Well after just two weeks of being on the road again after replacing the engine, my 99 VDP suffered a transmission hiccup yesterday. I believe from all the other transmission threads on this car that it is the dreaded A drum failure. It showed the classic symptom of getting stuck in first then banging into the higher gears. I had it towed home and am going to pull the pan down today and check it for debris. I was going to go ahead and fix this while I had the engine out but I decided to gamble and lost. Now I will have to pull the transmission and go ahead and fix it right. I am planning on replacing the rear pinion seal as well while I have the drive shaft loose. I am still torn on whether I want to try to rebuild the transmission myself or just replace it with a remaned unit. I have plenty of mechanical skills, however I have not tackled a transmission rebuild before so I am a little hesitant. I have read and looked at plenty of great threads on the rebuild process and it seems like it is something that I could handle, and it would save me quit a bit over getting a remaned unit. I would also feel better knowing that I did it the right way and not having to question whether they replaced all the right parts etc.. Well anyone that would like to chime in on their experience with transmission issues would be great to hear from.

 

Well I pulled down the trans pan yesterday and it has the normal small amount of metal around the magnets. The oil was pretty dark too. So hopefully I caught it before the A drum completely failed. Pulled the exhaust down and removed the drive shaft yesterday. Todays project will be to get the trans out and maybe take some of it apart.

 

I have replaced 4 forward ('A') drums and the pans had no abnormal amounts of debris.
The frictions/steels are almost always reusable but the 'O'rings get damaged by the 'piston' assy moving too far and getting 'cocked' as the retaining ring groove splits on one side.

I just buy the updated 'A'drum from transpartstech and a gasket seal kit from CTSC

Overhaul Kit 5HP24

You can get a filter kit from rockauto for cheap.

As stated, the VW fluid is cheaper than Jaguar fluid. You can also use Pentosin ATF1 from O'Reilly for $14.99 a liter.

You can change the filter and reinstall the pan, then remove the gearbox.

I tilt the gearbox vertical with the bellhousing UP. Remove the torque converter and dark bolts (leave the gold colored ones alone). Pull the bellhousing/front pump assy and remove the drum cluster STRAIGHT UP without disturbing the remaining clutch locations. Replace the damaged drum and reassemble with new 'O'ring and a new pump-to-case gasket.

You can suck/siphon the fluid from the torque converter when it is sitting on the workbench before it is reinstalled in the trans. Top up the gearbox with fluid and you're done.

I have never needed to actually rebuild the entire gearbox, just replace the damaged parts but that is your call.

The fastest I have done it was about 7 hours but it will take longer if you have not done it before and if the exhaust cataverter bolts snap like they usually do.

bob gauff

 

Thanks Bob, I have managed to get the trans out and got it all disassembled down to the a-drum. Does not look like there is much damaged yet. Noticed the o-rings have seem to have lost most of their elasticity. I am guessing that is what has caused my initial slipping the other day. I will replace the a-drum and reassemble with new o-rings and hope for the best. Is there a good way to compress the piston back into the a-drum so I can get the snap ring back on? It took a bit to get the snap ring off and now I am thinking how am I going to get those spring cups compressed enough to get that snap ring back on. I have access to a press and I was thinking of some way of using that but do not want to damage anything.

 

Don't forget the thin 'O'ring on the outside of the drum at the base of the input shaft to the torque converter.

I used a pitman arm puller (U shaped steering tool) with the arms down and a shop press to press the internal piston for removal and installation of the snap ring. Any U shaped or C shaped piece of metal can be used.

If the forward drum is not the problem then it might be another fault with the gearbox.

good luck

bob gauff

 

Very good idea Bob, I def have a pitman arm puller. That should def do the trick with my press. Thanks for the reminder, I am going to replace any o-rings that I can see while I have it apart, however I did definitely notice that that thin o-ring looks like it is ready to go anytime. I am hoping that was the cause of the slipping. This car did alot of sitting, only 54K original miles on the drivetrain. Alot of my rubber is starting to show the effects of sitting. I noticed in a thread from the bimmer forum that the guy was saying there was an issue with the reverse piston. Do you know or anyone know about this being a common issue. I would like to address any issues but getting to the reverse piston means gutting the entire trans, since it is all the way in the back. Adding a couple pics of the trans so far.

 

I am certainly above my experience level commenting on transmission repair but wasn't there some discussion on valve body issues causing the A drum failure?

 

I have not heard much about any major valve body issues, however I would like to know now while I have the trans out and am working on it.

 

Hey Jeff, some great pics you posted there, but why in thumbnail image?

It'd be so much better for the reader if you can post them into the thread.......I'll try and get round to editing your post to make this happen.

If you need any help in being aboe to dothis please just check out the post pics thread in the help n suggestion centre, or one of the mods or I would be happy to help if needed.

 

Jeff -
What is your work surface, the thing that looks like a big grating?

 

Hi
Here are weblinks to the Valve Body Threads and Posts (comments first, then weblink):

start with reading post# 1. Post# 2 has links to ZF5HP24 Transmission Repair Manual and a TB on replacing the valve body. Posts 3, 4, 5 have additional information.
https://www.jaguarforums.com/forum/xj-x308-xj8-xjr-27/there-way-inspect-tranny-valve-body-assembly-54866/

read posts # 2, # 3 and # 4
https://www.jaguarforums.com/forum/xj-x308-xj8-xjr-27/transmission-front-drum-49485/

PDF with Removal and Install information pertaining the XJ8 transmission
https://www.jaguarforums.com/forum/xj-x308-xj8-xjr-27/zf5hp24-r-i-extracts-jtis21-cd-faq-54942/

Jim Lombardi

 

Jim, you are a treasure!

 

Jim, can we get you appointed official Thread Librarian and Researcher?

 

Thanks again Jim, will def take a look and see if there is damage in the pressure regulator bore. I will see about ordering the pressure regulator as well. Got in my new a-drum from a great vendor on e-bay cascadetransmissionparts. It was 232.88 and included priority shipping and it was here in a couple of days. Boomer, my transmission stand is just a plastic shelving unit, thought it was good so the trans fluid drains below to my catch pan. JimC64, I had tried to add photos to my post and eventually gave up. One time will have to take some more time with it and I am sure I will get it.

 

Well guys I tore into the valve body this morning to take a look at the pressure regulator valve. I pulled everything apart and to me it does not look like there is much wear in the bore, however it is very difficult to see all the way down in the bore. I was wondering if any of the techs out there could give me a better idea of what I am looking for as far as wear in the bore. I will add the pictures of taking it apart and the best shots I could get down in the bore.

 

Hi
Try calling Nat - owner of Eriksson Industries - the ZF authorized Transmission Repair Shop - about the bore sizes and the acceptable tolerances (to see if you need to replace any of the valve body blocks). And Yes, they sell & ship transmission parts. They are located in Old Saybrook, CT
1-800-388-4418 here is the website address: Eriksson Industries

Here are photos of the 2 valve body parts that ZF Authorized Rebuilder Shop replaced.

These 2 photos are two different view of part# 1058 427 022 (Valve Body)




Here is the photo of part# 1058 427 068 -(upper valve body block)



Also I found the following comments about these 2 parts:

Taken from the audiforums thread 8/1/2010

The valve body (part# 1058 427 022) on the ZF 5 -speed series is notorious for wearing out inside the piston bores. Once the bore has worn sufficiently, too much pressure is allowed to be applied to the clutch/brake pistons. The " A " clutch, must be the weakest link.

Take from landrover net website thread 6/16/2011

Failed upper valve block as a 1058 427 068.

Jim Lombardi

 

Thanks again Jim, will def find out about the bore specs. I found this youtube video showing them testing the deviation of the bore.

FixEuro.com - ZF 5HP24 Regulator Deflection Test - YouTube

 

Hi,seems that a new updated valve is 20 dollars; it should be a must,like the upgraded timing tensioners.

How much time takes to dismantle the valve body?

Main Pressure Valve 5HP24 - 5HP30

 

Well I ordered the new valve, now I have to see if it is the bore that is worn or the valve. Still have not had a chance to check out what the specs are for the bore etc. I did the same deviation test as shown on the video and came up with about the same results. Valve body is pretty easy to dismantle. I think they are T20 torx, and really you can do this without removing the trans when you do your next trans fluid change. You would only have to drop this part of the valve body to replace the necessary components. Well worth it. I have not found out what the price is on the housing for this valve if it needs to be replaced.

 

I'm speechless....

This thread is invaluable and should be made into a sticky.