U Joint Cap Size

-
74desertduster

74desertduster

Well-Known Member
Joined
Apr 19, 2009
Messages
508
Reaction score
3
Location
Tucson AZ
Going to do the U Joints on my 71 Swinger with a slant six, automatic trans.

Was looking up the joints and there are two listed. One has a 1.126" Cup and one has a 1.078" Cup.

Is there any way of knowing what size I need before I drop the shaft and check one? Any method to the madness?

Will the rear be the same as the front since I can measure it once I unbolt the strap?

Many thanks!

Brian
 
74desertduster said:
Going to do the U Joints on my 71 Swinger with a slant six, automatic trans.

Was looking up the joints and there are two listed. One has a 1.126" Cup and one has a 1.078" Cup.

Is there any way of knowing what size I need before I drop the shaft and check one? Any method to the madness?

Will the rear be the same as the front since I can measure it once I unbolt the strap?

Many thanks!

Brian
Click to expand...

Well, if you REALLY want to know, go to Harbor Freight and buy a cheap caliper and measure them. That way, you'd not only know FOR SURE, but you' have a new caliper!!!

But there's a VERY GOOD chance that the U-Joint you need is a 7260.... I've never seen a /6 drivetrain with a 7290 (the larger of the two sizes.)

Good luck!
 
Bill Dedman said:
Well, if you REALLY want to know, go to Harbor Freight and buy a cheap caliper and measure them. That way, you'd not only know FOR SURE, but you' have a new caliper!!!

But there's a VERY GOOD chance that the U-Joint you need is a 7260.... I've never seen a /6 drivetrain with a 7290 (the larger of the two sizes.)

Good luck!
Click to expand...
Yup, if the car is stock, it should have the 7260's front and rear.
 
Looksy here: see difference in center section? 7260 looks like it goes right from the center section to the caps, the 7290 has a little sumpin-sumpin between the center and the caps.
Inside%20lock%20UJ%27s%20copy.jpg
 
Good visual aide....picture = good.

Looks like I have 7260...now the fun begins. Need to change the trans seal too while I am at it.
 
piece o cake. Prepare to spill a little ATF out the back, no way around it. Harbor Freight sells a trans plug that slips in there in the absence of the yoke to keep the red stuff in, but cut aspirin bottle works too in a pinch. New seals dont have the rubber boot as the OEM ones did. A little RTV smeared lightly on the sealing surface of the seal to trans is good insurance.
 
Got me a Timken seal and his has the boot...so I am all set. Well, except I still need to do the job...lol
 
So I got them in...job went about like I expected, no real problems...easy, all things considered.

I still have a rhythmic vibration around 40mph and above....it does it if I put the car in neutral and shut down the engine and coast, so the engine is not doing it. My back tires are old as dirt so that's my next thing to change.

I guess the drive shaft could be out of balance.

One of the old U Joints had some play in it and I thought that was the vib....any other ideas?

Thanks for all the good help!

Brian
 
Bent driveshaft most likely.....get the car up in the air and spin it. A good size dent will do it too.....
 
Didn't notice any dents when I had it out but will jack it up and take a peek with it spinning....when it cools down some.
 
If you put the car up on frame stands and let the rear sag on the leafs, you might be able to pick up the vibration when its in gear and someone is monitoring the speedo. Try it without the tires off to isolate the problem. Dont know if full rebound is going to make your pinion angle part of the problem though. Of course jackstands under the rear axle and no tires will isolate the tires too. Many times its just a thrown weight off a rim or a bulged/broken belt tire.
 
You must log in or register to reply here.
-

Back
Top