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Rear Drive Shaft U-Joint Straps/U-Bolts

Flyfisher

NAXJA Forum User
I've got an '89 Wagoneer LTD (XJ). It's got a 3" Skyjacker lift, running 33's. Other mods are front sway bar disconnect, rear sway bar removed. Sorry it's long..but felt you should know the history.

Recently had issues with rear u-joint on rear driveline after a hard day's wheeling (vibes...obvious wear upon removal). I picked up a new u-joint and straps at NAPA. Things are OK after that.

Following weekend...more hard wheeling (getting ready for club's obstacle course)...broke rear drive shaft at rear u-joint. The "ears" on the shaft tore through and also scored the yoke.

Replaced driveshaft, u-joint, and differential yoke from my son's '88 (donor vehicle). Upon replacement...had serious vibe issues, but otherwise seemed to work OK.

Next week...event and competition. Prior to competion, took Jeep to shop...they were concerned with visible gaps between u-joint bearing cap straps and the bearing caps. Got new straps..still gaps (won't tighten down properly). Got "smaller" straps and I got the Jeep back for $140.

Ran the rally that weekend...first day (rock crawl, hill climb, etc. no problem). Second day, ran the obstacle course (hard) and finished 2nd..but with significant vibes..even at slow speeds. Noticed straps "stretched"...put new straps on, and finished the frame twister and loaded hill climb.

Driving home from the event with a 1st prize in the 35" and under class!! (whoo hoo)...horible vibes. Have confirmed they're from rear..and went to put in new u-joint tonight. Picked up new heavy duty u-joint from NAPA..and u-bolts instead of straps.

Now...here's the problem. The u-joints fit the drive shaft fine...but the u-bolt straps are too narrow for the yoke, but seem too wide for the bearing cap! WTF????

I know I'd need to drill out the yoke to handle the u-bolt straps (instead of straps with bolts), but the u-bolts I was given just won't work.

I was given Precision Heavy Duty U-Joints (#280), and they fit the driveshaft years just fine. I was also given Precision (NAPA) u-bolts (#329-10). They seem too wide for the bearing end caps, yet too narrow for the yoke holes.

Does somebody have better part numbers for u-bolts? How can the u-bolts be too wide for bearing end caps, yet too narrow for yoke holes?

Help!!!!!!
 
No idea on the U-bolt numbers. I've heard its a bad idea to drill out a yoke machined for straps to accept u-bolts.

A more important issue is how are you tearing up the U-joints in the first place? The U-bolt issue seems irrelevant because the straps don't appear to be causing the problem. My guess is at some point(probably axle drooped way down) in the suspension travel, you're maxing out and binding the U-joint. At that point, it doesn't matter if you weld the caps in place. Bind it up and try to rotate it, and spit the joint out.

Re-set your pinion angle or get one of those high angle yokes from (i think) Tom Woods
 
4wd.com has straps & u-bolt conversions for d35s & d44s in their jeep catalog. not the cherokee book, they only list parts for the 35 in that. they have a couple of different listings for the 44 u-bolts. I assume an 89 wagoneer is probably a d44. check out page 319 for d44 & page 321 for the d35. I believe their print catalog is available on line.
 
Rear is D35...and the Skyjacker lift rear springs came with a degree shim "built-in" that tilts the axle up too much (in my opinion). The obstacle course I ran contained both hard compression and extension of the rear axle. I agree that the angles probably exceeded the capabilities of the u-joint, just don't know which way.

BTW...I did notice dents...impressions...whatever, of the u-joint on the floor (underside)...probably cuz my bump stops are missing! I'm guessing that means the culprit was compression, right?

My main question..is what part number u-bolt is correct...or should I just stick with straps and take it easy (and maybe install bump stops).
 
I drilled mine out and used ubolts out of a mid 80's F150 front driveshaft. They are a little too narrow for the holes but with a little persuation they go in just fine.
The reason I did this is because I tore up a couple of those junk straps and finally had enough.... I don't know why they ever started using those stupid things:fuse: I guess they are fine on a street to mild wheeler but once you start really shockloading them that's it!!

Now since I drilled the yoke to use the ubolts I haven't had one bit of trouble and I've even sheared the pinion and 2 axleshafts off.

Drill it out and be done with that problem.

I hope this helps.
 
the strap kit #27018X the u-bolt kit # 29428X, Spicer says you need the u-bolt style yoke to use them, but they are in the business of selling parts, the u-bolt kit is $5.99 & the kit with the yoke is $58.21. I suspect drilling out the yoke would work. the F150 trick sounds good also.
 
OK...well NAPA couldn't help with replacement u-bolts, but did find a much heavier strap with bigger bolts (5/16"). I'm gonna drill and tap the yoke and see if it will last for the next month or so (until I finish my ford 8.8. Then it won't matter anymore!

Thanks for all the help and advice.
 
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