As far as rebuild kits goes, can anybody make some suggestions? i was considering going with rock autos deluxe rebuild kit

 

Hi,

When I considered this, I looked at these suppliers. I would consider this one of the the most difficult home DIY jobs, and not for the faint hearted. https://www.oregonperformancetransmi...-5HP24-RB.html

https://www.transmissionpartsusa.com...its_s/3969.htm

Madhatter has just done this, so you might want to PM him and get some recent guidance.

I just started getting some jerky down shifts when hot, and in the end I pulled the tranny pan and didn’t see much wrong. No bad metal on the magnets. My ATF fluid and filter renewal and replacement, plus the Transgo PR valve upgrade, sorted out my problem. FWIW Worth a go before you start stripping and rebuilding.

 

Just installed a rebuilt transmission on my 99 XK8 because the A drum failed Went for a complete rebuild because original had 90K miles on it and I didn't want to pay for labor a second time if some other part failed. Rebuilt unit contained several upgrades from original. $3900 out the door including labor in SF area. .

 

I had a shop in LA offering rebuilt units super cheap. I actually went up and grabbed one, gave them my bad one as a core, and brought it home. They offered a warranty for their rebuild, but something wasn't sitting right with me. I opened up the pan on the "rebuilt" transmission and it was used and already a grenade. The shop in LA was aware of it and was just hoping I wouldn't complain or ask for my money or transmission back. I did go back and chew them out and get my transmission back and then reported them to the proper authorities so they can deal with the fraud claim.


Once I got my transmission back I went to a transmission shop that is close by and they did amazing work for me. They rebuilt my transmission for me, including installing the transgo valve kit, and had upgraded aftermarket parts to attempt to prevent the common failures that happen in these transmissions. They rebuilt the transmission for me for $1,900. I believe they wanted $700 for labor if I was just to hand them the car and they pull the transmission, rebuild it, and reinstall. I was able to remove and reinstall the transmission on my own in my garage with simple tools and it works perfectly. Money wise, it would probably be wiser to just pay the $700 and be on your way. I would have easily made more than that at work in the 20 or so hours it took me to remove and reinstall on my own. Ultimately I needed to get in there and replace all of the cooling system components as well and that was easier done with the transmission out.

 

Having owned a transmission shop for some years awhile back ago I have a few suggestions. The transmission should really be torn down first to determine which kit to buy and if any additional hard parts (drums, shafts, bearings, etc..) are needed.

A standard rebuild kit usually contains all new external/internal seal, valve body gaskets etc. Basically everything to take it apart and put it back together.

Next step up includes the above and the friction clutch plates

Master kit contains all the above plus the steel clutch plates

I would suggest buying true ZF parts. There seems to be a lot of distributors that offer original parts.
Check and research all updates for your transmission and buy any parts that apply
I have found that the tech/sales people are a godsend when ordering parts for most popular transmissions. Because they know what parts they sell everyday to rebuilders everywhere. With certain units the particular failures repeat themselves time and time again. Trust me they know their stuff.
Would also say go with a supplier that moves a lot of product. Kits and product do get updates fairly often and you want to make sure the parts you're buying are the latest available.

As some have already stated a transmission is not for the faint hearted. If you have no experience rebuilding transmissions a ZF unit is not the place to start. I owned a shop for over five years and watched many rebuilers work first hand and I wouldn't even consider doing one myself. A transmission has to be 100% just to work. It has to be 1000% correct for it to last any length of time. There's a reason rebuilders make the money they do. There isn't that many good ones and the good ones make serious bank.

 

OH also, beside replacing any and all heater core hoses, octopus hose, cat gaskets, throttle body gasket, whatever you plan on replacing while you are removing the transmission....

Plan to inspect and possibly replace the rear main seal. Mine was leaking and i hear that a lot of other peoples were leaking as well.
In addition to the rear main seal, take out and reseal the brass casting plug above the rear main seal that also was leaking on my car, among others.

If you need new cats, now would be the time to do that as well, the angle of the flanges makes those moderately annoying to get those in and out of the car.

 

+1 to Mad Hatter,

Here's few pics from the Jag Manual showing what MH is referring to. These parts are cheap and, with the transmission off, easily installed.

 

Just FYI I have a 1999 automatic out of my XK8 coupe that according to paperwork and receipts has 20,000 miles on a $7000 rebuild. I replaced the engine and trans....so I have no need for the lot. I'll take $1500 for everything. Engine and trans are a pull out with everything in tact. The engine doesn't run, my mechanic thinks it has a blown head gasket. It's had the timing chain gear replaced. Lots of extra parts for the purist. Engine and trans are in Ocala, Florida. Buyer pays any shipping costs or pick it up! The car Vin # is SAJGX574XVC004824 I have no use for eng/trans as I put a LS combo in my car. Cheers!!

 

Sorry I miskeyed the year of my tranny it's a 1997.....

 

My 1999 XK8 seemed to slip once it got warm and would chirp the tires. Took it to two different transmission shops and diagnosed to needing a rebuild. I went with the second shop (was very experienced with ZF trans.) with a quote of $2,800 - $3,000. The drum was bad so assumed that was the problem, but trans was completely rebuilt. After rebuild the problem still existed so shop pulled transmission again and reinspected and found no issues.
Discovered I found the most honest transmission shop owner ever. He told me to come pick up the car and the charge was $0, he wouldn’t even allow me to pay for the fluid or parts. Said in 30 years of repairing transmissions he had never failed to make everything right….recommended a frame shop to check for rear end slip or shaft issues, wanted me to just let him know what the final fix was. No issues found by the frame shop.
Turns out my real issue was and still is idle speed, once warmed up idle speed drops to 550 - 600 RPMs. If I ease into the throttle off the line all is good or if I hold one foot on the brake and up the idle to 750 RPMs all is good. I hate to do it, but need to adjust the TPS to move warm condition up to 750 RPM.

 

Hats off to that transmission shop. For sure a very rare element this day and age....

 

You might want to adjust the accelerator cable to get the idle up to the required RPM's.
This is a easy fix for a loose cable.
When you start playing around with the TPS some strange things happen, very sensitive.

 

I have taken up the slack in the cable and if I go a little higher on the cable the warm idle is too high.

 

My 1999 does the same thing. When I start it cold the trans pressures seem really high and it will slam into drive or reverse. I am guessing it adapted the pressures up. Engagement off the line is fine. As the trans warms, it seems as if the pressure drops and you need to slowly apply the accelerator so the gear engages. I installed the transgo kit with the modified valve but it did not seem to do anything. Any ideas on what failed? I think raising the RPM is just compensating for a pressure loss.

TJ

 

I had a total transmission and throttle body rebuild with no change in transmission engagement. My warm idle is supposed to be 750 RPM, but is 550 - 600 RPM. I can ease into the throttle off the line and it engages properly. I can bring up the idle to 750 RPM with my foot on the brake and can accelerate as fast as I want without issues.
I’m convinced that if I can get my warm idle up to 750 RPM all will be good.

 

Galearmstrong.....have you found a solution yet?

TJ

 

TJ,
No, I haven’t found a solution for my low warm idle issue….still around 550 - 600 RPM’s.
With all of the problem’s I’ve heard about adjusting the TPS in this forum I haven’t attempted that yet.
Any idea’s would be appreciated.

 

I'll give the idle adjustment a try this weekend and see what happens. I assume your idle is 500-600 in drive when warm, not neutral? Which trans fluid are you using? Do you have the transgo kit?

TJ

 

Yes…550 - 600 RPM in drive when warm.
Trans. was rebuilt with Jag. recommended fluid and RPM was the same before and after rebuild.
No transgo kit….or at least I don’t think so.

 

Just as a data point, I ran this re-adaption procedure. Idle is the same @ 600 in drive and it still slips and bangs on warm takeoff.

https://www.autoecu.com/jaguar-xk8-b...disconnection/

TJ