Long story short: A drum failure on my 1997 XK8, parked in garage for couple years while finishing up house projects. Bought a donor XJ8 for parts. Assume (I know) the tranny works as the engine was the problem. Have the tranny on my tranny stand in garage. I know a fair amount about cars but have never been inside a tranny.

What should i do:

1. Replace valve body (Sunbelt?) and install?

2. Same as 1 but replace a few more pieces?

3. Full on rebuild by a reputable shop?

Obviously there is no "right" answer, I just want some input from the peanut gallery.

Brian

 

My 2 cents (worth every penny):

When mine went out, I did the full monty with a transmission shop specializing in euro transmissions. Lots of ZF experience. I did not feel I was up to doing it myself even though rebuild kits are available. Take a look at the ZF parts explosion chart and you will see why.

They did a full rebuild with A-drum and torque converter being the main items, plus all gaskets, clean passages, etc., etc.

Total cost $3800. Shifts perfectly now and hopefully is good for another 100k+ miles. Warranty included.

 

+1 on Mike's advice of rebuild from reputable shop. See my recent post on repair costs
https://www.jaguarforums.com/forum/x...-p1747-173644/


Post #8 of this thread has link to Eriksson Industries - they quoted me $2295 + $700 core and shipping to/from. Might be the way to go if you don't have a local shop and have the means to install yourself

 

Yeah, I am leaning to a full rebuild as I only want to do this once and get it right. The car is in good shape, but a 3-4k rebuild on a 97 XK8 with 145k miles if a tough pill to swallow.

Thanks for the input.

B

 

If it was me and I was able to get a trans in and out of the car without too much trouble, I would use the donor trans as-is, do a proper service on it (filter, pan, fluid), and keep hoping it would run. This is the low dollar plan, just like you seem to be doing this far. As you know, any issue with the valve body can be dealt with without removing the trans from the car, so not too big of a deal. Once proven to run, I would look into that upgraded valve in the body for longevity and preservation of the A drum.

On the other hand, if you wanted to do a better restoration, and keep the car "for ever", then clearly now if the time to do it. I would start with locating some kind of rebuild manual, check for any funky tool, and try and do a rebuild myself. There are rebuild kits out there that have pretty much everything. When you think about it, you even have a spare trans to play with, and learn from. I would take lots of pictures, buy a box of zip-lock bags to keep thing organized, and fix it. Just my thoughts.

 

It is not difficult to replace the transmission just a little time, muscle and a transmission lift. This link provides information that might help.

Link JagRepair.com - Jaguar Repair Information Resource

 

Check the link below, particularly the posts by motorcaman and BobRoy:

https://www.jaguarforums.com/forum/x...d-drum-174373/

 

I'd use it as-is but replace the problematic valve before installing (so not exactly as-is!).

 

+1 bladerunner

While the pan is off look for metal bits or excessive metal filings on the magnet. If you find these it will point to possibly failing A drum.

If your planning to rebuild your transmission why don't you do the one in your car instead of buying one and then have it rebuilt?

 

If you have the transmission out, doing a rebuild yourself is not a horrendous task. The exploded view diagrams look intimidating, but you'll find that it is really not as scary as it looks once you dig into it. It is basically a stack of components. Few specialty tools are required and most of those can be fabricated in-house with a bit of ingenuity. Pay careful attention as you disassemble and document, especially the location of each bearing.

Purchase a good quality kit. You can steer short of the 'master' kits which generally include all the bushes. You can't do those on your own without specialty tools, and unless you tranny suffered catastrophic failure or is very high miles, they won't need replaced anyway. and above all, buy the overhaul manual! The extra $30 is well worth it.

Employ a shop for anything that you can't do on your own. I farmed out the valve body as I just didn't want to deal with it.

Give it a shot! It is very satisfying to do that job yourself and know you just saved 2 grand!

 

Let me ask about the A drum failure. Is it something that wears down and down until it finally snaps, or is it in good condition for a long time until there is a pressure spike and then BOOM it fails at one shot?

B

 

You decide:

drum-damage-169154/

 

From what I have been told the “A” drum failure could be caused by a few things. Fluid pressure, bearing worn and I forget the rest. Know that if you have shavings they will also be in the trans and torque converter so cleaning the entire transmission housing is a good thing to do. However, many have just replaced the “A” drum but I do not know how long the repair lasted.

 

I would just swap the whole transmission for the XJ8 trans and be done with it. Then pout your XK8 trans on the workbench, rebuild at your leisure over the next 6 months and either keep it as a spare or sell it as rebuilt.

If you have a drum failure I think you want a new drum at a minimum and you will have to pull it anyhow.

I agree with mhminnich on rebuilding. I have rebuilt a couple transmissions, never a ZF but they are all similar. It is time consuming if you haven't done it before and don't have manufacturer's tools but it isn't hard. Buy the ATSG manual and just go through it step by step. First one I did took me about 100 hours, second one about 30 because I understood what I was doing a lot better. A lot of that time is spent either fabricating tools or trying the same thing over and over because you are using pliers and screwdriver instead of a purpose-build spring-compressor/remover and that works but it just takes a while.

 

I am just about to start this project as well. I am hoping to just replace the A drum, looks pretty simple once I get the transmission out. I just ordered a transmission jack adapter and am looking at A-Drums. Not to expensive, one is $145 built in USA and $100 for China. Not sure if there is any difference.

My reverse and most shifting is good, just the first bump from a standstill so I hope it is just the a-drum. I only have 85k on the car so all the clutch rings may still be good.

A few questions for those in the know:

1. Any advice or forwarnings when dropping the transmission (hard bolts, plugs or other thoughts)
2. Has anyone replaced the preassure valve, if so was it complicated. I think you need to go deeper into the transmission to get to the valve vs. just the drum.

 

I would drop the pan first to see how good or bad it might be.

 

+1 Gus. Scott- go back to my post #7 and open the link. Pay attention to posts by motorcarman and BobRoy as to what to buy.

The main pressure valve is easy to change when the filter is removed, it's part of the forward valve body.

http://jagrepair.com/images/AutoRepa...%20ZF5HP24.pdf

 

I asked Cascade the difference between the two compatible drums they sell this is what they replied.

yes , both are heavy duty and not China copies of the oe drum

the one shown in this listing uses a special style snap ring to hold the pressure plate all the way around
we have you tube videos for this and the snap ring install

the other item # 131950113773 is by far the best drum on the market
it's much thicker that any others , and the design of how they made the snap ring groove is more unique
they didn't cut all the way through and around the drum -
if you drag and dropt he images to your computer and do the same with any others you find for sale
when all side by side compare the snap ring points and i think you will see the differences more clearly

we stock everything possible for these , and we also have full rebuild bundles with both of our drums included
those bundles are the best deal going right now and save you about $250 vs buying items separately

 

As I research I will get the drum, the grease, new fluid, and the valve. (my filter and fluid are pretty new but looks like you need to empty the fluid to get to the valve) I will also try to figure out what gaskets/rings I need if I do not go any further into the transmission than the drum and pressure valve.

Parts are listed here:
https://www.jaguarforums.com/forum/x...9/#post1597816

 

Having owned a transmission shop for several years in the past this is my advice. Just install the donor tranny as is and see what happens. It's also your cheapest option. I would not even service the donor tranny till after you install it and make sure it works like it should.

Rebuilding automatic transmissions is almost a black art due to their complexity and that's why trans re builders are among the highest paid auto techs in the industry. An automatic transmission to work properly needs to be rebuilt 1000% correctly there really is no room for error. If you have never rebuilt transmissions before a ZF would not be the one I would suggest you attempt to learn on. Hope this helps and good luck which ever way you decide to go.

Cheers!