clunking ideas please

s2a has a rotational clunking which can heard and be felt via the seatbox at around 20mph.

it does this in 2wd, 4wd (though less) and when fwh are engaged or not.

i thought disengaging the fwh and running it in 2wd would mean the front diff/halfshafts and front prop would not turn, so eliminated them.

this left the rear prop and diff or drums.

i've checked the front and rear drums, prop and swapped the rear diff. clunk still remains.

sounds to be at the front to me. if it was perm 4wd, i'd have thought the front prop or diff, but surely these don't turn much (only momentum) in 2wd?

before i whip more stuff off, anyone have any other thoughts? could it be something in the transferbox?

thanks

did you whip the handbrake drum off for a nosey?

^^^ What he says plus I assume you have looked at the UJs ?
Drop the rear prop and try it in 4wd high to see if the clunk goes.

joe27979 said:

did you whip the handbrake drum off for a nosey?

Click to expand...

yeah, seemed fine. i lifted the middle seat and panel out when taking it for a spin. sound seems more from the front, but it's hard to tell.

just i thought nothing should be moving since the fwh are disengaged and it's in 2wd.

divie said:

^^^ What he says plus I assume you have looked at the UJs ?
Drop the rear prop and try it in 4wd high to see if the clunk goes.

Click to expand...

yeah, ujs are fine. you wanting to test the rear prop and diff?

i pulled the prop off and it was fine, inc the uj's and i put in a spare diff, so ruled the diff out.

i wonder if the front is really disengaging or if it's still in 4wd.

tempted to remove the rear prop, jack the front wheels up, have a mate reproduce it and see if i can see anything from the side.

obv being careful what can go wrong, eh!

does noise go when you engage clutch?

joe27979 said:

does noise go when you engage clutch?

Click to expand...

nope still there, if anything a bit worse.

freewheeling it in neutral and it is still there. seems drivetrain or something attached related.

Check your fwhs are actually disengaging - they can stick and drive the front propshaft when you think they're not. Worth lifting the front wheels and moving things around and see if you can feel any play. Clunking like this sounds like propshaft - does it become more of a higher pitched tinkling when you speed up?

oxides said:

Check your fwhs are actually disengaging - they can stick and drive the front propshaft when you think they're not. Worth lifting the front wheels and moving things around and see if you can feel any play. Clunking like this sounds like propshaft - does it become more of a higher pitched tinkling when you speed up?

Click to expand...

yeah i think checking the fwh are working sounds like a plan.

no it only happens around 20mph, it goes away for other speeds.

i did check the front prop and it seemed fine. though, i didn't check to see if it was in phase.. but then this just happened and nothing been changed for a while on the front. hmm worth having a look at.

If 4wd disengaged and fwh you should be able to rotate the front propshaft by hand quick and easy to check.

Blackburn said:

If 4wd disengaged and fwh you should be able to rotate the front propshaft by hand quick and easy to check.

Click to expand...

good point, will do. could jack and turn the wheels too when watching the front prop.

Checking front prop shaft is locked is a bad test - if _one_ fwh disengages the prop will be loose but one set of UJ's and the internals of the diff will be turning - not doing anything any good as it won't be self oiling properly.

My mate thought it would be funny to turn one of mine on and one off...

Not if the box is in 4wd

And your point is - you wouldn't perform that test with the box in 4wd...

No the test was to prove it was not stuck in 4wd!

But you said "If 4wd disengaged and fwh" confused what we're testing for there.

To test 4wd engage / disengage best test is engage FWHs and jack up one wheel at a time:

Engage 4WD, Engage FWH

- Gearbox in neutral: wheel should spin
* if not brakes are binding
- Gearbox in gear: should not spin
* if it does 4wd or gearbox are not engaged or FWH is not engaging
** try to turn prop by hand: If you can then the gearbox/4wd are not engaging
** spin, wheel - if prop turns then suspect this FWH not engaged (but it might be the other)
- Disengage FWH
- Gearbox in gear: wheel should spin
* if it does not, FWH is stuck on
- Rengage FWH - wheel shouldn't spin
* if it does FWH not reengaging
- disengage 4WD - wheel should free
* if not check transfer box / selector

D