Thread: Thicker rear diff crown wheel on T/C puma?

I agree...and ive had 3 rear diffs!

Ive also heard in the past that that bolts are bigger in the P38, whether this is true or not im not sure. I honestly believe these diffs are a "setup issue"....

I thought I would ask this question as it is closely related to your discussion. My Defender 110 (2012 model with 80K on the clock) gets a whirring noise at around 80km hour in the back of the car and this goes when you get past 90+Km hour. It is now off warranty and I have taken it to a local mechanic (recommended by locals with Defenders). He (the mechanic) though it was the left hand back wheel bearings and these have been replaced. But this did not solve the issue. I suspect it is the diff. Has anyone experienced this before?


Happy for some input. Cheers! Brad

Originally Posted by Brad H

I thought I would ask this question as it is closely related to your discussion. My Defender 110 (2012 model with 80K on the clock) gets a whirring noise at around 80km hour in the back of the car and this goes when you get past 90+Km hour. It is now off warranty and I have taken it to a local mechanic (recommended by locals with Defenders). He (the mechanic) though it was the left hand back wheel bearings and these have been replaced. But this did not solve the issue. I suspect it is the diff. Has anyone experienced this before?


Happy for some input. Cheers! Brad

Does it make the same noise or worse when your foot is off the throttle?
If yes its more than likely the diff.

It might not be the diff, on other varients I've had similar noises turn out to be

the backing plate on the handbrake scuffing and ringing at certain speeds and it sounds like its coming from down the back.

a brake backing plate vibrating in harmony with an out of balance wheel.



if you can modulate the noise by applying and backing off power while maintaining speed it might be the pinion nut starting to come loose and the mesh is just starting to go a little out.

I have exactly the same thing in my 2013 110. Like a whine from the rear.

First was between 80-90, but now also sometimes around 30. Also seems worse when towing.

Can't modulate it by power up / down but can get rid of it by moving out of those speed ranges.

Dealer in Townsville reckoned rear diff and keep an eye on it (I was passing through). Now back in Sydney and have asked local dealer to look at it (warranty) as it's getting worse.

Simon

check the pinion for free play, if you can poke it in and out or wiggle it round thats a pointer to the problem.

as a short test its worth pulling the rear shaft and taking it for a very short drive (fully unloaded) with the CDL locked see what that does for the noise. Make sure you mount the handbrake drum properly or remove it.


it might also be the carrier bearings letting the crown wheel shift sideways, but Ive only ever seen one diff do that without lots of metal in the diff oil.

I wish I had the knowledge to follow your advice.

As a lad I had no interest in learning mechanics, not even an oil change. Something that is a regret to me in later life when I have the interest but not the knowledge

Simon

Hi Guys, Some interesting comments. To answer some of the questions in the post. The whirling starts at about 80k and stops as you increase speed and visa versa. If you back of the throttle quickly is stops immediately but there is no clunking from the diff. As you increase speed again the whirling kicks in at 80K. I have done this repeatedly and no real clunking from drivetrain. The local mechanic I use is experienced with Defenders but he is unsure what it could be. I don't want to spend a fortune on trying to guess what it might be.


I will get him to look at the ideas you have come up with. Keep you posted.


Thanks for your help!


Brad