Shaft Difference between a C4 and C5 ?

[Firewalker]

I could not find a c5 tranny for my 84 4x4 so I took every bodies advice and put a c-4 tranny in the truck. To my surprise, nothing happened but grinding when I started the truck.

Thinking I did not get the torque converter set correctly, I immediately checked but it was ok. After pulling my hair for a couple of days, I finally discovered the pilot shafts were different between the c4 and c5. The c-4 will not engage correctly in the c-5 torque converter, and the c5 pilot shaft will not fit into the c-4. I can not use the c-4 torque converter because the 84 flywheel will only accept a 3/4 pilot shaft(c5) and the c4 has an 1 3/4" pilot shaft.

difference c4 c5
thickness .793" .846"
length 10.06" 9.75"
splines dual 24 26 on TQ end, 24 on C5 end.

Any Suggestions anyone, please help

 

[Fordman]

You would need to use the c4 convertor. I believe that there is a depth difference between c4 and c5 bellhousings, because of the thicker c5 convertor. Was the bellhousing you used a true c4 housing, off a 2.8? If it was a c5 bellhousing, not sure if you can swap input shafts and get er done. I have not tried to intermix c4 and c5 , I have always used a complete c4 setup from a 2.8.

I could not find a c5 tranny for my 84 4x4 so I took every bodies advice and put a c-4 tranny in the truck. To my surprise, nothing happened but grinding when I started the truck.

Thinking I did not get the torque converter set correctly, I immediately checked but it was ok. After pulling my hair for a couple of days, I finally discovered the pilot shafts were different between the c4 and c5. The c-4 will not engage correctly in the c-5 torque converter, and the c5 pilot shaft will not fit into the c-4. I can not use the c-4 torque converter because the 84 flywheel will only accept a 3/4 pilot shaft(c5) and the c4 has an 1 3/4" pilot shaft.

difference c4 c5
thickness .793" .846"
length 10.06" 9.75"
splines dual 24 26 on TQ end, 24 on C5 end.

Any Suggestions anyone, please help

 

[Firewalker]

Actually the bell housing was the original c-5 that I placed on the c-4. A c-4 converter will not bolt up to the flywheel because the pilot bearing shaft on the c-4 is 11.7 inchs wide ane the c-5 is .75 inchec wide. I have to use the c-5 converter. I have been thinking about having the inners of the c-4 converter placed inside the c-5 guts by a local transmission shop.

The other idea is finding a machine shop that would take the c-5 splines for the converter end and attach them to the c-4 pilot shaft.

thanks,,,,,Jack

 

[Redriverranger]

What year is the C4?