6 cylinder driveshaft rear ubolt

[cshollon]

I've got a driveshaft from 66 with an 8 inch rear end, but I'm trying to put it on a 6 cylinder 4 lug 7.25 inch rear end. The slip yoke fits fine into the C4 transmission, but the u joint where it attaches to the rear pinion doesn't fit.

Which u joint should I get to fit and how do I swap it out?

Thanks for your help
Cory

 

[phlegm]

So the crux of your problem is that Ford used 2 different u-joints on the 7.25 rearend. I have never had a problem with this, but apparently Ford used the 1300 series U-joints for all C4 installations (7.25 or 8") but for manual transmission installations with six cylinder motors they used a smaller 1100 series u-joint.

Without seeing your setup or more history, I would guess that your original 7.25 rearend was from a manual car and you've stated that the driveshaft is from an automatic (C4) car. So it just won't fit.

I am a member of another forum dedicted to just Ford Six cylinder motors and the solution that everybody says you have to go with is having a new driveshaft built with the correct smaller u-joint end on it for mounting to the rearend.

Now is about the time that a lot of the six cylinder guys start looking for a 5-lug rearend, which they usually redrill for the 4 on 4.5" pattern or a 4-lug 8" out of an early 70's maverick which has the correct lug pattern. Another issue with the 7.25 is that parts are getting scarce, there are no gearsets being produced for it, the pinion crush sleeve is non-existant.

sorry for the bad news, I'm still reading the rules and guidelines around here, but if linking to other forums is allowed I can add some.
-ron

 

[Horseplay]

No issue linking to other sites to help others out here. Just look at some of our avatars!

 

[phlegm]

Ya, yours (Horseplay) is a trixy avatar.. tractorfix.com does not exist. I found the Mustang of the Month thread where it (your tractor) did well at the polls...

A couple threads from Fordsix.com forums (been a member since Nov 2002 after their big forum crash)
This first one is probably most pertinent
Drive-shaft
But you can see that there are a few other threads like this one that touch on the same topic.
8" rear with 7.25 driveshaft

 

[Horseplay]

Ya, yours (Horseplay) is a trixy avatar.. tractorfix.com does not exist. I found the Mustang of the Month thread where it (your tractor) did well at the polls...

That's actually SilverblueBP's tractor. You can tell because it has that enormous sunscreen to protect his :Mark from that harsh Kansas sun.