79 Blazer, 4-inch, need info on u-joints

[79cheyenneblazer]

I have a 79 k-5, 4-inch lift with 33's, I put a 2-degree shim on the new re-arched springs and I am still having problems with u-joints. I get a loby vibration when I take off from a stop and the u-joints have in the past been eatting up needle bearings. I put the napa heavy duty u-joints in and they do the same. I have the original drive train still in it, 350/350/np203, so I am asking since there are a lot of you out there with lifts, what do you do about this? Which u-joint do you recommend? I was told by someone that I should put traction bars on the rearend to stop the vibration on take offs, would that help? I just need info on this since I am driving the blazer everyday. Thanks for any help you might have.

 

[trailblazr81]

Well first I got a "1 ton" driveshaft with 1350 U-Joints. Before, my U-joints may last a month if I babied it. After the driveshaft they lasted a few months. What really cured my vibrations was a CV driveshaft with 1350 joints. You will need to get a new pinion yoke for the rear but the CV has never failed me. Even when my U-bolts loosened and my axle shifted it still held up fine. Personally I think CV driveshafts are the only way to go!!

 

[mouse]

The ujoint angles at the TC and rear end need to be the same. By adding the shims it is now probably worse than before. If you cannot get equal u-joint angles, then a CV shaft is a good choice for a fix, but it costs $$$$$

 

[SkulzNBonz]

I have an '86 lifted 4". The first thing I did after I drove it around the block was drop the transfer case 1". No vibes, and ujoint's stay in as long as I let them.

John

 

[tiger9297]

Have a '90 K5 w/4" lift. Mine vibrated like crazy. I bought a new shaft w/ CV joint up front. No vibration at all now.

 

[trailblazr81]

Hmmm. I dropped my t-case and still had vibes.

 

[k5freak44]

4in tc, 1in tcase drop, no probs

 

[79cheyenneblazer]

Yeah I thought about a CV joint, would it be possible to stick a cv joint into the stock driveshaft, by a driveshaft shop of course, or would I have to buy a whole new driveshaft?

 

[mouse]

You could probably use the stock driveshaft as a core, and buy a new CV driveshaft. Not sure if someone can modify the stock one easily, or if a new one is easier. Its probably best to shop around, for the best deal. If money is not a big issue, High Angle Driveline makes (in my opinion) the best, high-end driveshafts available. Still, a competent shop should be able to put something together that would work for less $$. http://www.highangledriveline.com/1350_constant_velocity_joint.htm

 

[ntx78k5]

78 W 4" lift, 1" drop kit for the transfer case and all is well.