Engine or transmission problems that aren't corrected quite often lead to much more costly issues. I would visit a well recommended independent transmission shop familiar with BMW transmission for a diagnosis.

Do as CleanIsFast suggests. Come to a complete stop everytime you drive it. Or manually shift and leave stop signs in second gear. Either way you will not experience the rear ended feel. I had the same problem in the last X5 I had. Sold it to my brother in law under instructions to drive it the way I described... no problems since.

I also used to experience a delay when shifting into reverse. I think that is also fairly common when experiencing the "kick in the rear" problem. I believe solenoids fixed the issue for a couple of people on the forums. I'll try solenoids first before buying a whole transmission if the 4.8is ever experiences an issue. :thumbup:

When you changed your trans fluid you used about 7 liters? I recall that when I did the flush on mine it was close to 13L due to the TC.

Yes it took a lot, at least 7L to 8L

I replaced the transmission valve body and did not have any issues with this for the rest of the time I owned the vehicle. I think the cost of the part was $2,300 from BMW however my indy picked it up directly from the distributor for $550. This was on my 2000 4.4.

It's just very hard to pinpoint what is exactly wrong. Some people say a fluid/filter changed cured, others say wire harness replacement, solenoids, complete torque converter replacement, complete transmission replacement, valve body megatronic, aftermarket oil coolers, etc

Most people just replace the entire transmission because it has new components of everything listed above (minus the aftermarket cooler). Pay once and it's all over with or risk trying to replace one item and hope for the best. It's tough because you have to pretty much drain the fluid out to do anything, and the fluid is expensive as-is.

I'm surprised that after all of these years and the number of occurrences that a common cause has not been identified. Surely this one problem can't be problems which were addressed by these fixes.

Might try to PM to RRPhil. I think he is the best here as it relates to transmission problems.

Yes RRPhil would be the best resource especially on the rebuild side. Pitty he is not in the US

Yesterday I took the 4.6 for a nice long (& spirited drive). What a machine....I eventually tried sport mode with manual shifting. This is the first time I've summed up the courage to try the manual shifting and to my surprise, it shifted flawless with no slipping, noises, etc from 1-2-3-4-5 and back down. Wondering If I just drive this way all the time and when coming to a stop just leave it in 2nd and see if the downshift lurch stays away.