Hello everyone! I'm new to the site and I must say you guys are awesome. I have been lurking for some time now just checking out reviews, tuning adventures etc. Unfortunately for me I am looking for some help with a Gearbox fault that I keep getting in my 2004 stype 4.2. So here's the scoop, in D the car will lurch a few times, then it will give a gearbox fault and switch to one gear. I have to pull over, turn the car off and on. The gearbox fault disappears and the car drives like normal. This happened off and on for a few months, maybe once or twice every few weeks. Recently this is happening every day, several times a day. When I drive it in manual mode the car runs like a dream. Smooth, powerful, awesome. but when i switch back to D i get the same darn gearbox fault. I've done some research and learned that I should check two things first, the battery, which i have done. And the trans pan, filter and gasket. I am about to replace the pan, filter and gasket and load it up with some fresh trans fluid (Jag Synthetic Fluid). Hopefully that resolves the gear box fault. However, before doing this I thought I could ask for your collective expertise.

1) Is this gearbox fault a common issue?
2) do my symptoms sound mechanical or electrical?
3) do you think replacing the pan/filter/gasket will resolve my issue?
4) are there cheaper options for trans fluid than the $46 jag synthetic?
5) are there cheaper options for pan other than the $246.60 OEM from dealer?
6) for some reason, my 2004 seems to have a 2005 model trans pan. I dont know why but it does.

Thanks all! Any advice is welcomed!

 

Well you’re missing the most important thing to do??

Get the codes before you touch your car. Then get them erased and make sure you have the same repeatable codes coming back.

Next research those codes to see what others have done to fix it. Finally make your plans on what to attack first.

No problem with servicing the transmission but if you need a new TQ I would not change fluid before.

You do list the year and model but left out how many miles are on the car and has anything ever been done to the transmission??

You might have something simple like low fluid level.
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+1 to third6

Just out of curiosity how did you check the battery?

 

It has 85k miles, never had any work done on the trans. never had fluid or pan changed. Bought a new battery from autozone last year, took it in last week to test the charge, they told me voltage was fine, carried a charge and basically said it was working fine.

Great idea on the codes. So do you recommend I write down the codes first and then clear them? Or clear them and wait for check engine light to come on to see what is initial error. I imagine that I have a lot of codes showing now since I've been dealing with this for a few weeks now. also, other than taking the car to the dealer, is there any other way to check and clear codes myself? Dealer charges a pretty penny just to do a diagnostic.

 

Argh, I've been researching how to solve this problem for far too long. Anyone know a credible Jag mechanic they recommend?

 

You can buy a code reader for about $10 online something like an elm, also I belive auto zone and the likes will read codes for free? I'm in UK so not sure