up with in measurements is simply how or where we are measuring. For instance there could be several ways to measure the input shaft. I'm measuring everything from the bare face of the Transmission or it's mating surface the back of the bell housing.

 

[3wheelingCJ]

Ok, here are a few more pics for identification and measurement verification. Hedgehog, looks like our shaft measurements match, just used different points of reference.
Tarry, hope the pics answer your question.

 

[Lumpy Grits]

IIRC-Wasn't there a special pilot bearing that fit in the larger area of the counter-bore in the c'shaft for this conversion?
Something like this..........
716156 : Pilot Bushing .670 ID X 1.818 OD | Advance Adapters

LG

 

[Hedgehog]

Your Transmission and top cover is not the same as the '79 T-18 I have. Are you sure you've got the T-18 you think you have? While the input shaft looks correct in both length and the long bearing nose the rest of the Transmission is definitely different from mine. The older CJ T-18 's don't have the desirable compound or "Granny" first gear. Most certainly I hope you have the gearing you want and you just might have that. Where is reverse on your Transmission . For the CJ it should be way right and down with spring/plunger resistance.

Do you have the proper bolt that goes from the inside of the bell housing. The stock bolt has a thinner head with one side cut off. I just went through this with mine. The top to bolts are 7/16" standard thread, the passenger side bottom bolt is a "14" and the "special" T-18 bolt is 3/4". Seems like poor engineering to have so many different sizes.

 

[3wheelingCJ]

So, it have been awhile, but the whole assembly was put together and into the jeep. Everything seems to fit pretty good for a couple items.
The mounting holes for the rear crossmember are now on the Transfer Case instead of Transmission like it was on T-15 /Dana 20 combo. The bushing that I have bolts on, but I have no idea where the torque damper bolts on. The bracket from T-15 doesn't fit.
Anyone has a set up like this? Can't find anything useful on line.
Second issue is the springs for clutch release fork. Can't figure out where to hook them on the bellhousing. Again, any pics of existing setups or any other advise will be a lot of help.

 

[Torxhead]

Thanks for the update. Either thru internet research, possibly thru this forum, or somebody could send you a pic, you fill find what you are looking for.

 

[Hedgehog]

So, it have been awhile, but the whole assembly was put together and into the jeep. Everything seems to fit pretty good for a couple items.
The mounting holes for the rear crossmember are now on the Transfer Case instead of Transmission like it was on T-15 /Dana 20 combo. The bushing that I have bolts on, but I have no idea where the torque damper bolts on. The bracket from T-15 doesn't fit.
Anyone has a set up like this? Can't find anything useful on line.
Second issue is the springs for clutch release fork. Can't figure out where to hook them on the bellhousing. Again, any pics of existing setups or any other advise will be a lot of help.

I'm going through the exact same swap and I'm using your thread as a learning tool.

The torque arm should bolt on between the Transfer Case adaptor, the mount is actually on the stock adaptor between the Transmission and Transfer Case , and the mount. Do you have the stock torque arm? If not it's a simple thing, a ~11" long x 1/4" thick x ~1" wide with an offset for the bushing.

Have you trial fit the support member yet? How does it fit, do you have to drill new holes either in the frame or the member?

As far as pictures go. I google different subjects and switch to images. Generally there are hundreds of images to choose from. Images will also help you narrow down the subject until you can find exactly the image you are looking for.

 

[3wheelingCJ]

I don't know if it's a good idea to follow me lol. This have been one hell of a learning curve.

I took the bracket from my T-15 and cut off a little strip to make it fit.
tried to test fit the crossmember, and the frame will definitely require some holes drilled. Also will need a hole in a crossmember for the torque damper.
Added some pics too. Circled holes line up with the rectangular bushing.

Considering getting a custom crossmember, but not sure which one or the benefits.

 

[tarry99]

I don't know if it's a good idea to follow me lol. This have been one hell of a learning curve.

I took the bracket from my T-15 and cut off a little strip to make it fit.
tried to test fit the crossmember, and the frame will definitely require some holes drilled. Also will need a hole in a crossmember for the torque damper.
Added some pics too. Circled holes line up with the rectangular bushing.

Considering getting a custom crossmember, but not sure which one or the benefits.

One thing you learn when doing these swaps is for the most part what ever you had before will probably not work again without some modifications...........No big deal........fix it , modify it or build another.

Your Transmission looks like an early Jeep BW T-18 ..........shift pattern for Reverse should be over to the Right and up as opposed to the later 78-79 + which is over to the right and down.........covers for those years are also different with the later cover & case having a noticeable kick out on the drivers side for the reverse shift fork inside.............yours should only have two forks inside.

 

[Hedgehog]

My thoughts on seeing your pictures:

Is there a reason why you aren't using the original Transmission . mount holes in the cross member and moving the cross member back with new holes in the frame? If you did that the load on the cross member would not be toward the back, but centered in the cross member as it was designed to be.

How much longer than the T-15 /Dana 20 is the T-18 /Dana 20 ?

Also, your torque arm looks at least as strong as a stock item.