4wd funny grinding noise

[rickpoland]

Hey guys - time for a bit more help for me stuck (not literally) here in Poland.

Not sure if it's a big problem or not. Had tons of snow here in last few weeks so finally getting to use 4x4 on the Samurai (woo-hoo ). However we have noticed a kind of grinding noise when using 4H. Seems to be coming from the front end so not sure if gearbox or front tfr box related (or maybe somewhere else.

Seems to run fine and the noise really only seems to happen when changing from 4th to 5th or vice versa, or when cruising with foot off the gas in 5th. When accelerating in 4th or 5th gear no problems.

Thought originally it might be to do with the Free Wheeling hubs, but did the checks on whether they were locking properly (thanks for the tips from previous posts) - they are and when locked and in 4wd then wheels don't turn as expected. So 4wd seems to be working fine - just the funny (intermittent) grinding noise from somewhere !

Any help gratefully received - love the car, summer fun and winter fun and practicality and always with a smile on our faces. And love working on it but need to identify a starting point to look at - if indeed it's a big problem or just somethign normal and quirky for a Samurai. just worried that something is wearing and may be a bigger problem later if I don't get it sorted soon

Cheers, Rick

[Jordi]

Its confused me. I had same noises on my SJ but it was in 2wd too. So that was easy it was syncrho hubs and bearings. Just whipped it off and had it refurbed. If its only happening in 4wd then I would say it narrows it down to the transfer box of front diff.

Does it make any noise when you are in 4L?

It could be bearings in the transfer case (which I have also had refurbed). If they are just starting to go then it may only be noticeable at high RPM (you did say it was 4th and 5th gear). Mine grumbled in all gears as when i took it apart the bearings were rolling round in the bottom of the casing.

But there again, you said it was changing gear. Does the gear change ok, or is it a struggle???

Dont know if i've helped or confused the situation more.

Jordi

[rickpoland]

Thanks - I think - Jordi. Like you say maybe confused it more.

Haven't really tried it in 4L to see if it's the same problem - but will give it a test today.

Like you said, 'coz it's only in 4H (and maybe 4L too) then I suspect something in transfer case on front.

But will post more later to see if it's 4L too and wait to see if anyone else had any thoughts/ideas

Rick

[rickpoland]

Hey guys and girls

So tried in 4L yesterday and the same noise but seems to be less of it in low - guess as the wheels are not being driven with as much force as in 4H.

Anyway - decided first point is to check the oil in the front diff - any leaks, not enough etc, check all the connections from tfr case to front diff, front prop drive etc and go from there.

But still any advice on what may be the cause and more importantly the solution will be gratefully received

Rick

[Henry]

First thing i would do is check prop ujs.

[rickpoland]

OK just been reading more general 4WD stuff around the site and seems to be a general concensus that driving on tarmac in 4WD causes a problem. Some say that you should NOT use 4WD at all on normal roads as it causes some stresses as a result of no limited slip differential.

So is it possible that as I was using 4WD H on tarmac roads (basically I wanted to know if it was working OK in normal running conditions) this is what was causing the grinding noise (apparently around the front diff) as the stress and twisting at these speeds (up to 90kmh) was so high.

Just want to know if I potentially have a problem or not. Seems OK to use iin the snow in the woods around here in 4WD as the speeds are never so high that I get to the 4th to 5th gear change where the noise seems to appear.

Not sure I've really got a problem or just that I've been using 4WD in the wrong conditions and generating a problem which isn't really there. All runs absolutely fine in 2WD on normal roads.

Confused - yes I am a bit so any more guidance welcome. Thanks

RICK

[Tramp]

yes in 4ward on the road it doe make funny noises, I accedentaly left mine in fwd and went for a drive after about 30seconds of driving it was making funny noises creaking and shaking like never before!

[Henry]

If you drive on tarmac in 4x4 you get what is known as transmission wind up (google it )

This isnt good and can cause diffs, t-boxes ect to smash. But in slippery conditions such as mud or snow, the wheels can slip independently on each other and release the wind up. If you have driven in 4wd for some distance at some speed... jack one wheel up... this should release it all

[rickpoland]

Nice tip Henry - thanks

But now I know will always use 2WD on road - and even in some snow and ice almost as much fun remembering how to drift around a corner balancing power and steering in a RWD 2WD car. Teaching my girlfriend some winter driving skills and scared her half to death with some big slides but even she is starting to see the fun in a RWD car in the snow.