Hi all. I have an 01 XK8 with 170k on it. Recently I’ve noticed that if I come to a stop on an uphill incline I feel a jolt that seems to come from the back end when I move off. I initially had it checked thinking it may have been a rear universal joint but inspection by a mech says no and appears to be no other issue in the rear, is this a transmission issue? Car runs smoothly through all gears while accelerating, its been suggested that it might be something called a parking pawl, anyone had this issue and know it it is likely to cause a catastrophic trans failure. Any thoughts on this appreciated.

 

When you come to a stop are you putting the trans in P and letting off the brakes?

If parked on an incline, the parking pawl in the transmission is holding the weight of the car and will often “pop” out when you shift to D. Best strategy here is to come to a stop, set the handbrake, put the car in N then let off the brakes to ensure the weight is being held by the handbrake. After that move to P and there will be no load on the transmission due to the incline.

 

What you have, more than likely is a sticking valve within the transmission. If you dont get it fixed immediately you may end up wrecking the 1st gear clutch basket ("A drum"). Fixing the valve does not require transmission removal but if the A drum fails, it will require a complete rebuild if the fragments don't wreck your valve body. Trust me from experience! There is an excelent YouTube video on this very subject.

 

Thanks for the reply, not so much in park, say coming up hill to a stop sign, stopping release foot from break and move off, that’s when I will experience that kick, I’ve found if I use two feet and ease of the brake while applying acceleration I can avoid that jolt. On a slight incline no issue, on a flat no issue. Another member has suggested a sticky valve, however I don’t think draining the fluid to get at it is a good idea on this trans, I purchased with 150k on it and service history shows no record of work on trans. My local mech says draining my do more harm than good.

 

Fresh ATF is far more likely to improve your transmission rather than harming it....

 

I agree with Jon89. I can see no harm what so ever in, at the very least, changing the filter and fluid. Ensuring that you get the right amount of fluid in the trans is another issue since there is no dip stick. Check other transmission posts for proper filling if your mechanic is not famliar.

 

I hate to keep at it but, 155000 is when my transmission started acting up. I didn't know any better because I had just got the car and continued to drive it until I blew up the A drum. I am a mechanic and I pulled the transmission and repaired it myself. Thanks to the above videos. It was still pretty expensive and time conssuming because I did it all solo. Performing this minor maintenance may get you many more miles while you start saving for a reuild. Good luck.

 

Thanks for the info, not quite clear if that procedure calls for the fluid to de drained, my local tech says that’s not a good idea as there my be many particles that may be filling in small gaps, I’m good with the engine but the trans is a mystery to me.

 

Probably most of the members who have been around for years have drained and filled 2-3 times and changed the filter. Many with the 5HP25 have replaced the main pressure valve with the ZF upgrade or Trans Go kit.

A trans. flush may be a risky process, but I think your tech is wrong about the drain and fill. However, he is probably thinking that if he does it and then the transmission fails, he will be blamed.