Getrag 245 - Transmission FAQ and Install FAQ

[jgerry2002]

Introduction

Since I am on transmission number THREE in my tii, I figured I'd write up some of the many things I've learned about what to look for in a good used gearbox.

I've decided to start a FAQ on the Getrag 245. The most common transmission for use in a 5-speed conversion.

FYI, this gearbox is found on '80 to '82 320i's, it can be identified by its 3 piece case. Its a 242 4-speed with an extra section.

Ok, with another thread here --> http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,327269/highlight,getrag+245/

BMW lists production --> 09/1979 to 09/1982

Condition - What to look for

1) Make sure you bolt up a shifter plate and be sure the gearbox is able to select both neutral and 5th. I've had two transmissions get "stuck" and lock out gearing, or lose it suddenly while selecting reverse.

2) Make sure that in neutral the input shaft/output shaft spin freely

3) Make sure that in gear the transmission input/output spin in sequence

4) Check the existing fluid. Open up the fill plug first and smell the fluid. If it smells a little sweet and looks fairly clean consider yourself lucky. If the fluid has a burned smell or there is a metallic smell, then either the fluid has not been changed, or its of the wrong type (hypoid fluid is a NO NO).

5) Check the drain plug, some small filings are completely normal over time. Big chunks of gears are NOT Ok.

Seals - Replace them

1) Rear seal. Get a new rear seal and locking ring (or red loctite). You will likely need an air impact gun or you can probably change once its in the car. Do not forget the locking ring or loctite, if that nut backs off you can do some serious damage to both the transmission and related components

2) Front seal. Get a new front seal. You can use a bit of RTV (Loctite Gray works well) around the housing when you reinstall. Take your time to carefully retourque the bolts evenly.

3) Shifterseal. Get a new seal. You can try to remove the old one, or simply use a 1/2" pipe and push it inside the housing. There is room for a few seals without causing issues.

4) Speedometer seal is optional. Just a small o-ring if I remember correctly.

Part Numbers:

Front seal 23-11-1-228-314 (30mmx42mmx7mm)

Rear seal 23-12-1-205-340 (40mmx55mmx8mm)

Shifter seal 23121282394

Tranny output shaft locking ring 23-22-1-201-330

Speedometer seal (unsure here): 20 SHAFT SEAL (8X14X6) 23-12-1-490-192

O-RING 14,3X2,4X19,1 1 - 23-12-1-490-177

Other parts

1) You will most likely need to track down a 3 bolt flange to replace the 4 bolt flange found on most of these gearboxes. There is probably a later E21 or E30 part that would work, but I am unsure at this time.

Part Number --> 23 21 1 209 612

See PDF for manual here http://www.bmw2002.net/pdf/Getrag245.pdf I created of some scans downloaded from another FAQ member of the 320i manual.

Install - With the Motor in the car

I used a slightly modified version of Bill's method as listed on the FAQ --> http://www.bmw2002faq.com/content/view/90/32/

With the modified Bill FAQ method I was able to get my transmission to slide in rather easily in about 1.5 hours..most of that was trying to position the gearbox on the jack because I was installing the transmission BY MYSELF as my helper had to go to work!! I probably aligned and had the transmission "pop" in place after about 30 minutes of getting it up inside the car...

Read his method to start with in the FAQ section... then add these notes:

1) For the upper bolts, go with 10mm longer than stock M8x45mm.... then cut and slot the heads. Its long enough to line it up while its well outside the clutch/pilot bearing.

2) Use one LOWER bolt with the top cut M6x20. Stock length is fine.. I put one on the driver side of the motor

3) Polish that input shaft using some 100grit-600grit and use a very light lubricant on it. Make sure that you concentrate on the slight taper at the end, I made sure this was super smooth. FYI, I used Wurth HHS 2000 on the input shaft.

4) Use some lubricant (HHS 2000 again) on the clutch alignment tool... only a little is needed. Helps to get the pilot and clutch nice and slippery...

5) Put a piece of thin cardboard between the engine fan and radiator.

6) Take the distributor cap OFF or you might crack it against the firewall (ask me how I know).

7) Harbor Freight makes a very nice transmission jack with all sorts of adjustments. I bought it on special for $118

8) A regular floor jack is also helpful to move the tail of the transmission up inside

9) Take the shifter platform, and install the shifter mounts on the actual shifter platform, then put it up through the car and use a set of vice grips at the base to hold it up and inside the car. I used the two bolts to keep the fluid from leaking out the back. You can assemble this once it gets in the car prior to installing the transmission mount.

10) Go the very back of the the transmission once you get it lined up and lift it forward, my transmission popped right into place.

11) I used a little dab of synthetic wheel bearing grease on all contact points of the clutch release arm and the throwout bearing

Important Note!!!!

1) Wait 3 seconds before engaging reverse after running in a forward gear! This is actually noted in the E21 manual. It should not grind if you wait!

Comments??

[jgerock]

Justin -

Thanks for the great tips. I have some E21 245 trans and driveshaft spec pages I can send you that I found on the web - you may already have them.

I'm gathering the parts to convert my car over this winter. Need to buy all the seals first.

[jgerry2002]

Another idea here for making a tool to hold the flange while changing it out. I'm sure a 3 bolt version would require a bit more grinding, but would be doable as well.

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/p,644697/#644697

[nicktahoe]

Great thread and details. Any pics that might help along the way. I recently scored a Getrag 245 and am looking to do the same thing. Anything would help. Thanks again.