1999 XJ8. Had been running perfect, then on backing up I felt a couple of thumps and the transmission now will not engage in forward or reverse. Nothing lit up on the instrument panel to indicate anything unusual.

Any ideas?

 

Try posting in the x308 forum. The transmission is different between the x350 and x308 models.
The five speed in the x308 is not as reliable as six speed in the later models. From your description it could be a broken gear.

 

1999 XJ8. Had been running perfect, 80K miles. Yesterday while backing up I felt a couple of thumps and the transmission now will not engage in forward or reverse. Nothing lit up on the instrument panel to indicate anything unusual. Is it a transmission, drive train, or other.

Anyone have a similar experience?

Any ideas?

Tom from Erie

 

I have had two transmission failures, but I could operate in 4th gear fwd (Limp home mode) and reverse. I also had fault lights as well.


Torque converter failure will give a hard shift.


Are you able to move the shift lever?


I fixed mine for $2600 including removal and install.

 

Tom,

I have moved your post from the forum for the X350 to the forum for the X308, which is the Jaguar factory project code for your 1999 XJ8. Here you will find knowledgeable owners of similar cars.

Cheers,

Don

 

Have you checked the linkage at the gearbox to make sure it is still connected?

 

I'm a recent X308 owner myself and reading up everything I can find...

Before incriminating the tranny (which I hear is pretty reliable) I would look in the differential since they are weaker than previous models and its been reported that crownwheel /pinion teeth sheering off. If I'm right it should be easier on your wallet. If not at least you'll have that possibility eliminated...
Good luck and please report back
Alex

 

The XJR has a much more reliable transmission than the XJ8. If the rest
of the car is ok, it is worth fixing. You Tube has a video of guys
overhauling the ZF 5HP24 in his living room.


This table lists which transmission are in the various cars.
EnginePowerTorqueTransmission
3.2 L240 bhp (179 kW; 243 PS)233 lb·ft (316 N·m)ZF 5HP24
4.0 L290 bhp (216 kW; 294 PS)290 lb·ft (390 N·m)ZF 5HP24
4.0 L supercharged370 bhp (276 kW; 375 PS)387 lb·ft (525 N·m)Mercedes-Benz 5G-Tronic W5A580

 

Start the car and put in drive. Gently increase revs, if it engages with a THUMP, then you have a broken A drum in the transmission. This is a known fault and can be fixed relatively cheaply and easily.