Hey guys so winter is over here and weather is getting to the point of being decent enough to start more xk8 projects(yay!!) two big port coming up are transmission oil and filter change, and then it’s on to new shocks and bushings all around. Let’s focus on the first one for now:
so last year I bought a kit to change the trans oil and filter, got a filter, pan gasket and 6liters of zf lifeguard, I then got the trans go pressure regulator valve repair kit as well based on advise from here, all of which is yet to be installed. My car has low miles, 69,000k so I’m doing this as preventative maintenance to avoid the dreaded drum failures as best as I can. It’s not an everyday driver either so I figured I’d start with the filter, pan gasket and fluid change, as well as the pressure regulator first, and see how it goes. Question is this, I remember when researching all this that the early xk8 trans oil pans had a smaller “headed” bolt verses the newer one, And heard/read/saw that they sometimes seize due to bing steel into aluminum. Anyone know the part number for the newer better ones, how many are needed and if they are direct replacements? Again I have 97 xk8 coupe with the zf 5hp trans, and based on all I’ve done so far to this car I would put any amount of money on that the trans fluid and filter have never been changed… I mean I changed out the “factory oem” fuel filter, did the timing chains and I still have the nikisil lined cylinder motor so yeah, trans is probably untouched as well. Thanks

 

My 97 drained out 3.5 litres and took 6.5 to fill so a well worth while job.
You can get torx with a larger size that fit.

 

All the bolts in my 1997 transmission pan at 75k miles came out easily for its first change and were used again. No corrosion problems at all.

Richard

 

^^ Mine did too, but some have had problems.

Give each of the bolts squirts of PB Blaster or whatever for a few days before you start the job. Make sure you use the correct T27 torx bit to remove them: T25 is more common, will fit, and is likely to strip the heads out. They were changed to T40 at some point.
A directional tap with a chisel on the edge of the head might help with any stubborn ones.

If you do need to replace any, they're just M6x22 cap screws, 22 of them in total.

 

I know the ZF 6HP26 gearbox superseded to T40 screws (from T27) but the ZF 5HP24 remained JLM888 (T27) as far as I know.

The JLM888 part NO superseded part number.

 

Thanks motorcarman.
That likely explains why I couldn't find any updates.

So, folks must have just started using the ones for the 6HP rather than a part change by ZF. They're slightly longer (M6x28.5), no doubt to accommodate the thicker flange on the plastic pan.

 

Ok thanks guys you have all collectively given me the info I needed. I believe I was mistaken about my initial thought of two bolt sizes for the older 5 speed trans, so thanks for the clarification. I’m eager to get back to working on this car and then drive the living $h1t out of it lol. I love this thing and won’t ever sell it, I’ve even been offered no joke four times what I paid for it and if I took it I could’ve bought at least two more, but I want THIS one. Thanks for all the help! Cheers