First post on the 1200 site. Been lurking for some time but had trouble logging. So here id=s my dilemma. I just installed 2" lowering blocks on the rear of my sedan, Things seemed fine until I started hearing a slight clunking noise after applying the brakes. After poling around I have discovered that the axle is rolling a few degrees on the new block. The blocks have the locator pin but are a hollow machined type block. In addition I was not initially able to keep the U bolt locators on the top of the axle in place. Could that be my problem? AND I am now also hearing a slight grumble like vibration while cruising in forth gear. The blocks do have a few degrees of angle /wedge to them, I would have thought this would keep the drive line as straight as possible due to the 2" drop.
With the car on the ground and the parking brake on, I can move the car back and forth about a half inch watching my rear diff of course moving as well.
Any insight would be appreciated.
Sorry about the long winded post.

It is not safe to drive! There should be no movement of the diff rocking.

The locating tabs may be too big or small on the leaves or the diff and the u bolts should be tight

This is an accident waiting to happen sorry

Agreed. I wouldn't drive that until you get it fixed. The quick solution is to lose the blocks and restore it to normal.

The locating pins and proper torque of the U-bolts are essential.

I will recheck my torques. What is the purpose of the upper u-bolt/axle collars? If all checks out I may try reversing the spring pack, I will start reading up on this technique. Why is that no one else is having this problem? I will try to post some photos tomorrow to see if anyone spots anything obvious.
Thanks for the quick answers.

My under standing is the collars equalise the pressure of the u bolts and help locate them correctly.

Flipping is in the wiki don't flip the main leaf.

But if you have difficulty with blocks I hope you have the skills and knowledge to flip leaves safely.

I'm not having a go, just,make sure you do it safely

I thought that the blocks would be a fairly no brainer project. Although it is my first time using them, I have done other suspension work. I feel confident in my abilities to address most of the mentioned problems, but also don't want to chase my tale and possibly destroy my diff in the interum. I was perplexed though as to why I had not heard of many other people having the same problem hence the original post. What is the consensus on the angled blocks I used (approx.5degrees)?
Ultimately I think I will look into rearranging the spring pack as that will fit my budget at the moment. and also seems as safe and dependable as re arching.

Angle blocks are used if you angle the transmission to match. This is not done unless lowering more than 3 inches.

Flipping results in poor handling and a too-stiff ride.

The collar that goes over the axle tube is to match the u-bolt diameter to the housing diameter and on a sedan incorporates the shock mount.

I have tried to post that very image with no luck. (My next project is how to post pics, of course its different than Ratsun, and yes I will reread the wiki)
Sedan #25 is the part that I left off due to interference with the new ubolts.
Do you think that the angled blocks are playing a role in my lack of success?

Do not know, but inspect the part below #25 to see if it is cracked. That allows the rocking motion which will cause increasing problems.

If you plan to reuse the angle blocks, be sure to angle the transmission the same amount.

Poor handling my backside! My car handles way better now, obviously not as good as reset spring rates but much better than with blocks