Picked up a used 44k mile trans for my 600awhp 335xi. Need help refreshing it

zmon1300

Corporal
Nov 3, 2016
181
114
0
Chicagoland
Ride
'10 335xi
Hey guys,

My current trans on my 93k mile 335xi does not hold 5th gear anymore. I abused that trans for about 50k miles. It was either on Alpina flash or xHP stg3 OTS tune. I recently picked up a 44k mile trans from a local part out and got a trans cooler core and lines. I wanted to ask what things I need to do to refresh it make it ready for 600awhp?

I did some researching and came up with the following things that I should replace:
Trans pan/filter
trans pan/filter gasket
Trans oil
Mechatronic sleeve]
Sonax Zip Kit

Are there any other things I should replace to get it ready for my car? Also, what trans fluid would be best in this case? What kind of inline T-stat should I get for the trans cooler?

Thanks
Z
 

zmon1300

Corporal
Nov 3, 2016
181
114
0
Chicagoland
Ride
'10 335xi
my shop has been slammed. have not gotten a chance to install the trans....It sucks not being able to hold 5th gear so I have been refraining from going wot into 5th. I just let off slightly and itll go into 5th no problem then i can get back on the gas. it sucks in a close race, but gotta deal with it, till i get the call from the shop. I picked up a new pan, filter, gasket, zip kit, aluminum mech adapter, and some redline d4. everything is ready for the install. will document it on my thread once the car is under the knife. Got a bunch new upgraded suspension parts going on too so car should be fun to throw into corners also. Will post updates once it gets on a lift.

Z
 
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Cheezy

Lieutenant
Nov 7, 2016
611
225
0
Toledo Ohio
My trans does the same thing! Lol I'm trying to get this 60k trans instead of going straight for the PD rebuild right now. What's the zip kit?
 

Bavkingn54

Lurker
Sep 13, 2018
16
5
0
Mass-RI
Ride
09 bmw 335i xdrive
My trans does the same thing! Lol I'm trying to get this 60k trans instead of going straight for the PD rebuild right now. What's the zip kit?
The zip kit is a rebuild kit for valvebody and will tighten up shift quality. @zmon1300 you will also need the seperator plate I do not believe it comes with zip kit. It's the plate that goes between both halves of the valvebody.