Hello all

On Monday I drove for a couple of hours in the worst rain ive ever encountered, followed by driving through some deepish water (30 - 45cm I would guess).
Following this, I developed the classic rear judder on any steering lock under 10 mph. OK in a straight line.

I have today changed the oils in the rear diff and the transfer case hoping this would solve matters, but unfortunately it has made no difference at all.

Does anybody have any suggestions please?

Many thanks


Neil.

Did you re-calibrate the transfer box ? It needs to re-learn the clutch position when new fluid goes in.

Is it a locking rear diff ? could the electrics be flooded on it ? V8 or else ...

If a locking rear diff is fitted then did you use the correct oil?

I used what the dealer sold me. ie DTF-1 for the transfer box 1.5 litres and .82 litres of SAF-X0 TYK500010 in the diff with new washers and plugs.

I haven't recalibrated it, is this a dealer job, or I wonder if I can do it with my Foxwell NT530 which has LR software loaded?

I did wonder about any water damaged electrics as its a bit of a coincidence, where should I be looking for this?
Sorry if this is a dumb question but im only a keen DIYer!

Cheers

That diff oil is for an open diff so if you don't know if an e-diff is fitted then you should determine if your vehicle does or does not have an e-diff. This can be done either by inspecting the diff itself or by selecting rock-crawl, transmission in D and with the steering wheel straight ahead which should show either red(locked) or green(open) for the rear diff on the 4x4 display.

Hi

Just checked and the dash and it lit green so looks like I have the open diff, so oil sounds Ok.
Looks like some water into something electrical then, any suggestions where to look please?

Many thanks

How did the old transfer case oil look? If particularly dirty then a double flush and calibrate is the usual fix, with the wading and juddering perhaps coincidental. Recalibration isn't required with a regular oil change but if it hasn't been changed for a long time or the wrong oil was used previously then calibration will be required.

The oil wasn't bad, it was last changed in Feb 2020 around 50k miles ago at an independent.

I change mine every 40K kms so twice as frequently, but it does get a work-out in sloppy conditions every time there's rain.

Managed to plug the OBD tester in today and read the code "P08A-54 clutch position not learnt" on the TCCM module.

Tried to update it but got the message "ECU not support" so I guess a more sophisticated tool is required...

Off to the Indy it is!

Thanks for the help to date.
Cheers
Neil.

It's a pity that as the control module knows that calibration is required that it doesn't just calibrate the next time the ignition is turned off, as the diagnostic tool simply commands the module to perform its calibration. Anyway, at least there is a code to follow-up.