Hey everyone this is only my second time posting in this forum but anyways I have a 99 XJ8 with 92k miles on it and ive been noticing the past few months that when i push down completely on the accelerator and the car begins to shift from 1st gear into 2nd the car stops accelerating but the rpms go up by about 1k then it gets into second gear and jolts me back and begins to accelerate and shift normally again. Ive talked to a few people some said it might be the solenoid, and I also had the fluid flushed (helped minisculely), other people say I should start looking for a new transmission. I was just thinking about taking it into my local Jaguar dealership to have it looked at but I figured it would be wise to see some other opinions on what the problem may be.

Thanks!

 

I have a 98 VDP. The car is equipped with a ZF Transmission. The transmissions have a known manufactures defect. Front drum cracked. Unfortunately I needed a full rebuild as most of the gears were also shot. I think it has something to do with the front drum cracking.

For me the specialty transmission shop was on top of it. They verified their findings by taking out the tranny for inspection. Didn't surprise them and they also knew how to rebuild it and re-install in 3 days. Out for inspection and parts ordered 1 day, rebuild 1 day and it was ready the 3 rd day before 3 pm.

The mechanic of shop told me there is an after market part used now for a long time and is holding up fine.

I also took advantage of the transmission being out and installed a new tongue converter.

Please don't miss understand me, I am not diagnosing your symptoms, just telling you what I did. A bit nerve racking of course .... shes great now! And worth every penny.

My symptoms were more from a start off I couldn't go into next gears and a loud "thump" was heard from N to 1st by increasing RPM.

I hope your situation works out in your favor so you can enjoy MORE rides!

 

They are well known for issues. I posted a rebuild thread, search under my username for "threads started by avt007" and you'll find it. There are a LOT of other threads, search for 5HP24.
KillerKat, yours is not a Mercedes transmission, those were only in the XJR and XKR. Yours is the ZF 5HP24, also used by BMW and Audi.

 

Thanks, your right ZF, must of been thinking of buying one? Thanks for the correction. I made the correction above.

 

Thanks ill look into it more

 

my transmission shifts perfectly up but will not shift back down.
only after killing the engine will it go back to 1.
anybody has any experience like it and knows what to do?

 

That may be an electronic issue. First try a hard reset by disconnecting the neg. battery cable and touching it briefly to the positive terminal.
If that doesn't work have the codes read by an independent Jag shop, or dealer if you can't find one. The transmission module may be faulty. A used one is not expensive.
If your problem continues, start a new thread with the title 'Transmission will not downshift' as your issue is totally different from the one in this thread.
When you have time, please visit the new member area and introduce yourself and your car:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Have you made any progress on your problem? There are many people here willing to help.

 

no not yet. the jag was my late fiance's dream and back than i could afford to get it for him. after i had the problem with the shifting and overheating i just have it sit in my driveway for over 2 years. now i am trying to get it back on the road. ty so much for trying to help

 

1999 XJ8 90K miles. Runs fine, shifted fine. Car came home, was parked, went out, it starts but will not shift. Shifter moves, lights indicate position. Checked under car, cable intact. Took apart J Gate, checked connections, all is well. Checked codes, no codes. Had P1722 code at first, (slippage) erased it, has not come back. Transmission light is not on. To me this sounds like low fluid. Anyone agree? I have lots of experience with Jags, this is my first XJ8. ZF5HP24 box I guess. Cheers,
Zaphod

 

I would check fluid level first. Are you leaking fluid anywhere? If that is ok try revving the engine a little to see if it will go into gear.

You should start your own thread.

 

answered my own question. Only about 2 quarts drained. I think it has a front seal leak. Going to change the filter and throw in some Bar's leaks with the refill and see what happens.
Cheers,
Zaphod

 

I would avoid adding any kind of stop leak to any part of a car at any time with an exception of being stranded in a desolate location with no means of contact to anyone. All stop leak stuff is bad.

 

Yeah, I hear you. Jaguar used to ship XJS models with bars leaks in them from the factory. The transmission fluid they want you to buy has a seal softener in it, so I'm going with full synthetic and a seal softener. Cheers,