transmission swap from85 6.9 t088 7.3

[dennis]

I just bought a 1985 6.9with a 4-speed manual and would like to know if I can bolt it up to my 88 7.3 with the automatic my c-6 is toast and I am concerned about using the 6.9 flywheel om the 7.3. Will it bolt up and will there be any issues with balance between the 6.9 and the 7.3.
I live up here in alaska and need to be very flexible with the shortage of part availability with the used parts
Thanks
Dennis

 

[The Warden]

It's a bolt-to-bolt swap...you can use the 6.9l flywheel without any modifications, and the tranny will work just fine, assuming that both trucks are either 4x2 or 4x4 (if one's a 2 wheel drive and the other's a 4x4, there'll be an issue there). You'll probably need to swap the crossmembers, and if the tranny pattern insert for the floor pan is available, I'd go ahead and swap those as well. You'll need to replace the brake/clutch pedal assemblies, and of course any work with the clutch hydraulic system...but, you shouldn't need to do any fabrication or anything on those lines. If both trucks are 2 wheel drive, the yoke for the driveshaft MAY be a different size; if both trucks are the same length (i.e. both are regular cab or both are crew cab), it might be easier to just swap the driveshafts. If both trucks are 4x4, the transfer case will bolt in place with no problem, and no need to worry about the driveshafts unless one tranny's longer than the other (not sure on the length of the C6, but I can tell you that the 4x4 T-19 and ZF5 are the same length).

Hope that helps some...good luck! BTW, welcome aboard!!

 

[towcat]

as far as the trans and flywheel is concerned, it's a drop-in install.
you will run into trouble with the pedal bracket. you're moving between two different generation of trucks.
welcome btw...

 

[dennis]

Thank you thank you
When I bought this partstruck I thought I had just what I wanted. Then I was worried about the flywheel working between the two different size motors.Then it was this dual mass flywheel or clutch thing. I am so relivied that this thing so be able to be swapped out without too much trouble. When I signed on to this web site I went through 36 pages of this forum and did not find the answer so that is why I posted Thanks again for the welcoming I received.
I am a 30 year electronics tech for the FAA and will be retireing in two months. I studied for a year as a diesel heavy equipment mechanic in Fairbanks in 1985. Then screwed up my neck in 1988.I have not done much in the mechanic side of diesel work but I still continue doing the electrical side of dc power and generation. I have changed a lot of alternators from the expensive japanese style regulators to the ford external regulators mostly on little diesel yard lawn mowers and old farm tractors. I amenclosing my e-mail address and will try to help anybody with questions.
It snowed yesterday and when the ground gets thawed out I need to get on my little dozer and get one of my lots ready for the 40x80 metal I bought last year to put some of my toys under cover.I don't normally check the web or my e-mail very much but my wife checks the-mail daily so if somebody has a questionI will get back to you. I will be looking at this site more as I start swapping out that transmission. Thanks again
[email protected]

Dennis

 

[subway]

you are right in that if your newer truck was a stick shift it would have the dual mass set up but like mentioned you can bolt the whole older single mass set up in without a problem. they are both the same height overall and most prefer the single mass set up anyway.

i would be more concerned with the work of putting in the stick shift pedals. not a complicated job but it takes time in awkward positions to get it all bolted in.

enjoy your time here there are allot of knowledgeable friendly people here so dont be afraid to ask.