Hi all--I have a 1997 Jaguar XK8 with a broken transmission (car won't shift, metal in the fluid). Shop wants to replace the transmission, but can't find an exact replacement from a '97 XK8. I can find dozens of transmissions for '98-2001 XK8s, both rebuilt and used. However, I cannot find a replacement #1058000015.

I have been getting a LOT of conflicting information here-- A large number of people are saying that it's fine, all 5HP24 transmissions are interchangeable (although they never explicitly mention 5HP24 transmissions with different serial numbers). An equal number of people say that you ABSOLUTELY MUST replace the transmission with an exact, identical part number replacement, and if you don't then the ECU will throw a fit and the transmission won't work properly. #1058000015 transmissions are getting hard to find these days, and really I would prefer to get a replacement transmission with the upgraded A drum if at all possible.

My question is: which is it? Do I have to find a replacement transmission with the serial #1058000015, or can I swap it with a 5HP24 transmission #1058000013 or #1058000026?

 

The internal harness does have different part numbers for the AJ26 and AJ27 but I have installed a later gearbox (xxxxx026 into the earlier car with a xxxxxx015) and it worked OK, No Issues.

The easiest way to get the upgraded front drum is to install it before you install the gearbox.
I always pull the bellhousing and replace the drum on ANY 5HP24 if I have to remove it for any reason. Easy enough unless the customer tells me NOT TO.

I used to buy the solid drum rebuilt from original cores. I still have one left and I think the seller was transpartstech in Michigan or Indiana??

bob

 

Call ZF Tech Support in Chicago tomorrow and see what they have to say about this. The phone number is (800) 451-2595. Ask for Steve Jaffe or Joe Laubinger….

 

I have a rebuilt 1997 XK8 transmission and engine removed from my coupe in the for sale section of this site. As far as I know it is the original transmission with a $7200 rebuild 20k miles before the engine blew. If interested my mechanic can check part numbers after he gets it out this week. You will have to tell him where to look as he is not a jaguar mechanic....

 

Hi silverandbrass

i have a quedtion for you if you don’t mind.
I have a 99 XK8 and I’m trying to determine what model my gear box is for a replacement valve body
nothing is easy with this car, after lifting the car I see the green tag is coverd by the gear shifter which is behind the muffler, so I can’t see which box I have.
does your year have same issue, if so what did you do to get access?
im a little concerned about taking gear shifter off since the muffler is in the way. Have any problem getting your number?
let me know if you can, thanks!

 

Well I figured it out without removing anything
i stuffed my phone up there why videoing and got look at it
its a 26, don’t know if that is good news or bad
thanks for listening

take care

 

SilverandBrass,

Wise words above esp. from Bob, and BigAlBre has also been good to offer you his.

My two cents - if you've any doubts, it may be worth sending your ZF unit for repair/overhaul as you'll know it fits. Jon89 has given you contact details of ZF support so they'll direct you to a good shop. I appreciate this is the long winded method though and your car will be "down" for a while.

If there are any doubts, the worst thing is to get new re-conditioned unit only to find it doesn't work in the Jag.

 

I'll be honest, I have no idea exactly where the information plate is located on the transmission--I just asked the guys at the repair shop what the number was and they told me! I'm glad to see that you eventually were able to find a workaround.

 

I have gotten thoroughly confused by what I've been told about the '97 XK8 tranny. Mine is VIN SAJGX2749CV010936 with c.100K. It's been well cared for, including the big set about 65K or so. My main mechanic says the tranny failure is a known, design problem (it works fine in lower gears and reverse but not in the upper range). But does this effect only a few, some, most, or (eventually) all? Is it worth repairing or replacing mine if I can expect that the replacement will likely crap out in the same way. (I'm approaching 77 but would not like to throw money away!) He also said that only the "A pack" is the problem (exact meaning of this term unknown to me but perhaps what others mean by the "front" module) so perhaps replacing only part of it would work. I have the full set of shop manuals so should be able to follow your technical comments reasonably well. This forum has ALWAYS given me great information so I hope you will come through again. Many thanks!

 

Jfhuntsman,

The short answer to your question is “Yes” - there are known problems with the ZF5HP24 gearbox. Probably that’s why Jag went to the better merc 722.6 then the ZF6 gearbox, all during the X100’s model Range.

This forum has seen plenty of these problems and there are known mitigation/prevention solutions.

It certainly didn’t help that the manual says “Sealed for life” so the “layman” owner type wouldn’t have serviced the filter and changed the ATF gearbox fluid.

Known problems are
1. Weak A Drum- with ZF and after market upgraded part available
2. Valve body Pressure spikes due to Bore wear - I installed an upgraded Transgo PR valve
3. Valve Body F channel cracking

It’s fair to say that these units are almost 20 years old and age gets to everything. Solenoids can fail too. Electrical connections may wear and corrode etc.

Also the x100 is a grand tourer so a six speed gearbox is way more fuel efficient on long drives which is why the ZF6 is a better choice.

A bad gearbox service too has been seen a few times too even by professional shops. Simple example is too much ATF fluid added causes foaming and gear slips. Job has to be done twice as the Torque Converter holds fluid, so drain and fill 2x to ensure you’ve gotten rid of most of the old ATF.

 

Thanks VERY much. It looks as though trying to fix the original could turn into a real mess with labor alone, so unless the cost of a full replacement is prohibitive (as it may be, being a Jaguar and all...) A couple of follow ups: is the Z6 a bolt-in replacement or are modifications necessary? What is the full part/model number for this Z6? (A quick web search implies that there are Z6s for Honda--presumably not the same at all--and for XKR '07-09 C2P2156, which just might work.) Are there any problems I might look out for in searching for a replacement? Any source out there you'd recommend? (Like most, I have had mixed results from eBay but generally pretty good since I am very careful about what I buy--with a little help from my friends, always gratefully acknowledged!)

 

If you mean the ZF6HP26 then it cannot be used to replace the merc one or the ZF5HP24.

 

+1 to what JagV8 said.

jfhuntsman - SilverandBrass' original thread title is ""97 XK8 Transmission Replacement--are all 5HP24 transmissions interchangeable or not??", so please do not confuse my thoughts on the problems with ZF5HP24 gearbox and think you can just replace it with later Merc 722.6 and the ZF6HP26 transmission units. That's not going to happen easily.

Anything is physically possible but it's not just the engine/transmission connection that needs to be reworked, but also the multiple control modules/sensors which communicate with each other. IMHO if you're at this point of consideration, you'll be basically better off buying a later MY2003+ X100 entire car.

 

jfhuntsman- you say it works fine in the lower gears but not in the upper range. That is not an indication of the typical A drum failure, in which the transmission has a delayed start in first and the starts with a jump. Check the fluid level before taking more drastic action.

 

My apologies for misinterpreting your previous answer. I had SEEN discussions that indicted that the 1997-98 XK8 models used a certain version of of the transmission but that the subsequent years used one that was different in some way. However, other sources contended that the whole XK8 run used used functionally interchangeable versions. Hence my thread title which was are all 5HP24 transmissions interchangeable or not? If that title plus my commentary was not clear what my issue was, I apologize.

But you replied "The short answer to your question is “Yes” - there are known problems with the ZF5HP24 gearbox. Probably that’s why Jag went to the better merc 722.6 then the ZF6 gearbox, all during the X100’s model Range." This COULD be interpreted as meaning that the later 722.6 and ZF6 units just MIGHT work in the earlier XK8..Your second reply seems to chide me for asking for this clarification, so I am assuming that my inference about the POSSIBILITY of a backward compatibility of the later units was an incorrect one. I could wish that your answer were different, because now it looks as though I'm probably unwise (at least financially) to try to fix mine, but I am nonetheless grateful for the truth of the matter.

 

Sorry! My original question seems to have gotten lost. Very briefly: I have a '97 XK8 (ca. 100K) with a bad tranny. I understand that this is a design flaw so that just putting in another of the same type would not be wise because the replacement would be likely to fail in the same way. One respondant mentioned a couple of later models that were more reliable, so I asked if the later one would readily work in the XK8. The answer seems to be "no". Although it now looks as though I'm going to have to junk my XK8, I am in no way unhappy with the responses of the posters, and I apologize if I seemed obtuse in any way. .

 

Sorry--I must have misremembered what my mechanic told me about the precise location of the failure. I appreciate the correction. (He DID replace the fluid, of course. He is more a specialist with the high-end German cars than with Jaguars, but in many years very few things stump him, including the Indy cars he fixes on the fly in the middle of the races. He is not responsible for MY mistakes in reporting the precise details.)

 

jfhuntsman - you can have the transmission rebuilt - just use the uprated A-drum and install the trans-go valve body to help increase the life of the rebuild. I have had mine rebuilt and am currently pushing 180000 miles

 

jfhuntsman

Apologies if the tone of my response offended you.

It does seem that you're in a difficult spot now, esp. concerning the value of our cars now, versus the cost of repair. Unfortunately that's just the way with old cars, where only "Sentimental owners" appreciate their cars beyond the rational, enough to pay for a repair which costs more than the value of the car. Also during the long repair, the car will be down and off the road.

The good news is that the ZF5HP24 gearbox is very common across a number of different car brands so there are rebuild kits readily available that remedy the known faults. Virtually every specialist transmission shop will have done a few ZF5HP24 re-builds.

It doesn't hurt to get a quotation but include the cost of removal of the gear box out of the car and delivery to your chosen specialist transmission shop. That'll give you a better position to make an informed decision.

Again - apologies - but sometimes the truth hurts.

 

jfhuntsman - Eriksson Industries has been recommended a few times on the forum. I would have used them to rebuild or replace mine but I was fortunate enough to have a local shop familiar with the ZF's that did the rebuild along with a 2 yr 24000 mile warranty.

Check them out Jaguar