Hello all, I have read several posts regarding the addition of transmission fluid on an XK8. The transmission cooling hose is apparently somewhere near the radiator, but I can't seem to locate it. Can I get a photo or diagram of what exactly it is I'm looking for? Thanks!

 

Tommy, not sure where that is. Mind if I ask what makes you think you need fluid?

John

 

For a few weeks now the transmission delays when engaging in forward or reverse, and sometimes there's a 'thump' when it does engage. The other day I got a transmission fault error. I have found several posts here on the forums about low transmission fluid, and it sounds like that's my issue.

 

The transmission on the earlier XK8 is the 5HP24 made by ZF in Germany. There is a WEALTH of information about these as they were used in many cars. These transmissions have a specific refill procedure that involve fluid dripping off of the refill port when the fluid reaches a temperature range. Running low or high on fluid is equally bad. This needs to be done correctly. There is no dip stick.

If you are stranded somewhere and need a refill NOW to get you home or to a shop, the trans cooler hose is on top of the radiator, driver side. The transmission fluid is cooled in the cold side of the radiator. Should be a big hex nut holding the aluminum pipe in place, near the top.

Just to tell you ahead of time, these transmissions suffer from a major design flaw, commonly referred to as the A-drum failure. It is believed to be a flaw in the valve body that, over time, applies too much pressure on the said drum, and literally shreds it to pieces. People more versed than me can chime in on your symptoms, but the diagnostics will likely start with reading the OBD codes with a Jaguar-aware scan tool.

Best of luck, keep us posted.

 

You can *hope* that it is low fluid, but likely A-drum failure.

Best to throw 1/2 a quart in to check first though. I am about to do my 6th A-drum replacement along with the valve upgrade next weekend- not too difficult.

 

Thanks Fred and Dee. I was just about to sell the car, and am hoping for a quick fix by adding transmission fluid. If it's an A-drum failure I guess I'm out of luck. There are no Jaguar mechanics within a few hundred miles of where I live, and I depend on a local mechanic to do routine maintenance and small repairs. Appreciate the help!

 

You do not need (or want) a Jaguar tech to do an A-drum failure repair. You just need a decent indie transmission shop that knows the ZF 5HP24 unit. Both flavors of ZF transmissions (the 5-speed in the pre-2003 cars and the 6-speed in the 2003-and-newer cars) were utilized in many different vehicle brands. Good, qualified indie shops can often handle these repairs....

 

Thanks Jon, I will look around for someone to work on that.

 

+1 on that. ZF were/are common on contemporary MB, BMW, Audi, Volvo models (to name a few). Fmertz has given you the correct ZF model number, wisely warned of an indiscriminate top-up, and with Jon, has given you a good explanation of the A=drum failure issue.

Suggest you find an auto trans shop that is familiar with European cars, check against the 5HP24 and get a quote for A-drum, full fluid change (Fred and many others are fans of Mercon ATF), filter pan etc . . . assuming you are not equipped to diy.

Best wishes,

Ken

 

Also change the main pressure valve to either the ZF upgrade or the transgo after market version.

http://www.jagrepair.com/images/Auto...%20ZF5HP24.pdf

 

Be very ware of removing the oil cooler hoses from the radiator, you can easily strip the threads off of the aluminium stub on the radiator.

You can easily end up with something like this meaning you need to replace the entire radiator.

 

Thanks for that important, time and money saving tip, RD!