About the car I bought in this thread, here's a question about the autobox (ZF 4HP22 all mechanical):

gear changing goes smooth from 1 => 2nd, and is noticibly a hard snap at about 40-50 mph (2nd to 3rd ?).

I will start by changing the oil and checking the filter in the pan, and will check for any mechanical causes (like the rubber blocks at the engine mounts, and the coupling at the driveshaft.

This is the first time I've driven an autobox, so I don't really know anything about them. Any pointers? When I drive carefully, and let go of the throttle at the time of the gear change, it goes very smooth and barefully noticeable. When I don't pay attention, it's really unconfortable. Other gear changes are very smooth, it's just when I ease off the gas pedal after it has changed gear.

 

Trans fluid is waaaaaay past its ude by date.

I suggest dropping the old fluid, either by the drain plug IF one is fitted, or simply undo the large flare nut on the dpstick tube and let it drain out.

Refill with fresh (I use Full Synthetic), and drive it about 100KMS, drain and refill again. Keep doing this until the colour of the draining fluid is about the same as the new fluid.

The filter inside is a Brass Mesh thing, and changing it is not required.

Mine took 5 drop and refills to get the colour close, and I noticed the trans smooth out after 2, and got better at each doing, and now you really have to watch the tacho to know its changed up or down, soooooooo smooth.

 

Thanks, that's good news.
Already bought enough for 4 or 5 partial flushes.
I've bought Dexron III ATF, as specified by both jaguar and ZF.
I'll keep you updated!

 

Didn't have a lot of time lately, however I managed to drive another few 100 km's with the jag.
In the meantime, fluid has been changed 4 times, oil comes out now nice and red.
However, the snap/jerk still is there, and I don't really think it has smoothed out with the flushes.

Will drop the pan now, to clean the filter (and the magnets, if it's a pan with these built in). What do I need? Gasket? anything else?


If somebody has other suggestions, seeing that the snap hasn't improved or disappeared with these oil changes, please feel free to chime in. Starting to get a little worried now...

 

OK.

Rubber compound gasket, and down here are sold as a "trans filter service kit", including gasket, filter, and any odd o/rings etc needed. depending on the trans being serviced.

I would be checking the adjustment of the shift cable. Thats the one from the throttle capstan to the trans. I did mine by guess, and eventually got it where it was sweet as. Sounds like yours it TOO tight, so back OFF the adjuster 3 flats of the locknut, and try that, and keep going until satisfied.

There would be a spec, and procedure, but I dont have it.

 

Will try our local dealership for the gasket and other stuff that might be necessary.

I'd appreciate it if someone could find that procedure! I'll try slacking the cable a bit at a time in the meanwhile...

 

 

I just managed to take off the pan. Inside looks clean, magnets have some muckon them but nothing too bad, filter also doesn't look filled with mud or muck, but I'll first get a new one before cutting this one open to see.
Now that I'm "in there", should I take off the valve block as well and clean the valves/solenoids, or am I better leaving those alone?

 

I would leave it be.

The trans is working, albeit strangely, and that shift control cable, stale fluid etc etc, are at play.

Mine had 8 fluid drop and refills, via the large fill tube nut, approx 30kms apart, before what came out was the same colour as what was going in.

I used Multi Vehicle Fully Synthetic Fluid, and the lock up smoothed out after 4 changes, and the cable was eventually where I wanted it after about the same.

Now, the changes are so smooth, it is the tacho drop that gives the clue its actually changed gear.

The 80kph lockup is not felt at all.

 

Do you have any warning lights lit? Have you scanned for any codes? All of the advice re fluid changes is valid, and is a good thing to do, but these boxes are electronically controlled, and it sounds to me as if you have now eliminated the fluid as a potential culprit. There is a sort of "limp home" mode for the gearbox, where first is locked out, and the other gear changes are "hard", ( I think because the ignition timing is no longer being retarded for each change). /this mode is usually accompanied by the orange transmission warning light.

 

The 4HP22 is a non electronic transmission. No codes to be thrown, no electrickey inside as such.

Strong as they come, just LOVE fresh fluid often.

It is the 4ltr that got the 4HP24 electronic trans,, and all the issues that went along with that, but fresh fluid in those has also made a world of difference for me on the 2 I take care of.

 

Thx for the replies.
I know this thread has been going for some time now, but I'll keep you updated with the results! Might not be tomorrow though...
I hope I will get to take her out this summer, but seen the current sitution I'm not sure about that.

 

Could someone please confirm the correct dimension (and material) for the O ring between the filter and the valve body please?

I find on the interwebz different suggestions, e.g. 37.40 x 1.80 and 38.00 x 2.50
I guess a regular NBR shore 70 will do just fine (or do I step up to viton rings)?

The correct dimension is much appreciated!

Edit: I ordered 38 x 2.5, it seems the correct dimension. Also, for transmission oil, viton is recommended due to the long time at high temperature. NBR risks to fall apart.

 

Can anybody confirm that the procedure for adjusting the shift cable, as described in the Haynes manual for the XJ40 (Haynes # 3261 XJ6 1986 - 1994) for the gearbox ZF 4HP22, is also applicable for the same gearbox in an X300 vehicle? I suppose it is?

 

I can't think of any reason that the adjustment procedure would be different between the XJ40 and X300. The gear shift levers and cables are the exact same parts on both models.

Cheers,

Don

 

Thx!

 

While tightening, it seemed that a slightly thinner O ring would perhaps be better suited (2.25 instead of 2.5), but I doubt this makes much difference in practice.

Here's what I used:

 

Tip of the week:

I use the base of an old office chair to put my oil drain pan on, to use as a tool cart or for a flash light,
also very handy to support an oil pan when you're alone to assemble this kinds of stuff.
The lift system of the chair with a wooden stick, and presto: you now have both hands free to loose your screws.