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Subject: Finally replaced transmission and rear main seal Author: Beamer23 : member since January, 2007 : 1034 posts Posted on: 2011-10-20 17:18:44

My transmission was giving me intermittent problems after driving for about 2 hours. Basically reverse was hesitating. Got it checked out by an expert and was told I had two options: new valve body or used transmission. While we looked under the car, we saw the rear main seal was leaking a little so I decided -2 birds one stone- & went with a used transmission. I didn't want to do a full writeup because there are good ones on e38.org already.

Here are my notes on this project:
-About 8 hours, even with the help of a friend who's an experienced mechanic. 2 people are required.
-You will probably strip the exhaust bolts (atleast)
-The four bolts at the top of the transmission are the hardest to take off. Need a long (very long) extention to reach them. Takes time and finesse.
-To remove the (4) torque converter bolts from the engine, you have to manually turn the crankshaft to gain access to the first t/c bolt. Then turn again for second bolt. etc.
-Keep a blow torch handy when a bolt won't budge.

The weirdest part was when we hooked car up to DIS and noticed that the transmission temp showed as 40°C (approx 105°F) eventhough the transmission was stone cold (with new oil inside). I guess that's normal? TIS says the temp should be between 30°C-50°C so we filled her up using the instructions. After running the car through the gears (with AC on) we refilled it. Then we waited for the temp to drop from 52°C to 45°C. If I remmeber correctly, it took about 1 hour to go down to 45°C. Then added a little more and closed her up. 10 Qts in total.

Test drove it for about 700miles now and very smooth so far. Next step is to update transmission software.

Replacement Parts:
OEM oil (in my case 10 qts)
OEM Filter 24341422419 & O-Ring 24341422152
Pan gasket 24111422676 (5HP24 transmission A5S440Z) -My dealer gave me the one for the 5HP30.
input shaft seal 24311422671
output shaft seal 24201422521
rear main seal 11141710247
Transmission mounts (Don't forget these like I did) 22316771130 (need 2)

Donor car had about 84k on it and from the looks of it very well taken car of before the accident.

New Transmission and TC.



Valvebody and oil looks pretty clean



New filter goes in after a thorough cleaning



Transmission had been sitting for a month or two. Although there's some dirt, I was happy to see there was No metal on any of the magnets. Very good sign



Closeup of the magnet. Coudn't feel any metal on them at all!



Nice and clean



Change out the input shaft seal



Old seal



Finally the exhaust comes off. Stripped some mounting bolts in the process so its a good idea to keep spare ones around. Ended up changing all the bolts with new ones.



You can see the rear main seal was leaking a bit. Hadn't noticed any drops in my driveway so I guess the seal failed recently.





Driveshaft came off pretty easily



Unbolted the transmission bell housing and 4 torque converter bolts. Finally time to take it down




Fly wheel in the way of the rear main seal.


The rear main seal Finally goes in!



Old seal vs new. Didn't notice any cracks so I guess it was warped or shrank.



Donor transmission finally goes in



Exhaust and heatshield installed



I decided to keep the old transmission around for a few months incase this one gave me issuses but afer test driving for about 700 miles now..so far so good. Feels as smooth as the old one




2000 740iA

• Finally replaced transmission and rear main seal (pic) - Beamer23 2011-10-20 17:18:44 (6243 views)
  • Good job. Been there, done that without helper. (nt) - davidf 2011-10-21 11:03:48 (4501 views)
    • Same Here.. (nt) - Chief Jimbo 2011-10-21 14:33:05 (96 views)
  • Way to go. Great pics. Well done! (nt) - aaron00740il 2011-10-20 19:02:58 (602 views)
  • Just EPIC!..Congrats!!!!!...Love successful stories like so (nt) - snitch740i 2011-10-20 18:49:50 (94 views)
  • Glad you got it done!! Great job on the write up and pictures.. (nt) - Chief Jimbo 2011-10-20 17:32:43 (105 views)
  • Big job - well done. Impressive. (nt) - RobinK 2011-10-20 17:32:36 (96 views)