I noticed a solid metal on metal clunk when I go fast over a dip or with some weight in the back going over a whoop.  My cousin finally suggested we put a twist tie on the rear coil to see if that was the issue.  It turned out to be the coil.  The twist tie was busted off when the coils compressed to the point that they scratch the top of the coil below. 

Has anyone had this before?  Any suggestions besides getting different stiffer coils?

My cousin says he can fab a coilover shock for the rear but that it would be around $1200 for the job.

I'm going to call Calmini to see what they suggest as well.

maybe try better rear shocks? or maybe try adding a bumpstop spacer so the coils don't get fully compressed?

Welcome to the world of the "almost" suspension system. Calmini seems to think that coil bind is an acceptable form of bumpstop  They do a good job on most of it only to not finish the kit IMHO. Stock length struts with inappropriate valving, no choice of spring rates and a heim joint that wears out too easily. I also had issues with the hole size on the diff drop brackets being too large that let the diff move around causing a broken housing which also destroyed the CV and R & P.

I have been running my Calmini Kit for well over 100,000 miles and the spring fully compressing has not given me any troubles except for the powdercoat wearing off.

Zig

Shouldn't be too hard to fab up some bumpstop extensions. Coil springs should never be allowed to fully compress, its just bad engineering. Maybe Zig has never had any problems with the rears but I know a good number of people that have suffered from the front springs sagging.
Struts are a problem with almost every Zuk IFS kit but having custom struts made probably wouldn't be financially viable.
I bushed the diff drop brackets, I've no idea why they made the holes that big.

I was told the rear should not do that unless there was a good amount of weight  back there.  I did have my parents back there so who knows.  It was also suggested an air shock replacement.

Does anyone run one or have a good manufaturer to try?

Or at least a better shock that you've run.  Maybe a Rancho, Doetsch, ?

Here are 2 suggestions I received      any thoughts


Bigger bump stop to try to stop the bind

or

The Rancho 9000 would be a much better shock and it is adjustable, but it's nothing compared to one of the shocks I'm talking about. I think those are over $100 each and for that price, you can get some Bilstein 5100s, which is a much better shock than the Ranchos for the same price. The best think would be to run some King, Fox, SAW, or Radflo 2.5" diameter shocks with resivors. King is about 20 mins from me and they will custom valve the shocks and I could pick them up for you. They run about $600 for 2, but well worth it. You could probably even get some 2" diameter shocks, which I think are a little over $400 a pair and are still valvable.

This is all very odd.  I never had any issues with my rear coils, nor with my diff brackets (before I went with an Anvil, and stepped up to a new level of performance).

Alter your bumpstops. Shocks and springs have other jobs to do.

ive never had the problem with the coils fully compressing even when fully articulated and i eveh have 1 inch spacers under them and over 100 ponds of tools and gear.

A coupla parents can outweigh 100 lbs. of tools right quick..

A coupla parents can outweigh 100 lbs. of tools right quick..

Lol.
The rear shocks can also make a big difference. If the shocks are fully compressed before the springs then they will act as the bumpstops. This is very bad for the shocks although some shocks are tougher than others. Procomps put up with a lot of abuse.