OK, so about 3 to 4 weeks ago I noticed that the dreaded lurch (zf box) was getting really bad, and that at 30 to 40mph during warmup (between 1/4 and 1/2 on the temp dial) the car would be almost hesitating whilst driving. I initially wondered if I was getting misfires as that is kind of what it felt like. When this would occur I could also hear a strange noise, hard to describe but quite low pitched and rumbly as if driving the car over a rumble strip.

This noise would also be present under load going up hills on the motorway at 60 to 70mph.

So, given the car has just hit 100K miles and is now 10 years old I decided to get my local Indy Jag workshop to do the oil.

They replaced the oil and updated the gearbox to the latest software.

The gearbox does seem smoother, but this behaviour of the car hunting between gears at 30 to 40mph has gotten much more noticeable and much worse, even persisting after the car has come fully up to temperature.

The Indy has said that this behaviour has been noted by Jag, but only on XK8 models and can be fixed with a coded access? software patch to the gearbox. They've never heard of it affecting an S-Type. They contacted Jag about it last tuesday yet to date there has been no reply at all.

Has anyone else come across this type of problem on the ZF before?

 

Oh yes, forgot to add, zero stored codes for engine or gearbox....

 

That sounds to me like a torque converter heading south. Search on here. Plenty of threads about it.

Take care,

George

 

ive said the same on the uk forum

 

try contacting Mackie Transmissions in Glasgow.....0141 778 4545

They fully service & refurbish ZF transmissions for many marques / dealers as well as private individuals, I was there today.

They also refurbish and supply torque converters from inhouse works.

Why not call them and ask for advice?

Tell them you are a member of this forum.

 

Thanks Jim, will do. I like Glasgow, drove up there last August to play in the World Pipe Band championships....

OK, the problem is weird. I basically do the exact same drive every day to work and back, 40 miles or so in total, and the same drive at lunch up to the shops and back, maybe 5 miles.

Yesterday, morning drive in, absolutely terrible, hunting all over the place. lunchtime, really bad, lurching between shifts and really misbehaving. Drive home, slight anomolies whilst warming up, then not a single problem.

Today, slight lurching for the first 10 miles or so, even at operating temperature, then fine. lunchtime just now, no issues.

I got the Halfords people to whack their battery tester on the battery, it passed OK allthough reported it as a good battery that needs a charge. Charging system came up as OK. stupidly I forgot to ask what voltages came up. doh.

It might very well be the original battery, it has a Jaguar logo on it. I've had the car 14 or 15 months now.

Whilst looking at the battery I also discovered significant water collected in the spare wheel well, the connecters for the module on the left hand side are resting in water and are soaked, not sure what that module does......

 

see here for water in boot JagRepair.com - Jaguar Repair Information Resource

 

Bingo! Take care of this immediately before one of the computers becomes fried. There a rubber plug on the floor that can be removed to drain the area.

 

Just had it confirmed, coolant in the gearbox :-(

 

I thought that only happened to the diesels

 

Oh, sorry to hear that, can you tell us more?

 

Well, they had a look at the ATF, which has only been in there for almost a month, and it was completely emulsified
So, they're getting the box reconditioned, fitting a new radiator and cooling lines, all for £3k
*sigh*
*ouch*

 

Wow.....that is an ouch!!

Just outta curiosity, who's doing the work for you??

 

Kings in Berkhamsted, I'm pretty happy with them they do good work the times Ive got them to do stuff instead of doing it myself

 

Ask them who's reconditioning the box for you?

Its likely to be at a guess either Bristol Transmissions or Mackies Transmissions.

They'll be about at least half for the reconditioning side, but I guess its all about just getting it done / taken care of etc etc.

I'll keep my fingrs crosses that all goes well and that they come back and shave a few £££ off the price for you.

All my best

Jim