I'm sure this must be gearbox, but what to do?
 

I've been getting the odd "thump" for ages now (years) and it sort of feels like the box "might" be changing gear then not rather quickly.
It's usually been associated with steep hills and corners so I'd also vaguely wondered if it was ESP-related in some odd way.

Anyway it was a bit more noticeable yesterday (and I wanted to have another "play" with the dodgy cruise control too) so I decided to go for a little "test drive" today in the snooker mid-session interval.

The cruise control did work normally the first time I tried it (until I braked), after that it wouldn't engage any more. :(

Back to the box.................
I tried driving in manual mode for quite a while, so that the only "automatic" changes would be down due to kickdown or slowing down. This is a PF system so no separate kickdown switch, so the kickdown mechanism (whatever it is) "could" be part of the problem.
I couldn't get it to thump or judder consistently, but it did happen several times. No "precise" pattern, but the following observations from today and before:
1. It definitely happens in 3rd gear, and quite likely in 2nd too (not really there long enough with my foot down! or 1st!! :rolleyes: ) but not in 4th or 5th.
2. Sometimes it's just one thump, others it a judder of maybe 3 or 4 max over maybe a second or a tad more.
3. Engine revs just seem to rise normally but there is the feeling of a brief loss of power. Again I have wondered if the ESP is doing something at times.
4. The problem appears "typically" (but not definitely) going up a steepish hill in 3rd gear at 3000 revs or less. More often on a bend, but they're often the steepest bits anyway.
5. Kickdown works normally when I floor the pedal in typical situations, including from 4 to 3 and 3 to 2.
6. It probably has spent 99% of it's life in top (occasionally 4th) gear, being used almost exclusively on long journeys; no commuting or shopping trips!

So, any thoughts anyone both on what it is and what to do?
e.g. Time for a gearbox fluid and filter change?
(it's done over 120,000 miles and had no work as far as I know)
And if so, is there anyone trustworthy not too far from me - I'm near M40/M25?

Could be a faulty brake light switch

I'll be honest, from having looked inside one, it could be a number of things but all are internal and not easy to get to without having the transmission out of the car.

I would try talking to Chester Transmissions or any other good ZF Transmission specialist and describe the symptoms.

It sounds like a drum/unit moving forwards and backwards inside the gearbox but could just as easily be a sticking solenoid...

Have you plugged in and had a look for any error codes from the transmission?

MG

Not recently, but I will probably this weekend.
Last time I did (few months back) there was nothing significant and it's been doing this on and off for years.

I do know that the previous owner, long long ago, had a chip replaced. He told me it varied the gear change speeds holding them longer for brisker mid-range acceleration (!). I wonder if that might be related?

I have an old receipt which just says "Supply program and install Superchip" plus 44-pin SMT nasp protection board and Eprom. No spec as to the actual changes.
I also have the removed chip which has a Bosch label. Looks like it was a soldering job.

Sounds like gearbox on the way out :( As said speak to Chester auto
http://www.transcentre.co.uk/
They know their way around a zf gearbox .....they have repaired mine!!!!:p

Thanks, I will.
Unless anyone can recommend somewhere a bit nearer to me... (M25/M40 intersection is not far) ;)

nearest ZF approved agent to you is -

Vanmatic Ltd
1 Viveash Close
Hayes
Middlesex
UB3 4RY
United Kingdom
Telephone: 0208 848 9911
www.vmtp.com

There's also -

Alliance Automatic Company
3 The Pilton Estate
Pitlake
West Croydon, CR0 3RY
Tel: 0208 680 6802
Fax: 0208 686 3381

I looked at the Vanmatic site a while back and sort of got the impression they were a parts supplier. :Confused:

I'm (probably) going to need someone who can take the box out and service or replace it (presumably with a reconditioned one).

^^^ I could certainly yank your trans, I can't service it though. Still, you could ship it to a ZF specialist.

I found this thread fascinating: http://forum.a8parts.co.uk/showthread.php?t=4452

I don't have the skills or tools to go anywhere near that, but appreciate how simple the actual problem was, unlike getting to it!

Whereabouts are you Nollywood?