RRC, Strange Clunk Noise Under Load. Suggestions Needed.

I have a 1990 RRC with Nissan Fd35 Diesiel engine.


The fault began on a day out a few months ago in the mountains, when starting off on a steep hill i noticed one load clunk. I changed many things & the fault has just got worse.


I am hearing & feeling through my feet a clunking noise when taking up drive, the more load the more times the clunk will happen. I can carefully take up drive & accelerate slowly & the clunk/fault will not be present. IF i drive along in 1st or 2nd gear 2-3000 revs & operate the brake while keeping the accelerator pedal constant i.e put more load on engine & gearbox the clunking noise appears. Release the accelerator/reduce the load the fault stops.


I got a helper & a large piece of wood, placed it on all parts while helper took up drive on incline to recreate fault. The loudest noise is heard (through wooden pole) while it is on the pinion/diff housing. Not from engine, not from radius arms or any of other suggested part. From inside the cab its sounds like the noise is in the centre tunnel area.


I took off the front prop shaft (eliminate front diff) & the clunk noise on drive uptake is still present inside the cab but not on the front diff.


If put it in 1st gear & hold the brake down while trying to put away i.e big load but with no movement in running gear the fault is not present, so i dont think its splines on input shaft slipping or cogs/pinions slip.


Things i have done - CV joints checked & regreased, antiroll bar ball joint front & rear changed (both knackered), wheel bearings checked & regreased all round, changed knacked UJ on front propshaft, both radius arm bushes changed, A frame bush checked, splines on half shaft, driveshaft & cv all good no sign of wear. I noticed when I had the front prop shaft off that there is a little play in the transfer box/propshaft coupling.


Note: Handbrake has been sticking on for a good while, now sorted & rear prop shaft sliding member had seized – not causing the problem but could have helped created the problem?


I am hoping someone will recognize these symptoms & help me out with some pointers of where to look next. Then I can fix it & take the missus & little lad on holiday in it like I been promising for ages…..

Ta for any input.

From reading all that I would suggest that it is the pinion/crown wheel back lash in the rear diff.

Not sure of the gearbox you have in there, given that it is not a 'native' engine, but if it is an LT77 (reverse is left and forward) then it could be wear on the transfer box input shaft. This is a splined shaft that comes out of the main box and fits into the centre of the first gear wheel on the transfer box. On the back of the transfer box at the 11 o'clock position from the handbrake drum a plate held on with a ring of 6 (?) bolts. You can remove this and see the gear and the end of the shaft. You are looking for slack between the two.

I'd put my money on the A Frame Ball Joint.
Even almost undetectable play can cause loud clonks on taking up the drive.

i tend to agree with the A-frame ball joint as well. get underneath whilst a helper jumps up and down on the rear bumper, that normally shows the play in the joint.

recchem said:

A frame bush checked

Click to expand...

Don't know about you guys, but I took him at his word

Thanks for your suggestions. A-frame bush checked again & looks like it was replaced recently.

Also would Aframe bush cause the fault when -

"IF i drive along in 1st or 2nd gear 2-3000 revs & operate the brake while keeping the accelerator pedal constant i.e put more load on engine & gearbox the clunking (ratcheting) noise appears."

After doing lots of reading the evidence points in the direction of transfer gear box chain (its a borg warner box). I have read many times yesterday evening about this fault in the classics & moreso in the p38 & the "ratcheeting" noise as decribed by some is a good desription of the noise when the clunk is heard repeatedly on harsh acceleration uphill in 1st gear.

Also the handbrake has been sticking, i know this because when i got under it the drum was very hot after a short journey ( has now been released & is no longer binding ), if this has been an ongoing problem i guess more stress would have been on the transfer chain leading to rapid wear / stretch.

thanks andy, i will look for the plate & eliminate/confirm any slack between the two.

If you have the BW transfer box then you will not find the fault that I described. This relates to the LT230 transfer box only.

recchem said:

Thanks for your suggestions. A-frame bush checked again & looks like it was replaced recently.

Also would Aframe bush cause the fault when -.

Click to expand...

The guys weren't talking about the A frame bushes. They said the A frame BALL JOINT. If the bushes have been done, can you be sure the ball joint was also changed?

Sorry im not the best with terminology, the ball joint in the centre of the A-frame connecting it to the rear axle looks new-ish the rubber cover is clean (compared to the other balljoint rubbers that i not yet changed) with no cracks in the rubber. I have just had someone bouncing on the rear bumper, the only sound was the damper it is nice & tight, no play in either the ball joint or the bushes in the A-frame that i can see.

Problem found, i removed centre console and through a old tear in the rubber membrane covering gear levers used a couple of rachet extender bars to listen for noise. It's loudest on the transfer box. S/H unit found & will be changed at the weekend.

One question, will i lose oil from either the main gearbox or transfer box when i split them? I would expect not but don't want to be suprised with a face full of it.

The main and transfer box fill and drain seperatly, so basically.....no

Thanks.