Transmission choices?

[Knockenwelle]

These transmissions love MTL. It's a MUCH superior oil on paper for the application, and works better in a trans with some mileage. Its viscosity rating is an SAE 70, but it actually flows about the same as ATF. Like the man said, it's what the doctor ordered.

[ScottL]

You can run any of a number of rear-drive racing transmissions in an E30. Pick one to match the torque and horsepower of the motor and have at it. Dog ring, straight cut, sequential... they all come without bell housings so it's a matter of sourcing a housing to mate with the motor, getting the input shaft dimensions right, choosing a clutch, and mating the output with a drive shaft. Obviously, some shifter work might be needed too....

[Dyno4mance]

Thanks for the info Steve and thanks for the spin in your car yesterday....really enjoyed driving a 325i for the first time....

[Stevie30]

Andrew, I found this:


Synthetic Manual Transmission Lubricants
Red Line Oil's MTL and MT-90 are designed to provide excellent protection and improved shiftability for manual transmissions and transaxles, having cured the problem of hard shifting in thousands of transmissions with shifting troubles. How? They have the appropriate coefficient of friction for most manual transmission synchronizers (many gear oils, engine oils, and ATFs are too slippery for proper synchro engagement). And, the wide viscosity of MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL. The shear stability and oxidation stability of these products are excellent, thus the physical characteristics of Red Line MTL and MT-90 will change little with use.

[Dyno4mance]

What wieght is RL MTL?...Is it 75/90?

[nando]

yeah mine is a green sticker with over 250k, and I run MTL

[gearheadE30]

iirc some have an orange sticker and others have a green stocker. Green sticker ones were supposed to have ATF. It makes more sense to run MTL though.

[nando]

MTL? I was under the impression these cars trans called for ATF, have to double check the Bentley though.

it doesn't matter. Apparently the only reason some of them came with ATF was to save money. Why keep two types of fluids at your factory (to the tune of millions of gallons) if you can get away with using only one?

my G260 originally came with ATF (~220k). Been running Redline MTL in it for the last 30k, it's been just fine. Personally I would rather run MTL regardless of what the OEM says, ATF just isn't as good of a lubricant.

[e30_325es]

The fluid depends on what transmission label you have (260's), but the zf's take atf.

[asubimmer]

MTL? I was under the impression these cars trans called for ATF, have to double check the Bentley though.

yeah they do but I always ran MTL in mine. Its what the doc called for :-D

[z31maniac]

MTL? I was under the impression these cars trans called for ATF, have to double check the Bentley though.

[Knockenwelle]

I'm using a Getrag 240 from a late 318iS. The ratios are a bit closer, as well as having a lower (numerically) first gear. The only fitment problem is that it is rotated 10 degrees relative to the block, so it sits a bit twisted in the car making custom shift linkage and mounts necessary. It IS technically a bit weaker than the 260, but behind your M20, it will last quite a while unless abused stupidly--this does not include track use. Fill it with MTL and go. Mine came out of a 90k-mile donor, and has performed great so far. It's also about 10 lbs lighter.

[z31maniac]

^The 6speed does work with a custom driveshaft.

BierBrenner, has a How To thread on getting a 6spd in an E30.

[gearheadE30]

Metric mechanic trannies will probably offer the best track longevity of the stock-ish options given the work they put into the parts.

As for the 6 speed, it should work with a custom driveshaft, among other things. Since the 260 bolts to an M50 fine, albeit at an angle, it would make sense that the reverse is true as well.

[Dyno4mance]

e46 6 speed? e36 m3 5 speed zf?

Will the e36 tranny fit the M20?...any idea of the gear ratios in that tranny?