Planning a transmission rebuild and maybe engine rebuild
 

I had my trans repaired at about 65K miles and have had a small chirp when shifting under load ever since. I'm now at 107K and I'm considering sending the trans out for a full rebuild. I don't want to swap the trans as I'd prefer to keep the matching serial numbers on my E53.

Any referrals in Southern California? Also might just go ahead and do a full rebuild on my engine....any referrals there would also be appreciated.

What was the repair at 65k for?

I had taken it for a pretty brisk drive and when I got off the freeway, I was having an issue with slipping when shifting from 2-3 and 3-4. I'm not sure to this day what all they did to it...and now the shop is closed. I noticed the slight chirp about 6 months later. It only chirps when I'm really getting on it and winding it out. Under "normal" load there is no noise. It also won't chirp if I quickly release accelerator at the shift and mash it back to the floor. :D

I put a remanufactured tranny and torque converter in my E53 4.4i a few years ago from Euro Transmission Specialists. I had it shipped to Louisiana, but I seem to recall they are in LA (310 area code at any rate). I got an off the shelf one from them and sent them my core.

My transmission had been slipping for several years, starting at around 110k miles or so. Sport mode helped quite a bit for a while so we rode it until failure (it was my kids car at that point), which it did on my daughter one afternoon, conveniently a few blocks from my house.

I did some research and settled on Euro Transmission and have been pleased so far. No drama so far, going on three + years. The 4.6 gearbox is the same basic ZF model, but a bit different as it has an extra clutch and a different stall converter so I'd make sure they can get parts and rebuild yours. I spent some time looking for a 4.6 TQ for the engine swap I'm doing and they seem to be very hard to come by. That said, guys who have done the 4.6 swap into a 4.4 car (5 series or e53) will tell you that the car will run just fine with the 4.6 and the 4.4 ZF, in case you have to go with a 4.4 TQ for some reason.

https://eurotransspecialists.com/contact/

Thanks for all that info! I will reach out to them to see if they will rebuild it for me. I want to keep the matching serial numbers on this X5...I am going to fully restore it over the next year or two...although it's still in great shape I want it fully back to near new (except for my AMAZING BlueBus). :)