Offroad-Express

Has anyone had experience with diagnosing and repairing a rear diff whine?

The whine starts up around 55km and gets progressively worse when getting up to speed on the open roads. It's not too loud. With the radio on at normal volume you can only just hear it. More annoying than anything.

As soon as you take you foot off the accelerator the whine stops. Repeatedly doing this shows that the whine only occurs when the diff is under load.

I replaced the rear diff oil (LSD) but it didn't help. The old oil seemed in good condition with only a very small amount of fine filings attached to the plug magnet.

Had a mechanic friend take it for a run with me and he thinks its a bearing in the diff. He also thinks it can be tricky to replace (hasn't done one on Terrano himself, but has been told). Is this the case? Does anyone know a good mechanic in the Tauranga area who can do the work?

Are there any other possibilities? I read something about checking the drive shaft. It definitely sounds towards the rear of the vehicle and I can't feel any abnormal vibration.

Truck has 148k on the clock. Assuming it hasn't been wound back (no tell-tale signs) should the diff have gone this early?

Thanks guys, any advice is appreciated!!

pinion shaft bearings are wearing. To much lash.

they need

A reshimming
B replacing

Get under the back of the truck and give the drive shaft a wiggle near the rear diff. there should be no up or down side to side movement and could be some lateral movement if the bearings are worn.

They can go anytime. damaged or leaking seal. A little moister in the breather from a creek crossing or backing a boat down a ramp is all it takes to start the proccess.

it isn't too hard but it is something you would rather have a specialist do if you haven't seen it done or done it your self.

It involves removing unbolting the drive shaft then loosening the pinion nut behind it .

then axles from the diff housing(pulling them out enough to clear the diff head carrier bearings.

unbolting the carrier from the front of the axle housing

Undoing the carrier bearings removing the diff head, finish undoing the pinion nut slide out the pinion shaft and replacing either the shims or bearings or both.

also the pinion nuts and drive pinion shaft seal are a one time use item and usually it pays to do all the bearings on the complete rear axle since it's in pieces anyway.

The hard bit is getting the correct shims in the right places to locate the face of the pinion against the face of the crown wheel.

pull the head out and sent it up to Lee at "Diffs are us"
in otahuhu auckland

he will sort it out and his prices have always been reasonable

here you go it will save the search

4A Kaka St Otahuhu Auckland 2024

092700855

mudlva wrote:pull the head out and sent it up to Lee at "Diffs are us"
in otahuhu auckland

he will sort it out and his prices have always been reasonable

here you go it will save the search

4A Kaka St Otahuhu Auckland 2024

092700855

Thanks Mudlva. Gave Lee a call. He is saying that its just not worth trying to repair it. His experience has been that you must change the crown wheel as well as bearings and shims. The crown wheel is going to cost about $2000 from Nissan and you still have to add labour and bearings etc.

Anyone have experience with getting hold of a second hand diff head and replacing your existing one. Do you think it's too risky to buy second hand? What about the sawdust or banana trick. Is this for real or just an urban myth???

i have brought a few diffs/diffheads and never had a problem.

You can pick up a terrano diffhead for about $200, much easier than having to replace all the bearings etc, best of all you can do it at home with couple of jackstands and a good socket set.

i would offer you one of mine, but the one i have is for spare.

Dirtydog wrote:i have brought a few diffs/diffheads and never had a problem.

You can pick up a terrano diffhead for about $200, much easier than having to replace all the bearings etc, best of all you can do it at home with couple of jackstands and a good socket set.

i would offer you one of mine, but the one i have is for spare.

Thanks for the info Dirtydog, sure is good to know there is a relatively cheap fix. Cheers!!