Hi, long time lurker and finally dove in to ask a question. I'm not new to Land Rovers, I'm on my third...apparently I don't learn lesson well

05 LR3, HD 180k on clock. So far I have replaced all hoses, belts, radiator, fluids (trans, diff's, t-case, H2o), rotors/breaks, and plugs. I'm at a baseline for the most part.

The PO said it needs a rear diff when I purchased, local indie shop that has worked on it for over 10 years says needs rear diif. They replaced the locker motor in hopes it would "fix" the problem and was the cheaper solution, but it didn't. The local indie shop is NOT the one I used for my previous builds, and when I went there and asked about previous records he pointed to boxes in a back room and said probably back there somewhere. The PO, stand up guy and honest, said he would just take it to the shop when something didn't work. This was a kid hauler and grocery getter for most of its life. The PO didn't even know it was an HD.

It currently shows "transmission fault limited traction" every time I start it. I was recently going up a few freeway hills, long, not a pass or grade, but good length. When going up the first hill it increasingly slowed to about 50 mph and wouldn't shift down even though I had it to the floor. On the second hill it did the same thing but got even slower and when I exited the freeway it went into limp mode. I pulled over turned off and back on all was fine.

Checked with PO who said when it happened to him it was "like gears slipping".

The codes my mechanic buddy pulled said something about 5th gear, all the trans temps showed in normal range when code flashed...he says its the trans but he isn't a rover mech, a great European mech but not specifically rover and couldn't understand a trans code fault if it was the rear diff and the local indie says rear diff will give a trans fault and rear diff needs replaced.

So, who is right?

 

I wouldn’t want to guess since I am far away but perhaps this handy ZF troubleshooting guide will help you figure out the issue. In general, however, I’d say that the problem is in the transmission if you have gear slips.

 

A diff will get noisy before it fails and since it has a code for 5th gear (i expect its P0735 or similar) it would be a trans issue, a good euro specialist should be familiar with the ZFHP26 auto.
I would check the trans fluid level again but since you already changed the fluid it may not be the issue.

 

Thank you for the guide.

 

There is zero noise coming from the rear diff. My buddy, who has his own shop and is trained European mech, from Europe, is holding to its a trans issue and not rear diff. He is extremely familiar with the ZF.

He is the one that did the trans pan swap and even double checked the fluid levels when I brought it back to him, stating that’s usually the culprit.

Thanks for the info.