ok, back story is the car sat for almost 2 years as the elderly original owner was too sick to drive. i was given the car in january and almost straight away the usual gearbox problems started, the occasional delay into D or R from N and the typical thump and also the dreaded no gear followed by a huge thump after slowing down to a stop too fast.

i dont drive the car much, probably 1000 miles since getting it and i'm surprisingly gentle during the potential problem moments.

i spent ages researching the web and read all about the drum failures and valve bodies in the 5HP24 gearbox family. the general consensus was that wear in the pressure regulator valve allowed excess fluid pressure which makes the A drum pop its seal.
i decided to do a fluid and filter change using a Meyle kit from ebay, £130 with new bolts, magnets etc. the fluid came out black and really stank, of course it had never been changed and probably never topped up in its life, thanks stratstone for your comprehensive full service history..

with the pan off i checked the valve body for signs of the potential cracks that i read about, there didn't seem to be any so i fitted the new filter etc and gave the car bit of a drive (i went on holiday in it)

as expected the original problems were still there but slightly worse.

during my original research on these problems i came across a company in the US called Transgo that makes specialist transmission parts including a pressure regulator kit for the 5HP24, they call it 5HP-24-PR, it cost me around £80 with shipping and VAT.
Transgo state it won't fix a broken drum but can help avoid it along with 'runaway pressure, harsh shifts and kick-down bang.
as my drum isn't broken and i have no fault codes etc i thought it wouldn't hurt to try it.

the kit comprises a new valve, spring and special seals and can be fitted with the gearbox on the car.
it took me probably 4 hours start to finish to fit, i reused my fluid as it has done only 400 miles and looks very fresh but i did decide on a filter.

i took it for a drive and it does seem to have worked, all the shifts are very smooth. of course time will tell if its a permanent fix.

 

How many miles on her: As a guess I would have said over 75,000miles.
Full Garage service, will usually not include transmission and filter change.
Since not on the Jaguar recommendations for service. Its sealed for life Sir.
And more money for them in changing out the transmission.
Glad you managed to sort it.

 

Hi weatherforcast,

Thank you for this informative post!

I took the liberty of editing your large block of text to add some line breaks to make it less uninviting to read. When you get the chance, it would be great if you could add the appropriate capitalization to make it that much easier for others to read.

Thanks again,

Cheers,

Don

 

That's interesting...here's the link
TransGo ZF 5HP-24: 5HP-24-PR

If this cures the problem then I'd suggest all XJ8/XK8 owners have this installed before the inevitable - fingers crossed!

 

I have replaced the main pressure valve in mine with the ZF updated valve. The use of seals on the TransGo valve is, I assume, to prevent leakage in a worn valve body.
It would be interesting to see data demonstrating the advantage of the seals. I may try this replacement as it is unlikely to have a negative effect.

 

i forgot to say that i also disconnected the transmission ecu to erase any saved data as i read that the ecu detects the leaking pressure valve and can pump up the pressure as it believes its normal wear and tear.

i didn't want to disconnect the battery as i was loathe to lose my impressive 24 mpg on the trip computer

 

You can get better than that!

 

Is the valve included in this kit the OEM ZF upgraded valve?

 

I am placing orders now to perform this service on my 2001 XJ8. I have ordered the fluid and the Transgo kit, but the filter kits range from $17 to $76 for what appears to be the same thing, except different color gaskets. The CTSC kit has new drain and fill plugs, but the kit is $42 more expensive than the filter kit from the same company I am getting the Transgo shift kit.

Is a ZF brand filter worth that much more? Are the cheaper kits NOT ZF brand filters?

I have and will continue to search, but if anyone could clear this up for me sooner I would appreciate it. I want to get all this stuff on the way so I can do the work on my next day off. The transmission shifts pretty smoothly, but it "revs" a little before it engages when idling in a parking lot, and on hard acceleration it "revs" a little sometimes between shifts. No one would notice these things but me probably, but since the unit is just over 98,000 miles with no documented service history, I am really anxious to get started.

Thanks.

 

There may not be anyone still following this thread since no one has responded lately, however, I have received the ZF Lifeguard 5 fluid and the filter kit already and the Transgo kit is scheduled to be delivered tomorrow. I decided to pay the extra money to be safe and bought the ZF (Filtran) filter kit from CTSC.

I cannot find a specific tutorial on replacing the pressure valve but I expect it will come with very good directions.

Does anyone have any last minute tips/advice regarding this service?

Thank you.

 

The instructions appear to be pretty clear. If you don't have an extra pair of hands when removing the retaining plate, a couple of bar clamps will suffice.

 

Everything arrived today. I have one newbie question...

What is "cold assembly gel" and where would I purchase it?

Thanks

 

harvest 14, the instructions seem so simple that they can't be right but they really are.
no the valve is designed by TransGo
i have no idea about the assembly gel, i found the replacement valve slid in easily, but i did put it in the freezer for 48 hours before fitting it so i assume the metal contracted enough, my valve body still had trans fluid on it which helped lubricate.
regarding the retaining plate, i loosened the bolts a bit at a time and could hold the plate when the last bolt undid, i replaced it in a similar fashion. the springs are not so strong as to be impossible to compress.
good luck with the repair

 

Thanks Weatherforcast. I am looking forward to doing this service. I will prepare the valve a day or so ahead of time like you recommend.

I called Transgo and they said "cold assembly gel" is simply Transgel. In fact, he said if I didn't have any that Vaseline will work fine.

Thanks for starting this thread.

 

I have a day off tomorrow (finally) and plan to conduct this transmission service. In preparation I cleaned the new valve with carb/choke cleaner, blew it dry with my air compressor and wiped it down with a paper towel. Then, I put just a little Assemblee Goo into the two grooves and slipped the gaskets in place. I put the sizing O-rings over them to hold them in place, put the valve back in the plastic bag it was shipped in, and put it in the freezer.

The gaskets separate so they can be "opened" and slipped over the valve. This made assembly easy but I worry that they won't stay in place after setting, since they can open up like that. Is that a baseless concern? Should I have used more Assemblee Goo (which dissolves away anyway, right?)?

I just want to be sure since, once installed, this valve will decidedly NOT be easily accessible again.

Thanks,

 

The transmission service finally got done! I went very slow and actually enjoyed myself. The fluid that came out was dirty, but not as bad as I expected. Also, the bolts came loose very easily and the gasket was in great shape; pulled right off in one piece. The filter looked original however so I am conflicted as to whether this transmission has ever been opened since it was built.

The Transgo valve fit into the upper valve body perfectly. It's a bit heavier than the original valve and shaped different; plus it has the gaskets, which the original did not have. I called Transgo three times during the installation to ask questions. They answered on the first ring each time. The person who answered the phone was tech support and each time they patiently answered my questions. Refreshing customer support in this day and age. The installation really was very simple.

The car took ALL 6 liters of ZF Lifeguard 5 fluid I had and didn't overflow until it hit about 51 degrees Celsius. I drained all the empty 1 liter bottles and got about 100cc more, which I put in the transmission using a syringe. Basically it's full, but I didn't have a DROP left over. Made me a little nervous.

Date night with my daughter afterwards, so about 20 miles of test driving. It shifted smooth before this service; in that it paused very briefly and shifted without any problems. It still shifts smooth, except smoother. Sometimes I did not even know it shifted unless I watched the RPM gauge. The most noticeable improvement? When I was idling/coasting around parking lots before, the car would seem to need an unreasonable amount of RPM to engage the gear. It would rev and then "catch". I tried about a dozen times in a parking lot tonight after the service and it never did that. It would immediately move forward when I touched the gas. Very nice.

Yes, I'm long winded. I type fast so basically by the time I've thought about what I want to say it's already on the screen.

Anyway, I am very happy that I conducted this service and also very happy about discovering the Transgo valve.

 

that's great news that you've got it done
i think that the new seals take a little while to bed in and maybe they absorb some fluid before they are a perfect fit as i had a few tricky moments where i thought the trans wasn't right.
like i mentioned in my original post, i don't use the car very much at all so i don't have any further reports on the repair, i'm very interested to hear how you progress with this.

 

So, now that I've driven a couple of hundred miles the car still seems to be smooth. I did not do an electrical reset however, I just started driving it with the new valve and fluid in place hoping it would "learn" any changes it needed to learn.

My main goal for installing the Transgo valve was to prolong the life of my A-drum; if the car shifts better then that's a bonus.

Since it took every drop of fluid I had, there is the mild nagging concern that maybe it's not full enough. I guess it would not shift smoothly if the fluid was low, correct?

 

i've often wondered what the allowable minimum level is of transmissions without a dipstick, as we know there is a maximum and a minimum marked on them.
after all, a sealed for life trans must allow for a small amount of leakage and must last for at least the warranty period especially as they're never checked during servicing.

 

I started adding fluid at about 33 degrees Celsius and by the time it got to 39 C I had added a little over half a liter. At 39 c it started to stream out, so I put the plug back.

According to the ZF video the fill should be done between 30 and 40 C, so I feel like maybe it's at the proper level now.

I am thinking of removing the transmission fuse now to allow the unit to reset. The folks at Transgo recommended doing that, and weatherforcast said he did it also. I never did it because it shifted fine, but I have no standard of reference for what it's supposed to shift like (my first Jaguar).

Question: Which transmission fuse effectively resets the transmission computer? There is more than one.