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Alternative Manual transmissions

E28 technical advice asked and given! Troubleshooting, modifications and more.
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Chrisso
Posts: 4
Joined: Feb 07, 2022 6:16 PM
Location: Sunshine Coast

Alternative Manual transmissions

Post by Chrisso »

Hi All,
New to the forum as now bringing my 86 535i back to life over here in Australia.
its an auto and i would very much like to eventually convert to manual, however trying to find a good used box is proving difficult and or v expensive.
So given the number of aftermarket transmission adapter plates that seem to be available (mainly for the 6 speed ZF auto) has anyone ever explored using a different manual gearbox. I've done the normal forum searches but cant find any references.
Cheers.
turbodan
Posts: 9366
Joined: Jan 09, 2007 10:19 PM

Re: Alternative Manual transmissions

Post by turbodan »

A tremec T5 or T56 could work with a custom bellhousing and driveshaft. Not a minor obstacle but it would be awesome to get a transmission in there that has aftermarket support.
 
Chrisso
Posts: 4
Joined: Feb 07, 2022 6:16 PM
Location: Sunshine Coast

Re: Alternative Manual transmissions

Post by Chrisso »

turbodan wrote: Jun 24, 2025 1:50 AM A tremec T5 or T56 could work with a custom bellhousing and driveshaft. Not a minor obstacle but it would be awesome to get a transmission in there that has aftermarket support.
 
 
 
Exactly!
The original manual 5 speeds are old, expensive and difficult to find here in Australia. And buying a second hand gearbox that may well be toast, that’s costs a not inconsiderable amount of cash, that I can’t get rebuilt doesn’t sound like a good idea to me.
Theres one 265/5 for sale here on the forum in the US and by the time I pay for shipping, if the seller would go the trouble of doing it for me, I’m probably looking at $5000 AU plus. 
Theres got to be a better long term solution, surely?
Galahad
Posts: 563
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: Alternative Manual transmissions

Post by Galahad »

just to throw some info out there - m20 and m5x engines have the same bell housing, just rotated a bit from each other. I know you have an m30 car, but if you're already looking at an adapter at least the shifter and driveshaft work would be easier
turbodan
Posts: 9366
Joined: Jan 09, 2007 10:19 PM

Re: Alternative Manual transmissions

Post by turbodan »

The m50--> gear ratios are not ideal. They took away the overdrive 5th and made it the same ratio as the 260/265 4th. Then the six speed came out with the old 5th gear ratio tacked on as 6th. Lot more rowing gears for the same cruising RPM. Don't tell the tens of thousands of guys that drive them daily, but those ratios kind of suck.

The tremec ratios look pretty good actually, especially for boost. Tall gears are great if you've got the power to pull them. 

 
helendamdam
Posts: 1
Joined: Jul 02, 2025 11:49 PM
Location: USA

Re: Alternative Manual transmissions

Post by helendamdam »

Chrisso wrote: Jun 23, 2025 11:20 PM Hi All,
New to the forum as now bringing my 86 535i back to life over here in Australia.
its an auto and i would very much like to eventually convert to geometry dash manual, however trying to find a  good used box is proving difficult and or v expensive.
So given the number of aftermarket transmission adapter plates that seem to be available (mainly for the 6 speed ZF auto) has anyone ever explored using a different manual gearbox. I've done the normal forum searches but cant find any references.
Cheers.
 
Have you looked into whether E28 535i-specific manual swap kits are available from companies like Metric Mechanic or others?
 
Chrisso
Posts: 4
Joined: Feb 07, 2022 6:16 PM
Location: Sunshine Coast

Re: Alternative Manual transmissions

Post by Chrisso »

Hi,
Yes as I said above by the time I’ve paid to ship the transmission it’s going to be prohibitively expensive. Looking at the prices from Metric Mechanic in US dollars, it’s not a good conversion to Australian dollars! 
i have contacted some companies here in Australia who make bellhousings for Tremec manual conversions but none could help. One thing I did find was quite a few companies offering adapter plates for M30 to zf 8 speed auto’s. This might be a good solution for me, have any of you guys heard of anyone fitting these to the e28? 
I’ve owned a few cars with the zf6 and driven a few with the 8 and whilst it’s not an old school manual it would certainly be easier to source. Cost wise it looks to be about the same as a locally sourced manual, if I could ever find one.
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