5-speed tranny support question?

[jjs2800cs]

Just finishing a 5-speed conversion on a 1970 2800CS, was a 4 speed. Tranny and support is from a 528i (E12). The Getrag has two mounting "ears". Just like my old 4-speed only the right side looks to be used.

Is there any reason why we can not also use the left ear. I plan on using an identical rubber mount as used on the right side and attaching it to the support beam via a custom made spacer. Thus the motor and tranny will be supported in 4 spots instead of 3.

Is there any reason not to do this? It seems that there might be a lot of stress on the right ear support in the stock configuration.

Opinions?

Thanks

jjs2800CS

 

[Chamonix_E9]

I have a dual rubber support made out of aluminum for the 5-speed 265 in my car. I have no idea what car it came from as the box with support came from an E9 CS that was converted to 5-speed earlier in its life.
The donor must have been E12, E24 or E28 but I have never seen it on other models. The support only has two mounting holes to the body, like the pressed steel ones.
One day I may make a picture and post it here.

I do like having dual support there, not that it's relevant for this situation but I once owned a BMW 2000 automatic that had its single rear mount fail. The guibo managed to grab the gearbox control rod when I went through a RH corner. The rod wrapped around the driveshaft which pulled the box right into park while going at a good rate of speed. An interesting experience.

 

[franticfam]

5 speed tranny support

"I have a dual rubber support made out of aluminum for the 5-speed 265 in my car. I have no idea what car it came from..."

That sounds a lot like the tranny support from an E30 M3.- Jim

 

[John Buchtenkirch]

I also have the aluminum twin mount cross-member. SF Don says they are known for breaking ---- does anyone know if there is an identical twin mount cross-member available in a steel stamping ? I like the twin mount and it leaves the rear mount on the 265 Getrag open for hanging the exhaust system. John Buchtenkirch

 

[jjs2800cs]

Thanks to all so far for the replies. I used a stock stamped steel support form an E12. As the attached photo shows we added an identical rubber mount to the left "ear" and made a makeshift spacer down to the steel support. I plan on making something more stout giving better bearing support if all agree there is no problem using the left ear. Certainly my spacer is better than nothing at all.

Also as is evident we had to make a way to attach the steel bar to the car frame pickups as using the E12 steel bar lines up exactly where the t-nuts slide into the supports and there was no way to attach it.

Nothing is ever easy. Should have the car on the road for a test drive this weekend.

Thanks

jjs2800cs

 

[frogisland]

My aluminium one came from an early e28 535, they are also on the e24. There are a couple of part numbers but have not been able to determine what the differences are. The last photo shows one that has been reinforced. Mine is due to have the ends cut off also and new pieces welded on with twin mountings.

 

[John Buchtenkirch]

Also as is evident we had to make a way to attach the steel bar to the car frame pickups as using the E12 steel bar lines up exactly where the t-nuts slide into the supports and there was no way to attach it.

I made up ¼” plates with a stud for the cross-member and holes for the T-bolts in front & behind the cross-member so now I have a pair of T-bolts on each side holding up the transmission. Being the cross-member is dropped ¼” I had to put ¼” thick washers under the mounts to space them back up. If nothing turns up from BMW, I’ll fabricate a proper steel one but this will do for now. ~ John Buchtenkirch

 

[Jan Gullett]

Tranny support

Metric Mechanic has a dual support that is very firm and heavy steel. I used to have one. It was tight but I had some drive line vibration for my 3.5 liter when the guibo was older. Switched to the e12 setup and haven't looked back. But the heavier setup would be better in racing and sport applications I suspect.

 

[KHB]

5spd with Early Style Bell Housing?

I thought the 5spd was not compatible with this bell housing. Am I wrong or is there a way to make it work?

Thanks,

 

[jjs2800cs]

KHB

The bellhousing was also replaced from an E12 and used a newer slave cylinder setup. Old 4-speed belhousing had different mounting system.

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Update on progress, car is running with the 5 speed and has entirely different shift feel than the old ZF 4-speed, very positive as the replacement tranny was in great condition. The ability now to shift into 5th is great.

Thanks to all who replied to my various questions during the conversion.

jjs2800CS