I have 79.5K on the Jag & 126K on the Audi. Fingers crossed.

 

Trevor - Keep us posted on what you find out... I have the same transmission and "worry" about it in the long run (only have 33k miles so far)... I hope to do the valve change to help reduce pressure on the A-Drum on my trans one of these days.

Thanks!
Chris

 

As I already said it didn't flow out. Level is spot on but again I would typically have enough coming not just barely coming out hence the maybe 1/2 quart low. Quite certain that isn't the issue as if it was that sensitive it wouldn't be fill untill it comes out like a dif. They would use a proper dipstick.

Remember I have two cars, and the XJR is much more of an electrical hog then a lowly base 97 XK. If the battery (well all 3) test fine on a load tester, volt meter and the other car you would still run out and buy another battery.

Actually Jag is quickly making up my mind for me, the ZF has been the worst tranny I've ever had (yes that includes an 83 Century and a Subaru SVX slush box). Going with them exclusively and not offering sticks on top of the lack of the ability to put a tow hitch on 'em because they are recycled beer cans makes me wonder about the future. Was thinking about a 13 xf awd for my wife but if the tranny acts like every ZF I've driven in a X308 or X100 they can keep it.

I'm actually amazed that you made it to 4 trannies before your Ram rusted away. Saw one here in PA that was 2 years old at best (was badged a Ram not a Dodge) that actually had freaking holes in the bed already, not just rust bubbles. Gotta love that!

 

Could be something in the air out your way protecting y'all. Last time I was out there I was so frightened to ride thru after the driving I saw. I have no problems with NYC or even Philly driving but I do draw the line at the woman who passed me going at least 90 in her Geo while breast feeding. Now that takes faith!

 

To preface my reply, I must state that I have the 6hp and lots of miles on her. But when I had the transmission rebuilt to address various codes and slipping high gears, we discovered that the fault ultimately lay in my valve body. Rebuilt VBs with sonnax upgraded valves can be find out there on the internet if you want to try that next.

 

ZF rebuilt the tranny about 20k ago and "upgraded" as was needed. Really well worth it apparently so I WOULD NOT RECOMMEND ZF for rebuilding their own transmissions at this point nor would I ever buy another car that puts transmissions in that fail as often as the 5hp24 has without backing it up and doing the right thing (hence why my next car won't be a Jaguar until they go with a company that stands behind their products).

No codes have come back but it still surges esp in gear going up slight hill lightly on the gas (maybe a slip but tough to tell) Does it more often in sport mode then not. The 3 local shops won't touch ZFs as they have not had luck solving issues that ZF has not addressed in redesigns so Im out of luck there. Maybe time to park it on a train track.

 

I took the liberty to read your thread. The P1798 & 99 both led me to the TCM but first I would have your battery tested professionally. You can take it to any AutoZone, Advanced Auto, Sears or PepBoys and have it tested for free. However, you said that you cleared the codes but you still have a problem shifting. For the shifting I would be looking in several areas first the fluid level then the shifter cable adjustment and then to the TCM.

It is hard to diagnose an issue over the internet and get it right so please understand everyone is trying to help.

FYI When a transmission is sent to you yes it is filled but most often it is about a half qt low when installed. You should always check the fluid level after the install. I will also mention that these cars do not like being a garage queen.

I hope to hear about what you find.

 

Your def of a professional differs greatly from mine as I don't consider most autozone or advance kids with a tool as a professional Besides that was taken care of before I even posted as I put it on a load tester, swapped two that also were put on a load tester. A TCM issue would put codes back out by now for as funky as it is acting but nodda. Shifter cable is fine and as I said if anything it is a 1/2 a quart low but it is right at the fill line so I wouldn't touch it as it is much closer then you actually get with the "proper" zf half butt cheek proceedure.

My cars are anything but garage queens. The XK8 in question just ran the British Relablity Run as my TVR clutch hydraulics gave out on the way to the starting point. That is where it started having issues. It had little issue keeping up with a great sprited driver in an E type as well as a V12 DB7 with a stick piloted by a friend of mind. Our XJ is nothing more than a family truckster complete with a tow hitch that has hauled our camper over much of the east coast (that is until it ripped the camper frame in two).

 

Well I guess you will figure it out!

 

Yeah, I am Gus, following your signature. Realizing that all the "fixes" ZF came up with seem to be nothing more than smoke and mirrors sadly. Aside from my XK that is nothing more than a high maint. pretty woman the othes have been flawless with simple maint. and decent mechanical skills I am simply not at a point I'm wiling to give ZF another dime for a flawed tranny that they simply cannot make last. At least Jaguar realized the error of their ways with the nik. sleeves (even though that was more of a gas issue). At least my TVR has been more reliable.

Still waiting for someone to move beyond the things that have been already ruled out and suggest something beyond the battery. I app. the suggestions but once those things have been tested and meet all specs it is time to say what else is next to test.

 

I think the original Jaguar warranty on your car ran out approximately 17 years ago - if the transmission had failed sometime in that last century, Jaguar would have stood behind their product and fixed it. Its hard to see why, almost 20 years after it left the factory, you can expect them to do anything about it now.

I realise its frustrating, but when you buy a second hand car for 10% of its new price, you can't expect 100% of the original experience.

What warranty did you get from ZF when they rebuilt the gearbox?

 

Now that is the best way to describe any used Jaguar situation. Many suggestions have been made so far and as near as I can tell not one has been tried. And again Trevortasmin we wish you nothing but the best.

 

[QUOTE=1 of 19;1561164]Now that is the best way to describe any used Jaguar situation. Many suggestions have been made so far and as near as I can tell not one has been tried.[QUOTE]


So you have good batteries, Ok you have good batteries, do you use a smart charger when not driving? Or is this another silly suggestion that you will immediately rule out?

 

Cracked valve body:

xk8-cracked-gearbox-valve-body-zf-5hp24-151994/

 

Your battery has been brought up because of the codes that are intermittent that lead you to a possible low voltage confusing the TCM to the transmission valvebody. Aside from the codes the transmissions valvebody receives a command from the TCM that acts on the present condition of the engine via the ECM.

Now the transmission not engaging could be a number of things.

For example the shifter cable adjustment. This is a problem that many have experienced including me. The transmission would not upshift from first gear, out of gear or will not start. The shifter cable is mounted on the left side of the transmission and the linkage is internal to the shifter selector switch is mounted on the right. A slight difference in adjustment will cause shifting issues.

The valve body that is internal to the trans has a poor signal or one of the solenoids or pistons are malfunctioning or a crack.

The TCM is malfunctioning or you have an electrical cable issue or the ECM is not talking to the TCM or valvebody.

With the codes you are getting and the shifting issue I would first check the cable adjustment or the selector switch to see if it is loose or malfunctioning since you say the battery is good.

Since you say your problem is intermittent I would check the shifter cable adjustment and verify that the shifter selector switch is not malfunctioning.

Link http://jagrepair.com/images/TSB/307-01-1.pdf
Link http://jagrepair.com/images/TSB/XK8/307-01.pdf

This is my best guess based on your description. I am not a transmission guy only going by my past experience that forced me to better understand the transmission issues.

 

What has not been tried.
1. Batteries are good as was explained initially.
2. Fluid is at or very close to the proper level. Not enough miles on it to warrant a change either at the price of fluid.
3. Shifter linkage is tight and proper.
4. Throttle body checked and TPS checked and cleaned to see if it was realated to that.
5. TCM and ECU connections checked and cleaned
6. Vac hoses checked as well.


A valve body is useless as I don't have a shop willing to even put it in from their past bad experiences with ZF 5hp24s. The local shops will only do whole reman replacements. It isn't something I can do in my garage either. Also being that it is a summer of 96 build when I had it replaced they had to use my tranny since they couldn't come up with an early enough core. Sadly, I had a complete parts car from a deer incident a couple years ago that I didn't keep the tranny out of due to lack of space. Instead I keep the engine thinking now that the tranny should have been sorted keeping a factory replaced engine with 30k on the odo was more important then a bum tranny I shouldn't need for another 100k easy.

Gus, the tranny is engaging just fine just will "hold" its speed a bit when you let of the gas (almost like it isn't getting told there isn't gas (however if you drop it into neutral the rpms are right at that 600-750rpm mark) and it just overall is shifting weirdly.

 

Is the transmission up shifting properly and consistently?

 

Yeah, only thing I would say is sometimes it is faster going up then I remember it (but it goes thru the gears not skipping any of them). Zero banging or hard shifts, doesn't take its time going into gears like reverse or 1st when you first shift into 'em.

On the highway it almost seems like if you coast it will then when you give it gas it will go out of the torque lock but again it might just be me thinking too much about something it has always done.

 

So the driving and up shift is ok cold or hot? However, slow to go into first and reverse, is that only when the car is cold or warm?

Is down shifting ok?

The highway I do not understand.

 

No dif hot or cold, not slow to go into first or reverse at all (like you would get with a bad a drum).

Coming down in gears it is a little harsher than what I would think it was but not horrible, goes down thru all the gears as necessary.

If coasting at 70mph and then you lightly go on the gas it downshifts (or goes out of torque converter lock). That seems completely new or at least it makes more of a noticable thud when it does it (wouldn't call it a bang by any means. When it is acting up the shift are a bit harsher up and down, going uphill it almost feels like a carb car in too high of a gear if you know what that means just kind of a steady pulse where it won't go and again it will "hold speed" In other words you could go 25mph without touching the gas which is what causes the hard shifting esp down (almost like your trying to shift a stickshift without taking your foot entirely off the gas). None of it makes much sense to me.