My 77 Blazer 4WD is eating rear u joints in the rear shaft like candy.Four in the past two weeks. It is lifted 4 inches and my driveline guy says that GM used the same U joint on these as Ford used on the Pinto. Time for an upgrade I guess. Has anyone done a decent priced mod in this area that solved the problem? Looking for a solution without breaking the bank. My driveshaft guy wants over $700 for a fix with a custom driveshaft and new yokes at both ends. OUCH!! Thanks, Phil

 

Your pinion angle has to be too steep, even the cheapest u-joint on the market should last longer than that. Have you looked into shimming the rear axle? You can buy shims (basically a wedge)to install between the rear axle and the leaf-springs to roll the front of the axle up reducing thepinion angle. That's the first thing I would try. But, I wouldn't think a 4" lift should be causing this though. Are the springs,mounts, shocks, shackles,perches...etc...in good shape? The axle and or t-case isn't moving all over the place is it?

 

Thanks, Lastcoupe, I will check this out. Where can I find these rear axle wedges?

Thanks, Phil

 

No problem Phil, Here's a link to a website that should answer all your questions, and they even sell the shims you will need. http://www.4crawler.com/4x4/ForSale/Shims.shtml Let me know what you decide to do.

 

Checked out my pinion angle and it is right on. Apparently, that's not the problem. I think the PO had broken some u joints and did damage to the yokes at both ends on the rear shaft. Whoever installed the lift blocks over the rear axle, used offset blocks to increase the pinion angle which measures out almost perfect. Since I will have to replace both yokes and U joints again anyway, I think I will go for the upgrade and run the larger 1330 series joints. Like I stated earlier, my driveshaft guy says he does a landmark business replacing older K5 Blazer OEM (Pinto) driveshaft parts. Guess I will bite the bullet and upgrade.

Thanks, Phil Swanson