So I recently took ownership of my dads F-150, and his F-250 6.9l Diesel. Planning a rebuild on the engine of the 6.9. BUT the C6 transmission is shot pretty much it hardly engages, if it does engage it drives fine. I want to put the T-18 transmission into it. Any comments or concerns? I want to to see if it would be worth it to rebuild the entire truck or just part it out?

 

u need a diesel bell houseing

 

Will that come with the transmission or order that seperately. I cant use the automatic transmission bell housing?

 

That depends on where or who you get the trans from - if someone yanked it out to put a ZF5 in chances are the bell will still be bolted to the trans, but if it's a full-service salvage yard where you find the trans they may try to sell you the trans alone and the bell separately... You will also need the pedal assembly from a stick-shift truck, obviously. Possibly a driveshaft swap may be needed too.

The C6 is a cheap trans to rebuild tho, so you may wanna look into that to keep things simple.

 

Automatic trans in these trucks are all one piece, no seperate bell housing like toyota for ex.

 

Yes, also what he said, I didn't notice that part of the question - C6 and E4OD and ZF5 transmissions have an integral bellhousing so you pretty much have to have an IDI- (or 7.3PSD-) specific transmission, while the T18/19 transmissions have a bolt-on bellhousing so at least in theory you could use a non-diesel transmission behind a diesel as long as you have the diesel-specific bellhousing. Not sure about input shaft spline counts tho, if those are any different between different version of the T18...

 

Thanks for the help, how much on average does a C6 cost to rebuild? My father and I were thinking 2500-3000 dollars for it to get fixed and I just told him why dont we replace the whole thing.

 

You can rebuilt under $500 with some heavy duty parts.

 

Anyone know of an existing guide to rebuilding these transmissions. I am not mechanically inclined on transmissions lol as bad as that sounds.

 

As far as I know I have the T18 transmission in my 84 6.9l so i would think that it would be fine on the 86 as well.

 

Yup, as long as the donor truck has an IDI engine the trans will fit any other IDI engine (regardless if it's a 6.9 or 7.3). As for rebuilding the C6 on your own, not sure how much work is involved in it, and what specialized tools may be required.

 

If the donor truck is 4wd does that matter? The 86 is a 2wd and i want to keep it that way.

 

Rebuilding a c-6 isn't that difficult. Here's where I get my parts including a great step by step book for the rebuild. They are real friendly group and will help you along the way.
C4 C6 Performance Transmission from PATC, C6 Transmission

Also here are some pics.

 

All I can say is wow.......that looks really complicated XD. Engines are simplier to me. I guess I gotta learn how to do this so i can use this tranny again.