Herky Jerky Beach Driving

[igsmith]

First time poster here...i have a 1982 NZ MOD Stage 1 (FFR). Bought in 2007 off eBay from a seller in NZ. Car seems very strong mechanically.

However...sometimes when i drive in soft sand on the beach and traction is limited, I get a very violent "herky jerky" reaction from the vehicle. It made me think if i kept it up something would break. I tried it with the vacuum diff on and off with no change.

It doesn't seem to happen when i have decent traction, even in sand.

Any idea what could be causing this?

Thanks so much!

[disco2hse]

I have had the same thing. Check that the wheel bearings are sound, UJs are not worn, and that the centre diff lock is actually engaging. Also, this can occur when you are in the wrong gear, that is the engine revs are too low. I assume also that you were in low range and 2nd or 3rd.

[map1275]

In other words, drive line 'Back Lash'.

All the free movement being taken up and specifically noted during sudden throttle operation.

[igsmith]

When I was driving, i was in High, and in first gear. It seemed when i got up to speed it went away. So it was likely that my problem was engine revs too low.

I will try it the next time in Low gear.

Thanks.

[djam1]

I think you will find that its axle wrap with the springs winding up and releasing if you get out and watch underneath while its doing it and you will see what I mean.
Dont let a Stage 1 do it too much as it can do a front axle.
You are probably better off to deflate your tyres a little bit.

[disco2hse]

Could that be caused by worn bushes on the shocks, or the shocks that need replacing?

[5988]

Could that be caused by worn bushes on the shocks, or the shocks that need replacing?

no, its due to the design of the springs, and there resistance to twisting that way, shocks may help reduce the amplitude of the movement but it will still happen
essentially if it happens the solution is to alter your driving to avoid it

[disco2hse]

Thanks. I know what it is. The question was if it is exacerbated on the Stage 1 when the shock bushes or the shocks themselves are worn. The ex-army uses standard front springs IIRC.

For igsmith's sake here is a linky that explains what it is http://www.4x4wire.com/jeep/tech/susp/axlewrap/

To change your driving style, essentially take your foot of the go pedal a bit.

[5988]

Thanks. I know what it is. The question was if it is exacerbated on the Stage 1 when the shock bushes or the shocks themselves are worn. The ex-army uses standard front springs IIRC.

For igsmith's sake here is a linky that explains what it is http://www.4x4wire.com/jeep/tech/susp/axlewrap/

To change your driving style, essentially take your foot of the go pedal a bit.

sorry,
tired springs would probably encourage it

[disco2hse]

Good point. The springs are likely to be the originals, that would put them at 26 years+ old. They would be getting tired by now and no doubt flattened significantly too.

[arturo126]

I have that problem too, and my transfer box get damage. I have problems with traction and my diff doesn´t work. See the transfer box oil too.

[disco2hse]

From what I recall Arturo we could see a lot more than just your oil

[igsmith]

So my LR has original springs (although they don't feel soft) and new shocks.
And it seemed to happen at hi or low speeds.

Anyhow, i reduced the tire pressure to about 25psi, put it in low gear with the Diff Lock on, and was fine in 2nd or 3rd gear. No issues at all.

Thanks for all of your advice.

The only issue i had today was that my Diff Lock light wouldn't go off after i disengaged it. It took a few times for it to release/go off.

Ian

[5988]

back up a coupple of metres when you disengage it, usually releases then
though if its sticking on that would suggest transmission wind-up and that really you don't need it locked

[arturo126]

Sorry MAP error on posting not that one.