How to 'stabilise' my WJ's rear axel

[JimC]

Might have made a bit of a boo boo in my WJ today. Stationary whilst waiting to turn right on a 120 degree turn and getting impatient with the rush hour traffic, I floored it and immediately had knocking and vibration from the rear axel. You have to love the power of a V8

Stoped and had a look and it appears by the clean markings that my rear anti roll bar has shifted about 2cm to the right from where it was according to the markings around the bushes. Done a Clarkson with a hammer to knock it back into place but still getting lots of vibrations and clunking.

Any ideas or is it time to replace the bushes and for me to control my heavy right foot?

[V]

Has the 'A' arm ball joint above the rear axle broken?

[digger]

Hi Jim, I would look at it more carefully. I'd start by jacking up and putting two axle stands under the axle so you can start up and run it on the stands. See if you can see or hear anything. Try removing wheels and do it again. I'd be listening/looking for the vibrations etc.

Bonking noises do come from bushes, especially if they are badly worn but you can usually see by moving them with a lever like a jemmy. See if you can work out why the a/r bar moved to one side. I am not familiar with the suspension set up under your car(which I think is gr8 by the way)  Does she have a track bar(side to side axle locator bar)?  Are the bushes ok in it which would allow side ways movement? Is the a/r bar straight ?  Remove it and inspect bushes.  Put it on a flat surface and see if it sits down level on the flat surface. If one end is higher than the other, its bent. That would be a replacement. They are very difficult to straiten and if you heat it you will likely change the temper(springiness)

If you had leaf springs I'd say it sounds like axle 'tramp' . This is where lots of power tries to 'wind' up the spring which kicks back to straight causing the sort of sound you experienced. Sort of a wheel jumping up and down noise! It doesn't  happen with coil springs  but if you have a duff shocker you can have a similar sound caused by the tyre gripping and repeatedly letting go because the shocker can't control the spring. How old are your shocks? On a normal road car their design life is 30k miles. None the less many folk leave them on for far more than this, often until an MOT picks it up!

A few quick thoughts. good luck I hope they help.

Edited March 21 by digger

[digger]

Hi V, is that instead of a track bar in a WJ?

[V]

Yes. It's technically a simplification of a double triangulated 4-link rear. The upper two links are combined into a single 'A' arm with a ball joint fixed to the top of the axle housing. The 'A' arm triangle with good bushes and ball joint centralises the axle.

[JimC]

Short term, is there anyway to stabilise the rear axel?
Going to go for a replacement A frame so any UK supplier recommendations?

 

[V]

On eBay at the moment there is a complete rear kit including new bolts, swaybar links and bushes, LCAs, A arm and ball joint for £159.93 . This is a lot less than all of the individual parts. The bolts alone are £50, A-arm with ball joint £100, swaybar links £20, LCAs £80-£100.

[JimC]

Took my WJ out for a short drive to try and ascertain where the problems are and my rear driveshaft failed. Luckily I was able to recover it before it became a road hazard so now having to look for a replacement.
The WJ has a 2" puck lift and running 32" BFG's so guess I will need an extended drive shaft, front and rear?

[digger]

Hi Jim, I think (just checking, I'm old fashioned) you mean your propshaft has failed? If so I guess a joint has failed which could easily be your knocking noise. They are not difficult to rebuild or you could send it to a specialist. You will have to if the ears are damaged!  I had very good service from ''Bailey Morris propshaft services'' Feltham , TW14 ORX  tel 02088442265. I think others have too, although there are a number of branches I think. They rebuilt, balanced and retubed my front drive shaft for a little more than a £100 (I had, so sent/supplied my own Spicer joints) about 12 months ago. Excellent prompt service and good job  too!

I lack knowledge of WJ but I've had 3 different Jeeps with a 2 " lift and not needed a longer  prop. Have you had noisy vibrations before?

Hope this helps.

Edited March 22 by digger

[V]

There is a Bailey Morris nearer to Jim.

 

Bailey Morris Limited

Little End Road Industrial Estate, Eaton Socon, St Neots, Cambridgeshire, PE19 8GE, UK

Tel: 01480 216 250

[JimC]

Would Bailey Morris be better than importing an extended drive shaft from the US?

 

[V]

It is worth getting a quote from BM to compare costs. They will be making both of my new propshafts when I install the ZF 8HP70X transmission.

 

I took my current front shaft in for repair after Summer Camp and their advice was to leave my temporary repair as is because for them to repair it properly would involve the same amount of work as building a new shaft. Their viewpoint was that it wasn't worth improving a shaft that was already working good enough, just buy a new shaft when it is no longer useable. The money saved will buy a front propshaft for the other Jeep.

[digger]

Hi Jim, I had a lot of problems when I fitted my Chrysler axle resulting in my having to fit an SYE kit and a new prop which came from 'Tom Woods' in USA. Woods products and service were excellent but the cost including shipping and taxes were horrendous.  Then I moved my attention to the front prop. Long story short, I had it done by 'BM'. I was going to rebuild it, so had bought parts but then found it was bent. They were happy to use my new joints!  I thought that was first class as was my retubed(stronger) prop.  As a matter of interest I asked about having a new prop made to the spec I had had for the rear from the states.  It was less than half  what I had paid for my one!  At the end of the day its a fairly simple piece of engineering if you are a specialist. 

[TimC]

23 hours ago, V said:

There is a Bailey Morris nearer to Jim.

 

Bailey Morris Limited

Little End Road Industrial Estate, Eaton Socon, St Neots, Cambridgeshire, PE19 8GE, UK

Tel: 01480 216 250

I have used these guys, they built me a new front prop for my JKUR, very helpful, great service, not too expensive. I can recommend them.