New Transmission

[kelton]

I am looking into replacing or rebuilding my C-6 transmission for my 1970 F-250. Does anyone know of a place that does good transmission rebuilds near Atlanta? My other option would be to get a "new" transmission. Any info on a place that sells them would be great. Also if I replace the transmission would their be anything better that the stock C-6 that could be easily swapped out maybe a AOD? Thanks for the help and

[fordman]

c6 is the best transmission for the 360/390 engines. you wont find a AOD that will bolt up to a Fe. they didnt make them.

[kelton]

I have a stock 390...most of the truck is stock camper special out fitted with every option. Is their away to get overdrive on a C-6?

[kelton]

How long would you guess it would take to rebuild a C-6? Also Would you recommend anyone that sells rebuild kits? Thanks for all the advice.

[BobbyFord]

How long would you guess it would take to rebuild a C-6? Also Would you recommend anyone that sells rebuild kits? Thanks for all the advice.

I rebuilt my C6 and installed a shift kit in about 6 hours. Of course the trans was already out of the truck. I would have done it sooner but the case was extremely dirty. Do a Google search for Transtar Industries, they have high quality kits and probably have a location near you.
It took me about two hours to get the case this clean.

[Mancar1]

How long it takes would depend on who is doing it. Remember when you have a shop do it, yours isn't the only job they will have. If it is you might consider somewhere else. Local parts stores can help with getting the rebuild kit, or order online as mentioned above. Try it yourself, put it together the reverse of taking it apart. I would wait until you have the time. Not a good idea to start the job and get back to it every couple weeks. Unless your memory is a lot better than mine If you don't have one, get a good manual. Dedicate at least a weekend to it.

[Mancar1]

Bobby, That trans work as great as it looks? Of course it does.

[Hawkrod]

Well I notice you didn't say what engine you have but I will try anyway.snip.

Actually, he did say what engine he had because he specifically noted "stock C6" and the only stock C6 came behind an FE that year! Hawkrod

[kelton]

Yea I have x-mas break coming up 2-3 weeks I think so good time to rebuild it i think. You noted a manual? Any one you recommend? And that is a beautiful transmission you have their!! Thanks for the help also as a side note is their any bolt on overdrives for the C-6?? I have seen them for 3-speed manuals and the 4 speed manual.??

[1971ford]

How long would you guess it would take to rebuild a C-6? Also Would you recommend anyone that sells rebuild kits? Thanks for all the advice.

I rebuilt my C6 and installed a shift kit in about 6 hours.

You're insane.

[kelton]

I am very much liking the sound of doing the rebuild my self and it gives me the chance to get to know my great grandfathers truck. Are their any special tool that I might need? I have a large selection but idk if their is some ford special tools?

[mkpj1]

Check it out.

http://www.badshoeproductions.com/

Spring compressor is the only tool you will need to make it slick like Bobby did it. You can go without but you will need patients.

[1971ford]

I'd suggest not just replacing all the seals/o-rings though.

My dad and I tore my 429's c6 apart and layed it out across the garrage floor, ever little piece of it. I bought all new seals/o-rings and a TCI valve body (not a big fan of TCI either but that might be because i blame stuff on the valve body that i am probably at fault for) and we got it all back together and it still slips if you let it shift by itself. this isn't really a problem for me because I shift it manually with an art-carr shifter and i have a fully built, finned c6 with 40 miles on it out of a trophy truck that's going in.

But the point is I would post pictures of almost all the parts so the guys on here can critique them. I didn't, and apparently some of the parts that I didnt notice any wear, must have had wear.

[BobbyFord]

You HAVE to disassemble the entire transmission, including the valve body. C6's are easy but there are little things to look for...
There are check balls on each apply piston for each clutch pack. After the piston is clean, put your lips on the apply side of the check ball and make sure it holds, if it doesn't you can reset the ball against the bore using a brass drift (so as not to dent the check ball). You can air check the trans after assembly, before installing the valve body to insure that there are no piston/o ring leaks. You can air check the intermediate servo. You have to disassemble the valve body to check the separator gasket. A lot of rebuilders don't even install a new separator gasket when they rebuild or install a shift kit because they are so prone to failure.
Here are some pics of separator plate gasket failure on the trans that I acquired for my swap before rebuilding.
In these pics you can see the split in the gasket, even before separating the halves of the valve body:


Here you can see what the gasket really looks like:




Also, unfortunately your trans is upwards of 40 years old and there's no telling what hack may have been in there before to sabotage your current endeavours.
Here's my one-way sprag that the previous aforementioned hack screwed up on the previous attempt at overhaul:



He installed the springs on the wrong side of the rollers. I'm sure his heart was in the right place but his head clearly wasn't.
It's not enough to lay the parts out as you took them apart. It's also knowing where the parts really belong prior to disassembly. It's important to have proper instructional reference material before tearing in.

[1971ford]

You HAVE to disassemble the entire transmission, including the valve body. C6's are easy but there are little things to look for...
There are check balls on each apply piston for each clutch pack. After the piston is clean, put your lips on the apply side of the check ball and make sure it holds, if it doesn't you can reset the ball against the bore using a brass drift (so as not to dent the check ball). You can air check the trans after assembly, before installing the valve body to insure that there are no piston/o ring leaks. You can air check the intermediate servo. You have to disassemble the valve body to check the separator gasket. A lot of rebuilders don't even install a new separator gasket when they rebuild or install a shift kit because they are so prone to failure.

He installed the springs on the wrong side of the rollers. I'm sure his heart was in the right place but his head clearly wasn't.
It's not enough to lay the parts out as you took them apart. It's also knowing where the parts really belong prior to disassembly. It's important to have proper instructional reference material before tearing in.

yep... we tore it all down, but not the valve body because I bought a brand new one. We checked the check balls and did what the manual we bought told us to do.
Must of been something we missed. Maybe in a few years when we do something to the built c6 I now have going in the race truck I'll tear it down and spend more time on it to understand it.
But the highboy has a manual and all i see is gears so even if it ever does need a rebuild I'd be able to do that!