Jump to content

Replacement Front Differential

Recommended Posts

For the first time ever I have manged to destroy the front diff on my 90. It happened while out green laining and driving gently.

I have done a number of pay and play days but not for a couple of years now.

It's a 1986 90 with standard Discovery 300Tdi fitted.

The front diff came from a V8 range rover (due to the original one having play in the pinion bearings) so it probably had a few miles on it when I fitted it.

I'd say that generally I have a light right foot except for the odd occasion when I've really tried to climb various slopes.

It's probably a common failure. The shaft/pin that the pinion gears mount on has worn and finally snapped.



Reading the Ashcroft web site it says that the rover diff does suffer from the pinion gears friction welding to the pin and then breaking. This may be similar but the pinion gears are certainly not welded to the pin.

In terms for a replacement there is a company local enough to me that will rebuild the old original diff. However, I also have a 10 spline ARB locker (RD03?) that I bought second hand in the shed that I never fitted (another story).

I'm tempted to fit the ARB as I believe it is stronger than the standard diff but I'd prefer to have it checked before it is fitted correctly (it is fitted but the carrier bearings are lose). The last time I checked it locked and unlocked ok but needed new o-rings as they leaked air occasionally when the crown wheel rotated.

Unfortunately the local company are not keen on dismantling the ARB unit but are happy to fit it into a diff.

The last time I considered having it checked I spoke to Steve at Crown Diffs but I understand he no longer provides this service.

The questions I have are:

1. It is still; possible to get spares for the RD03? (I haven't tried exhaustively but a few searches on google fails to find the o-rings)

2. Does anyone know who could check the ARB locker?

I am aware of Ashcroft but they always seemed to be more expensive than Crown Diffs.

3. Is it possible to dismantle it yourself?

4. With regards to the failure is this inevitable from pay and play days or just my failure to change the diff oil often enough?

Finally, I know there is someone else on this forum who generally suffers an injury and in no way am I trying to steal their crown but, why is blood always involved when working on a Landrover?

Just when I though I'd got away with without being cut, scraped, gouged etc the old front diff got me after taking it out of the shed:


At the moment I'm 50:50 between fitting a standard diff and hoping it doesn't suffer the same fate and fitting the ARB unit and hoping it is ok.

Any help is most appreciated.



  • Like 1
Link to comment
Share on other sites

As far as I know parts are still available for the 10 spline ARB diffs - try Devon 4x4 and Ashcroft for parts. If it leaked before being stored the chances are it will still leak now. I think the seals are X section but may be someone else will confirm it. I have a 10 spline ARB also which I cannot sell, which I am sure was fitted with X section seals when it was overhauled by Steve at Crown as they were supposed to be better. The plastic cage inside quite often fails to so when you get it in bits (if you do!) then replace this to. Ashcroft used to do an uprated steel one but not sure if they still do or not.

Try Nige (Hybrid from Hell) on here, he will tell you all you need to know and can rebuild them to!


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy