E24 getrag 6 Spd retrofit.

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
GazM3
Posts: 1791
Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

E24 getrag 6 Spd retrofit.

Post by GazM3 »

Hey chaps.
Been busy playing with my E34 so not much loving in the. past 18months for the E24. The clutch is getting tired and LSD losing its lsdness. I have an s50 based getrag 420g 6pd box and my original healthy 3.73lsd.

Was thinking of grafting the m88/3 (m30 based) bolt pattern to the bellousing so it bolts up without the use of a spacer. Can the 6spd physically fit in the trans tunnel without modification? I seem to recall someone in Sydney retrofitting the s38 based 6spd but can’t recall the details.

Any advice will be appreciated.
BMW’s
84 E24 M635csi
90 E34 M5 3.6
94 E34 540i/6 SC E85
97 E36 M3 euro SC U/C
97 Z3 2.8 widebody

OTHERS
11 Audi S5 3.0 SC
19 VW Amarok V6
VintageRacer
Posts: 87
Joined: Sat Jun 24, 2017 2:49 pm
Location: Waco, TX

Re: E24 getrag 6 Spd retrofit.

Post by VintageRacer »

Gaz. I have a design for an adapter that allows the use of a TKO based Tremec. It’s still a 5 speed though. It may be a lot less work than adapting the Later bmw stuff

The S38B38 came with a 6speed in the E34 M5. These are a very rare trans.
GazM3
Posts: 1791
Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

Re: E24 getrag 6 Spd retrofit.

Post by GazM3 »

Can’t see myself using a tremec. I like the ratios on the 420g and I have the 6cyl s50 version. I don’t thing it will be too hard once the bellhousing from a wrecked auto can be sought.
BMW’s
84 E24 M635csi
90 E34 M5 3.6
94 E34 540i/6 SC E85
97 E36 M3 euro SC U/C
97 Z3 2.8 widebody

OTHERS
11 Audi S5 3.0 SC
19 VW Amarok V6
VintageRacer
Posts: 87
Joined: Sat Jun 24, 2017 2:49 pm
Location: Waco, TX

Re: E24 getrag 6 Spd retrofit.

Post by VintageRacer »

Doesn’t the s50 share a bellhousing pattern with the smaller M20 series?

What about the T56? Several folks in Finland and Sweden have done that conversion. If you use an automatic Bell and a hydraulic throw out bearing from tilton that seems doable.
User avatar
slofut
Posts: 778
Joined: Thu May 30, 2013 1:29 am
Location: SW Ga

Re: E24 getrag 6 Spd retrofit.

Post by slofut »

That t56 is huge. I can't imagine it would go without major surgery but idk. Just put one in a C3 corvette, tight fit. I'll go check out the guys in Sweden, sounds interesting.

I stand corrected, it seems there is room in the e24 with a little massaging with a 3lb hammer. Still a big heavy trans behind a 200hp 6cyl though. Oh, and they're not that beefy either when stock. Mine needed a mainshaft, reverse and 4th gears, syncros and more.
'87 635csi, 5sp man, dk blu on pearl beige
'88 635csi, auto, black on grey
'63 BMW Isetta
'75 XJ6C, 2dr, warm 350
'86 XJ6, th700r4
'75TR6
'64 Olds 88 conv
"68 T120 Bonneville
GazM3
Posts: 1791
Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

Re: E24 getrag 6 Spd retrofit.

Post by GazM3 »

I can’t see myself using a t56. Ratios are all wrong for e24 with m88/3 and it would require a silly 4.45:1 diff which would make first and 2nd very short. Besides I have a t56 and it’s very agricultural to use compared with the 420s.

I have 2 other cars with 420s boxes and the change very nice. One is living behind 16psi of boosted e34 c/550-600bhp and is still very nice to use. If u do drag racing or lots of flat changing they don’t like it and fail. Lots of guys in Scandinavia seem to destroy them for some reason lol.
BMW’s
84 E24 M635csi
90 E34 M5 3.6
94 E34 540i/6 SC E85
97 E36 M3 euro SC U/C
97 Z3 2.8 widebody

OTHERS
11 Audi S5 3.0 SC
19 VW Amarok V6
Post Reply