loud chattering noise after Zuk Mod
 

Hi all,

I just finished performing the No-Cut Zuk Mod to restore the sagging rear on my '95 Pickup 4x4, 22RE 5spd. I used front Jeep TJ springs and cut them to 13". The height is maybe an inch over stock in the rear (I may cut them down again if they don't settle) and I'm really pleased with the visual results.

However, I'm now getting a very loud chatter/knocking/clanging sound from the drivetrain under moderate-to-hard braking. If I hit the brakes relatively hard, the clanging begins until i let off the brakes or come to a stop (it slows down as the truck slows down). Just as I come to a stop it almost sounds like a metallic scraping/ringing sound, as the sound is slower and I can hear it in more detail.

I didn't take anything apart to do the mod. I put the rear on jackstands to let the axle hang, and used a spring compressor to slip the springs in. I've done a visual inspection and I don't see anything rubbing. Any suggestions?

This is an old thread but I wanted to post the result for anyone having this problem.

It ended up being a balance weight on the driveshaft hitting the inside of the metal shield that covers the support bearing (only under breaking when the truck pitched forward).

I removed the shield as a temporary solution. But only made it about 1000 more miles before my rear driveshaft u-joint failed. I'm assuming that an already worn driveshaft (210K miles) was exacerbated by the increased driveshaft angle from the ZUK mod.

Rebuilt the driveshaft, cut the springs down slightly to get closer to stock height, and put the shield back. No problems since (2K miles). Still sold on the mod!

with little to no weight on the leaves as the coils are now holding most of the load. axle wrap is greatly exacerbated with coils on top of the tube acting as a fulcrum and allowing the axlew to twist something fierce under heave braking or accel. i ditched the zuk mod on my 86 for this very reason. i broke ujoins on accel twisting it up too much