auto diff or manual diff?

[DimenX]

I currently have a 325i auto with LSD differential (dont know the ratio) and i´m in progress of swaping to manual tranny, do I swap the diff too or the auto diff is ok or better ?

The manual tranny comes from a 318is 1994

Thanks.

[PHARMDVIPER]

you are using a tranny from a 318?...will it even fit?

[espguitarist]

I currently have a 325i auto with LSD differential (dont know the ratio) and i´m in progress of swaping to manual tranny, do I swap the diff too or the auto diff is ok or better ?

The manual tranny comes from a 318is 1994

Thanks.

The diff in your auto will be a 3.91. You can use it with the manual transmission, but your first gear will be VERY short and you will be running about 3500 - 4000 rpms at highway speeds in 5th. I would recommend getting a 3.23 or 3.38 LSD if you can afford it, if not you should probably go with a 3.15.


you are using a tranny from a 318?...will it even fit?

Yes it'll fit. Not the best idea though...

OP, you need to read this as well.

http://forums.bimmerforums.com/forum/showpost.php?p=16786262&postcount=1764

[RatFink328]

Is there a listing resource somewhere of what diff ratios came with what transmissions? Not to thread-jack, but I cant seem to find out what rear end i have. The tag on my diff is gone (of course, nothing is simple, is it?), but I SHOULD have a 2.93 open since I have an auto trans. But when I do the spin test, one wheel spins forward and the other backwards, just like a limited slip rear end. Any other suggestions on how to figure out what ratio I have?

[espguitarist]

Is there a listing resource somewhere of what diff ratios came with what transmissions? Not to thread-jack, but I cant seem to find out what rear end i have. The tag on my diff is gone (of course, nothing is simple, is it?), but I SHOULD have a 2.93 open since I have an auto trans. But when I do the spin test, one wheel spins forward and the other backwards, just like a limited slip rear end. Any other suggestions on how to figure out what ratio I have?

Have the dealer look it up. It's really the only way to tell. I don't think a 2.93 was ever in an automatic though, I'm pretty sure MOST of the E36 automatics were paired up with 3.91s. Here's what I know -

MOST Manual M3s had 3.23 or 3.38 LSD
Automatic M3s I'm not sure
MOST Manual 325/328 had 3.15, LSD depended on options and packages
Automatic 325/328 had 3.91, LSD depended on options and packages

No idea with the 318s, although I think the manuals had 3.15.

Don't quote me on any of this, all of this info is just from what I've seen. There are ratios for the E36 from 2.93 up to 4.10, and possibly more but I have no idea where any of them fit in.

[328istothebone]

LSD makes both wheels go forward when one is spun, not one forward and one backwards like previously stated in this thread.

[flyfishvt]

Ok Ive been looking for a replacement trans for my getrag 95 325 coupe M50 engine. I have a chance to get a ZF from a 97 328. Its not listed as an exact replacement. I think its because the gear ratios are different. I need a difinitive answer on will this fit/work or not. Anyone?

[espguitarist]

Ok Ive been looking for a replacement trans for my getrag 95 325 coupe M50 engine. I have a chance to get a ZF from a 97 328. Its not listed as an exact replacement. I think its because the gear ratios are different. I need a difinitive answer on will this fit/work or not. Anyone?

Yes.

[flyfishvt]

Thanks you just saved me $100!!!!!! Stop by the house and have a Bass Ale on me.

[DimenX]

thread jackers!! joking :P

I'm getting the 318 manual tranny full with differential. Just wondering which would be best. Most time I drive in city with traffic jam

[blackbimma]

I don't know what the 318 diff is, but I think the 3.91 that comes with the automatics is great with the manual after you do the swap if you don't do a lot of highway driving. In your 0-60 you'll have to make a 2-3 shift, and first is kinda short, but the car will have a lot of torque in just about every gear. I've accidently hit the rev limiter a few times before my 1-2 shift because it revs so fast. 1st will redline at about 35mph and it gets there quick with the 3.91.

Just try it and see if you like it. If not you can always swap it later.

[espguitarist]

Thanks you just saved me $100!!!!!! Stop by the house and have a Bass Ale on me.

You're welcome. I'd love to stop by for a beer if I lived in Vermont and wasn't 17. :rofl


thread jackers!! joking :P

I'm getting the 318 manual tranny full with differential. Just wondering which would be best. Most time I drive in city with traffic jam

Like I said before, I'll work if you get all the components from the 318, but keep in mind that even though it is still technically a Getrag S5D 250G it still has a different part number between 6 cylinder and 4 cylinder cars. I went through the same thing you did and I actually ended up with a 318 driveline installed in my car before I realized it and THEN had to take it all out and do it over because I didn't want to risk the transmission failing prematurely.


I don't know what the 318 diff is, but I think the 3.91 that comes with the automatics is great with the manual after you do the swap if you don't do a lot of highway driving. In your 0-60 you'll have to make a 2-3 shift, and first is kinda short, but the car will have a lot of torque in just about every gear. I've accidently hit the rev limiter a few times before my 1-2 shift because it revs so fast. 1st will redline at about 35mph and it gets there quick with the 3.91.

Just try it and see if you like it. If not you can always swap it later.

The 318 manuals came with the 3.15. I wish I could have put my 3.91 in my car just to see what it was like, but I also had to relearn how to drive manual on this car, so I didn't want to deal with a short 1st gear.

However (to the OP)...the 3.91 from your automatic 325i WILL NOT WORK with the driveshaft from the 318. The driveshafts from the 318 and 325 are different lengths.

[thedude60126]

Had a 3.91 LSD in my car for a while and just know your gonna get great torques but no first pretty much and will be doing 4500 rpms' at 70. Just went to a 3.23 LSD