Hey Jag people - I have a 2006 XK8 with the 6-speed transmission. the shifts are a bit jerky and it kind of clunks downshifting into first when coming to a stop. A jag dealer (used, not factory) I know suggested a fluid flush and new fluid and then a re-flash of the computers to re-set the trans. I understand the fluid change, but is anyone familiar with the re-flash? I understand a dealer has to do that, but is it effective? Thanks for any help!

 

Your shop is correct. Change the fluid, DO NOT FLUSH! Then have the trans reflashed.

 

my 03 did this at 98k with no history of trans work. Just do the trans flush, get as much out as your can, fluid. Let it sit over night and drip as much as possible. That is what I was told to day. After the flush and new filter using the correct trans fluid mine returned to fine shifting. Some have had to do this fluid change twice if your car has miles, lack of care, in a dirty area of town. DON'T do any trans re flashing or the like. The TSB for my says to do the flush first before doing anything.

 

My recent experience was due to low/leaking trans fluid. I'd make sure you don't have a leak before flushing. Leak was at lower trans line at radiator. Once mine was fixed and topped off it runs fine with no reflash.

 

I probably should have said change the fluid and then reflash if necc. I will still say DO NOT flush, just drain and refill. Never heard that because you live in a "dirty part of town" you should change the fluid? In my experience flushing can stir up residue and might cause issues because flushing is done under pressure. Just change the fluid/ filter.

 

If you are unsure of the history, you would do well by doing a more comprehensive maintenance cycle. Do a drain and refill (seriously consider MERCON SP, cheap and available everywhere), replace the pan (and its integrated filter), replace the connector sleeve (even if it does not leak), even consider dropping the valve body and replace the bridge seal (a bit more involved, but it is the right time to do it). This is all done from the bottom of the transmission, no need to take it off.

There are several sources for parts, from original ZF to aftermarket on eBay (WAY cheaper).

Once all of this is taken care of, do a test drive and see if any of the symptoms persist. If they do, have the transmission adaptations reset. This is done with the factory software, and could be accompanied by a software update/reflash. The dealer is an option, but there are others.

Best of luck, keep us posted.

 

^^ What Fred said....

 

Thanks all! Will get on this as soon as the trans is finished being replaced in my X308 VDP (It's been a long week!)