Hi, First of all just wanted to say thanks as I've relied on help from these forum pages for a number of years - but never needed to post.

I have an issue with the gearbox in our 2003 TD6 Range Rover. The box was reconditioned approx 10k miles ago and has been faultless until yesterday! From cold(ish), the gearbox changes smoothly upto around 30ish mph - and then the revs build past the point where you expect it to change - and then you get the 'dong' and the trans fail safe message. The car then seems to lock in third - I'm pretty sure its not 4th - but maybe it is. All the while, it is smooth with no bumps/jolts/bangs.

I have used All Comms to read the error codes - and this is the weird bit - no codes get generated. Nothing in the Gearbox ECU - or the Transfer Box ECU. I then tried leaving the laptop connected and reading the codes live - same thing, nothing recorded - just the message.

The only other test I've done is check it stills goes into High & Low box, which it does fine.

I've spent hours going through the forum searches and I can't find anyone with these symptoms. Has anyone seen this before, or would like to send suggestions? Any help would be gratefully received. I've spent a fortune on this car, and really don't want to see it go - but can't face putting another gearbox in it so soon!

Thanks in advance!

Hi. Sounds like bands and or clutches or valves issues - is there a Mr Gearbox type indy near you? Their diagnostics will find it. Cold snaps , in my experience, throw up gearbox issues so it might not be much. ----------------
2010 RR tdv8 3.6 ( gone but not forgotten ...)
2012 RR tdv8 4.4
2004 RR 4.4 V8 (M62) -gone but not forgotten (sob)
1998 P38 RR - least said the better
2009 BMW 7 Series 3.0d
Various motor cycles - BMW GS
1998 Jag XKr 4.0 V8

I've done a little more research, and unfortunately its looking like I need another gearbox. A bit disappointing as this one has only done maximum 10k miles.

Again, I have searched through the forum and can't find anything, but has anyone on here ever tried rebuilding a box themselves? I can see the very experienced RRPhil has made some fantastically informative posts - I just wondered if using the advice on here if anyone had been brave and tried it? And also where would you source the internals from?

I will happily document my experience as I go if i'm to be the first!!

Hi, as it is a cold engine, I would look at the internal wiring loom after checking the box has the correct amount of oil in it, and the oil is not leaking into the Transfer Box. There is a Temperature Sensor inside the gearbox built into the loom. It sounds like the Lock Up clutch valve is not latching. It is a General motors box, so look on American sites for rebuild information and parts kits. I have seen repairs offered for £1200 upwards. I usually fill the box with Dexron three oil.

Could be the usual direct clutch hub shaft failure : https://www.fullfatrr.com/forum/post550029.html#550029

I don’t think that I ever put my GM 5L40-E teardown thread on this forum, and I’m not sure if I’m allowed to point to another forum? If I am, it’s here:

https://xoutpost.com/bmw-sav-forums/x5-e53...rdown.html

If not, I could post it on here, if it would help.

Phil

I rebuilt it, if you have any questions just ask me

Thank you to everyone who answered. Unfortunately I stopped getting notifications, so had no idea of the replies.

I have subsequently used RRPhils brilliant write up to take on rebuilding the box. It is indeed the direct clutch hub that has failed- for a second time. The company that rebuilt the box for me 10k miles ago fitted a second hand item as they couldn't source a new one at that time.

I have started a new thread with a question on the correct clutch hub size (ie 191mm or 194mm long).