The Stovebolt Site Forums The Shop Area Engine Shop Flywheel Math Problem

I have mentioned in the past that I have an aluminum flywheel in my 261 in my 37 pickup backed with a T-5 transmission. That flywheel is 1" thick. I have removed it and I'm installing a stock flywheel which is 1-3/4" thick. It seems to me that the throwout bearing retainer on the front of the T-5 would need to be shortened 3/4" for this set up to work since the retainer could be hitting the hub of the clutch disc stopping the transmission from slipping all the way into the bellhousing. The splines on the transmission input shaft may need to be extended 3/4" also.
Here are the questions: Does the preceeding analogy make sense? Do I need to cut 3/4" off of the the throwout bearing retainer to compensate for this new thicker flywheel? I have been unable to get the transmission back into the truck and I have decided this is the reason why in won't go back in and bolt up to the adapter.
Thanks for any thoughts suggestions or verifications.
Joe

Joe,

This is all guesstimating on my part as I have never done this swap. If all the clearances were snug before, then your analogy makes sense.

Does the original 1-3/4" have a recessed hub in back. If this is true then it doesn't sit further out on the crank flange and no modifications would be necessary.

If you spend some time with a tape measure, you should be able to make a cartoon that shows the relationship of every component from the face of the bellhousing, which is the front of the tranny, to the face of the crank flange, which is the back of the flywheel.

Sitting at the kitchen table with a cup of coffee, you should be able to dimension the drawing and see any interferences that would cause your problem.

I may be oversimplifying the problem.

Stuart

I say yes to 3/4 inch off the T.O. bearing retainer and no leave the splines alone. You can prove this by removing the trans and put some grease on the front of the retainer. Push the trans in until it can't go in anymore. See if there is a ring of grease on the clutch disc hub. Good Luck !!

There are two T.O. bearings that I know of available. One for the spring pressure plate and one for diaphragm pressure plate. I just grabbed a T.O. that was laying around, the total length is 1 7/8. 3/4 off this T.O. (63-68 diaphragm or spring) eliminates the collar where the fork rides. I'm thinking there is another solution.

Larry

6cot,

An inch and 3/4 (1.750 in) seems a little thick to me so went to the shop and measured mine (from a 235) and it is only 1 inch and 3/16 (1.1875 in). Please ignore this if yours is actually 1.750 in.

Start by assembling things one part at a time- - - - -

First, just install the flywheel, no clutch or pressure plate, and see if the transmission will bolt into place. You should be able to look up into the bellhousing and check the distance between the bearing retainer and the flywheel. If that looks good, drop the trans, hang the clutch disc onto the input shaft, (no pressure plate), and see if things get in a bind when you bolt it up. Somewhere along the way, when you add the pressure plate or the throwout bearing, you'll find your culprit. Yes, it's a lot of work, but on a modification, you must assume everything is wrong until you prove it's right.
Jerry

has this trans worked in this bellhousing before? if not, check the dia of the hole in the bellhouse compared to the dia of the front bearing retainer on the trans

Bill

Thanks for all the suggestions, Guys! I did have the thickness of the flywheel wrong. I re-measured and it is approximately 1-1/4" thick. The old aluminum one was 1" thick. I have checked several measurements today and everything looks like it should work. This transmission has been in the truck already, but on a 37 it gets tight trying to get it in because the end of the body of the transmission barely clears the the underside of the floor when trying to install it. Some of this is caused by new motor mounts that have rasised the motor up and force the transmission to be pushed up at the rear when installing. I'm going to try it again tomorrow. If I can't get it in, I will probably take Hotrod Lincoln's advice and check it in steps. That seems like a good approach and I have found if you systematically approach this kind of problem, you can usually find the answer as quick as if you just haul off and try several things that are not necessarily in some sort of organized order.
Thanks for the input. It helped by causing me to go back and check my work and think through the process. The support and the answer always come form the Stovebolt and the "'Bolters".
I appreciate it very much!
Joe