Seems to be happening more lately and had happened in the past....haven't noticed it again until a couple days ago. It seems that if I'm driving with slow accelerations like in afterwork traffic, the first to second transition gives out a quite noticeable jerk. Anyone know how I might diagnose?

If indeed this is a tc or gearbox issue, can someone point me in the best direction to buy complete rebuilds of either? I don't plan on letting go of this car ever and would rather replace with like new if I end up needing to go to a full replacement of any kind.

Thanks!

 

Dan,

Assuming USA, and a 4ltr with the electronic transmission?.

I would do a simple fluid change. It has a dipstick, so undoing that large nut, let it drain, and then refill, will suffice initially. I use Synthetic Trans Fluid, and my X300 is now as smooth as any I have ever owned. It was "lurchy" (if thats a word) some time back. I have done 7 of these drain and refills on this car in 4 years, and it got better each time I did it. Bear in mind mine is the same trans, BUT, the NON electric version, as it has a kickdown cable coz its a 3.2ltr which the USA never got. It now 207k kms and gear changes are barely felt.

Of course it may be something in the electronic control circuits.

These transmissions are TUFF, and failure of these is rare when compared with the newer sealed units.

 

I have followed Grant's multiple-part-ATF change regime.
I also have a 3.2 with no electrics to the ZF gearbox.
I have done about 5 part-changes now in 6 months, each time about 3 - 3.5 litres. It is way smoother but not perfect - a little jolty under power when changing up from 3rd to 4th, but otherwise 95% better than 6 months ago...

 

Would a all-out flush get better results (quicker even)?

 

Yes.


But the DIY drain-then-refill is so easy and cheap and the results are as good, or nearly as good, as a professional flush job . Nowadays most shops are charging $150-$200 for a real flush-out.

You can speed up the results by simply repeating the process with a few miles driving in bewtween. Make an afternoon of it!

There is some worry about using the pressurized flushing equipment stirring up muck and creating problems. I CAN happen, but in my experience, very rarely. If there's that much muck to be stirred up then the trans probably isn't long for the world to begin with.

Cheers
DD

 

Sidebar: I believe I have Dexron III in the transmission. Can I do the partial DIY refill process with a syn transmission fluid or does that require a full flush/fill?

 

Down here the Syn ATF is compatible with any Mineral ATF, and vice versa.

With a 10L capacity, and about 4L each drop and refill, it takes about 8 to get the concentration up in the high 90%. I had a chart somewhere, but it is hiding, maybe on the dead computer??. It was from BMW a very long time ago.

 

I know exactly what you are talking about. My XJS which has the exact drive train as your X300 has been doing it intermittrntly for years and I have changed that fluid and filter out more than once.

I suspect the problem is either with the transmission ECU or some sensor. I don't know if the throttle cable could be causing this or not.

 

FWIW, I practice Grant's xmsn drain/refill with DEX/MERC mineral at all "fair-weather" oil changes. (I don't bother when it is biting cold) Acquired the car with 63k mi on it and shifts were smooth then, smooth now at 139k. If I want to feel a jerky xmsn, I can always take one of the S-Types out for a spin....

 

Grant, I'm not sure the ZF 4 speed holds 10 litres. It seems hard to pin that capacity down - however one ZF source I found on the net a few months ago said 7 litres.
I usually get 3 1/2 litres out per drain.

I am lucky - my gearbox has a 6mm Allen key drain plug. I don't have to remove the dipstick nut. I couldn't anyway - I got my 12" Crescent on it and it wouldn't budge.
I think Grant's has no drain plug - go figure..

 

Yep, NO drain plug, real poverty pack Jaguar.

One day I will find a pan with a drain, and steal it.

The 10ltrs was an estimation, coz actual "dry fill" is always a scetchy quantity. I know my TH400 was near 15 when I had it refreshed, including the bearings inside the convertor, and that has a much larger convertor that the ZF.

 

I guess I didn't read grant close enough...I have a drain plug...wouldn't want anyone to credit me with more work than I'm actually doing! I usually get about 3 qts or so.