Sept -Oct 2004:

Now that I had located a new engine, I was faced with a much more daunting task. I had to connect this chevy to the Jeep T-176 transmission. The bolt pattern is not the same, and the large hole in the middle of the chevy bellhousing is a different size than the jeep bearing retainer.

Option 1: Buy a advance adaptor conversion bellhousing. Cost $400.

Option 2: Buy a novak conversion plate from a chevy bellhousing to the transmission. Cost $289. Would require that I buy a chevy bellhousing.

Option 3: It seems that there exists a  vehicle out there somewhere that used a chevy smallblock with a T-4 transmission. I have read that the T-4 and T-176 have the same bolt pattern. Cost $Variable (This turned out to be incorrect)

Option 4: Build my own adaptor. Would require a chevy bellhousing. Would require that I do all the work figuring out clutch linkage, release bearings, and precision alignment. Cost $Free (I would make it at school)

Weighting all the options and costs I decided to go with Option 3. I located such a bellhousing on Ebay, and purchased it for approximately $120.

 

Here is the new bellhousing next to the original jeep bellhousing with the T-176 bolt pattern.

To my disappointment, the bolts did not match up. The bottom two bolts were about a quarter inch off the transmission's pattern. After much fretting and eyeballing, I realized that all was not lost.

I noticed that the transmission had two sets of holes, which are far enough apart to clear the head of a 1/2 bolt. The chevy bellhousing's bolts are in such a orientation that the a simple conversion plate is not an option due to the close proximity of the bolts. I know, its hard to explain, so I drew it up in Solidworks.

A low profile hex head hold would go in the counter sunk holes, and the other four holes would be tapped to accept a bolt from the back side of the transmission flanges.

 

Download Solidworks Part here

 

All the locations of the holes on both bellhousings were measured with a mill and immediately entered into Solidworks running on my laptop. This allowed me to place the two bolt patterns together to in the same coordinate system, so that the new plate could be easily machined.

 

 

A picture of Ryan machining a hole. He agreed to help me make sure I didn't break anything.

 

 

The large hole in the middle was a challenge. I eventually ended up mounting the plate in a lathe and turning it bigger after this initial pilot hole. It had to be accurate to about .005 inches so the input shaft of the transmission would line up with the crankshaft exactly.

 

 

 

I also located a flywheel on ebay. The seller said that he would include an almost new 3/4 ton clutch for an extra $20 bucks. The whole assembly was at my door for $75.  If I would have bought it all new, I could have spent well about $400. Isn't Ebay great.

The great part of the T-176 is the input shaft pattern matches a chevy's. This means that the clutch disk can be used without modification.

However, the release bearing's ID was smaller than the bearing retainer's OD. (The release bearing - left side of picture- slides along the bearing retainer when you push in the clutch.) This was a easy fix, as I machined the OD of the bearing retainer down on the lathe.

Update 8-15-05 - I guess the bearing retainer was weakened by the machining, because it broke. I had to order another stock one and a bigger release bearing. The whole motor had to be pulled just to diagnose the problem.

 

 

I used cap screws the bolt the transmission to the adaptor plate. Hex bolts would not fit in such a small area.

 

 

After two months of solid research and work, the assembly finally came together! Everything fit well, and hopefully the bearings will last a long time.