Jatco auto box - reverse

Hi all, i'm after some advice on how to deal with an issue with my autobox.

While greenlaning this weekend, i selected reverse, got a small slight clunk, and the engine would rev as if it were in neutral. No reverse drive at all. I had F4 on the dash display for a second but it cleared and never came back. It drive fine forward, properly selects and displays all gears, including reverse, but when selecting reverse, despite feeling the box engage and do something, no reverse drive.

I have not touched the autobox recently, so dont think it can be the reverse bolt that occasinally gets taken out by mistake.

What would be the best way to check whats up, low on cash atm so appreciate any ideas or tips.

I'm thinking:

Check barrel connectors (maybe disconnect battery for a while)
Then solenoids? Not sure how to but willing to try.
Check reverse bolt
Give up and take to service.

Thanks.

are the barrell connectors tight, clean, waterlogged etc.?

Checked barrel connectors this morning, they seem fine, properly seated, dry, clean. Tried disconnecting battery, same thing.

Anyone have any other ideas to try or experience to share?

Is the 'belt bolt' which many people think is the oil filler one but holds the reverse bands in place, still there?

Search for hippo photo if not sure which one in thread changing oil in Jatco 'box.

definitely dont take bolt out to check , is oil blackish or contaminated

Haven't been able to lift it to get under - will check bolt, just never heard of it coming loose by itself.

Good idea with the oil - will check it - could oil mean a lost reverse gear?

Same thing happened to me, everything OK except no reverse. Reverse band had gone cost me £1450 plus vat for fix with two year warranty.

I used Gravesend Auto repairs. Excellent service

just for a reverse band replacement?

That is what they told me it needed. They also replaced the torque converter checked everything else, new oil etc.

I had it done Feb this year and no problems at all since. What would you expect it to cost? This was not the cheapest or dearest but did have the best no quibble warranty.

very little just to change rev band, a very simple job

jamesmartin said:

very little just to change rev band, a very simple job

Click to expand...

But a gearbox out job?

How many hours?

I have been quoted £1780+ vat for a gearbox & torque converter rebuild. New solenoids etc and fitting. Would take 4 days.

Not cheap.

Ashcroft charge £1500 approx for a recon 'box fitted same day.

yes box out as you need top pull front housing off , about 1/2 an hour to change rev band , a rebuild is a different job as cost depends on what new parts you fit ,but its not a difficult box to build

Is this a common problem for jatco boxes?
Ive got a td4 auto and went down a few lanes earlier and after i parked up i got an 'F' on the display instead of 'P'.

OK, got a result - found a good gearbox specialist here in the Czech Republic (good reputation on local forums e.t.c).

He took the gearbox apart, found out the brakeband had broken, so will be replaced and all will be well. While he had the box apart he checked whether any other parts looked worn or like they might be nearing end of life - his verdict was that it's in very good shape.

Strangely enough when i was discussing the box with him, he mentioned he fills the box cold, that he's never had a problem doing it that way. His view is that doing it that way will only result in a max of 0.01l extra fluid going in, which he says would not cause a problem.

Also, he uses the right spec oil, but not from the dealer (says he goes by gearbox manufacturer specs).

The cost seems reasonable - all work including parts 14,500CZK - about 400 pounds.

Wow bargain!

DefUnct said:

...Strangely enough when i was discussing the box with him, he mentioned he fills the box cold, that he's never had a problem doing it that way. His view is that doing it that way will only result in a max of 0.01l extra fluid going in, which he says would not cause a problem...

Click to expand...

I'm sorry I don't agree with this. I appreciate the chap may specialise in auto's. But far too many people come on here or pm me with Jatco auto filling problems. It's all over the web. Not following the correct procedure as listed on here has caught out many owners. Either themselves doing the job wrong or worse still paying someone else to do it wrong. Anyone not following the correct procedure does so with a massive risk. It's too much of a risk for people to take in my opinion.

The correct fill level is set with the engine running, at the correct temp as per the instructions. When the engine is running the pump sends auto oil around the auto, which is why the level drops to the top of the level tube. When the engine is off the auto oil level rises way above the top of the level tube. Level tube at the bottom of the auto in the pic below. Anyone not reading/following the correct instructions is taking a massive risk.


DSCN3006 efOJNsR

Thanks Hippo - I'm aware of all that has been written regarding this on the forums.

Although surprised by what he said, to be honest i didn't really argue with him, since I'm used to things being done a little differently over here, but the result is usually good. Having got the call that it's ready to pick up, it's probably too late to influence this - do you have any recommendations on how to proceed? i.e take it for a drive on way home and check level or something similar?

A short drive...

So, got the car back this morning - had a chat with the guy that did the work - he doesn't warm the engine up to temp before filling, but always fills with the gearbox with oil whilst engine is running (he explained it the same way as you Hippo). Drove to work, smooth gear changes, all seems well - very pleased.

Also, although he said he puts the right oil in as per gearbox specs, though not from dealer - is there any way i can check? (ie theoretically since this box is in more cars, he could put some Jag gearbox oil or something in thinking it's ok, which isn't correct right?) What would i notice with incorrect oil?

As long as it is the correct spec it doesn't have to be from the dealer.