TD5 Gearbox

Hi Guys,

New to this so hope I do all of the right things.

I have a 2004 TD5 Discovery, diesal and automatic. My wife and I just completed a 6000km trip around Western Australia towing a 2.5 tonne caravan. Had the gearbox checked before we left, all well until just before heading home the landy started revving out in first gear without the caravan on. The change to second would not occur until about 4500 revs and was naturally lumpy, however subsequent changes to third etc. were fine. This problem was intermittent, and only in first gear, with or without the van hooked on.
Arrived home, booked it in to a mechanic who said the oil was very brown but their computer said there was nothing wrong. Took it to Adelaide to a landrover dealer who changed the oil again, plus filters but who also said there was nothing wrong. There fix was a new gear box!!!

The weird aspect of this is the fact that like today I drove it to the shops and it did the same initially but then was fine. Surely if the gearbox was faulty the problem would be continuous..........could it be the computer? as I am loathe to go ahead with a new gearbox apart from the cost, without getting some expert opinions. I am happy to fill anyone in on other details I may have missed, but would really appreciate some help. Thanks Brian

It could be the governer in the box is sticking. Get the governer removed and cleaned.

Thankyou Andy,

You could well be right but it is getting those who are supposed to know to look further. Since posting more weird things have been happening...i.e. 1. the brake lights suddenly stay on and the only way to get them off is to remove the battery terminals, or 2. it will not go in reverse..........again with the same fix. Thankyou Andy for replying, I did not think anyone would. Does the latter help in diagnosing the problem, my gut still says computer, but I am the only one. Did find a loose nut coming from the gearbox with the wiring running through. This was tightened and connections checked but to no avail. Thanks again

Fellow Oz Disco driver, my suggestion is that there is something loose or chafed in the electricals. I have experienced a chafed wire loom to the auto gear box, with bad results. Before disembowelling the gear box get the loom checked for continuity.
Winjeel

Yes I agree with winjeel (?), it sounds like some bad wiring somewhere.

If you have the chance, get underneath and tried to find any wires that are chaffed and shorting out. Also check the locations of all the earths and clean them up.

All sorts of lecky problems are caused by bad earths.

Thankyou both. At last someone agrees..... today the disco would not turn off. I find it hard to believe that Landrover specialists either are not listening to me or are so one tracked that their only fix is to rip the gearbox out. Thank goodness for forums like this.
I am booking it in to an auto transmission guy who specialises in electrical problems and see how we go. Will let you know as it may help someone else. Cheers Brian

They're not called 'Land Rover Main Stealers' for nothing!

If it is an electrical loom problem, replacements are available from British Motor Imports, who bring Land Rover parts into Australia. Very reliable operation.
Winjeel.

No joy these guys said all was well.....their fix is to get a new computer!! Costing me a fortune in fuel and mechanics bills with still no diagnosis, could have nearly replaced the gearbox by now. Too frustrated at the moment to think about it, nothing is getting worse so I will keep driving it until I come up with something new. Thanks anyway Brian

The ZF box has its own ECU by memory, and it would be worth checking round the box, the ECU itself and any sensors that feed road speed etc into the ECU. A bad earth point would also play havoc, check engine bay earths on the battery side, and elsewhere. I don't know without checking if the ECU has a point close to it or not.

Gearbox ECU's come up on Fleabay, the 2004 is the last Disco 2 year so you'll need to check part numbers if you buy secondhand, but that's what I would do. Even with shipping from the UK by registered Post it will come home at under $AU200 or so.

The ECU is under the passenger side seat. Have you got the RAVE CD?

Peter

Download the Rave manwell if you havent already- they normally show earthing points, location of ECU and fault finding. Link is in the Qs and As bit.

Thankyou both for the info on the Rave CD, took all day or so it seemed to download but what an asset for Disco owners. Now I have a task infront of me just reading the manual, I am not that techno but I am going to give it my best shot. The ECU is actually under the DVD player that is also under the passengers seat so I have bought a tool to get the seat completely out which will hopefully expediate matters.
Greatly appreciate all the input, just fantastic. Brian

Ok cleaned all the earthing points on the ECU and touch wood all going well. Until next time thankyou sincerely for all of you who put me on the right track and literally saved me hundreds of dollars. Fantastic forum, pity the world wasn't smaller. Brain