Slow clunk...clunk....clunk under gentle brakes

[Kirky]

Hi Huys,
I've just gone through a mild OME lift from ARB on my 98 Cherokee (2"). Initially I chose a medium rate rear spring kit that sagged a bit (I run an LPG tank in the back as well as standard petol tank) so ARB added an extra leaf. This raised the back of the vehicle and actually improved handling a lot (medium rate springs might have been a bit under-rated for the shocks I reckon). Anyway, soon as the add a leaf was in place I have got this clunk...clunk....clunk coming from the back (I think) under braking. It only happens just before coming to a complete stop (ie at about 5kph) and it doesn't seem to happen just coasting along at this speed. Initially this was also accompanied by a slight surging as though the drums were out of round or something. That has improved to the extent that it is not noticeable, but the gentle clunk...clunk persists. I'm wondering whether the sliding surfaces of the leafs have to wear in a bit as I've only done about 1000km since the add a leaf mainly on smooth roads. I'm a little worried that I have exceeded the drive shaft angles and its one of my uni joints complaining but it drives pretty well as smoothly as it did before the lift and the add a leaf. The only vibration that is noticeable is at between 60-70kph and its nowhere near harsh, you have to really look for it.
Anyone got any ideas or diagnosis suggestions?
Apart from this I'm pretty happy with the lift.
See ya PK

[Richo]

Are the rear leaf packs aligned, ie has one of the add a leafs started to turn sideways and rubbing on the tyre?
Do a search on here, ad a leafs give more drama's than benefit.... Chuck em and go to a spring works and get the rear leaf pack redone with thicker proper leaves.

[banky]

I had the same thing on my 96, it's a pretty out there reason and I don't understand it but it turned out to be a loose upper shock mount in the rear.

[whollsee]

over-torqued wheel nuts? can warp rotor and sometimes drum. Just a sideways thought.

[Richo]

Could also be some brake shoe material falling to bits, tail shaft or uni, a flat spot in a tyre, flogged axle bearings, clunky diff, shocks or bushes, leaf spring bushes.......

It's a jeep thing, drive it till something falls off/out then you'll know. Lol

[rastus2571]

Have a look here first.

http://www.ausjeepoffroad.com/forum/showthread.php?t=62348

Also the add a leaf shackles. Check the alignment and are they tight?

Get that bar and sockets out and worm around.

Take it back and complain. This was not here before....FIX IT.

They might be walking a bit?????????????

Wobble ,wobble grief and trouble.

[rodxj]

Had a similar sound in the ol xj a few years ago. Turned out to be the slip yoke. Whipped out the tailshaft and used a piece of emery paper to clean the yoke as there was a build up of crud on it. If this is your issue, don't forget to use Loctite blue (on the bolts) when refitting the tailshaft. Don't ask me how I know this.:lol:

[Hamsteh]

Are the rear leaf packs aligned, ie has one of the add a leafs started to turn sideways and rubbing on the tyre?
Do a search on here, ad a leafs give more drama's than benefit.... Chuck em and go to a spring works and get the rear leaf pack redone with thicker proper leaves.

The OME Add-a-leaf is a full-length that is the same thickness (and arch) as the other leaves. It's not a dodgy fix like the short and thick AAL's used for big lifts.

[Kirky]

Thanks fellas, there's a lot there to try so I'll have a poke around. They are full length add a leaf by the way. I gather the setup I now have is just the hardest of three options offered in the OME kit. I'll certainly take it back if I can't trace things first, it's a hassle with work getting my Jeep into the shop.
see ya

[Richo]

If it's a slow speed clunk clunk, it could be your rear brake drums are out of round and making your axle rotate slightly against suspension or shock bushes and the pads grab

[disco_nex]

Had a similar sound in the ol xj a few years ago. Turned out to be the slip yoke. Whipped out the tailshaft and used a piece of emery paper to clean the yoke as there was a build up of crud on it. If this is your issue, don't forget to use Loctite blue (on the bolts) when refitting the tailshaft. Don't ask me how I know this.:lol:

My money is with rodxj. I had the same problem after my lift. It's a relatively easy fix.

Is your braking fine? Only the clunking?

[Kirky]

Well, I checked as much as I could this arvo. It looks like Banky had a good suggestion. One bolt on the passenger side shocker was loose. It wasn't finger tight or anything, but it took at least 1/2 extra turn even with a short ring spanner. All the rest were tight. It might not have been the root cause, perhaps the shocker was magnifying an issue with drums out of round, but the clunk is now pretty well cured. Thanks all!
I have to say I'm most unimpressed with the design of the upper shock mounts, they look pretty flimsy and the bolt heads barely cover the slots in the mounting pin. That pin on my original Jeep shockers broke leaving me with an irritating squeak that took some finding! It looks like I should keep my eye on these things. I now carry a spare pin but I gather it's a VERY hard task to push a new one through the rubber bush in the shocker eye (especially away from civilization!).
see ya

[Gildo]

Rear unis?
Get under there and give the tail shaft a good shake.
Change in pinion angle even a little one can show up other parts on their way out.