THSCC Forums

Alright so my new to me BMW 318is is in the garage getting ready for paint. Instead of parting what I needed together I went and bought myself a Parts car. It's a 88 325i automatic. Long story short, my rearend is whining and clunking like crazy and I'm not sure it's got to much servicable life left. The seals leak and I'd bet at some point in it's life it was 'run dry'. My parts car has a 4.10 LSD but in a medium case. Is the bigger case really worth it in a car that only makes 110 to 115 whp? I'm gunna run the car in DSP so I've got a large power gap to overcome(let alone my wallet gap to others running in NC). A bigger unit would hurt me alot, especially if it's alot heavier than the smaller unit. Something like 40 pounds from what I've read so far. This is my first RWD I've ever actually done work on. So How would a swap of rearends go, is it a simple bolt on?

Edit: If however the heavier unit would make my car more reliable to me it'd be worth the weight. If the smaller unit requires a degree of finesse to last I'd prefer to pitch it for the beefy rearend. I want the car to be tough enough to be able to do doughnuts, burnouts, powerslides, hitting the limiter, etc without hurting it.

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2006 Civic Si - #24 HS for 2015

2005 GMC Sierra
1991 318is Garage Ornament

My 2003 rule book is dated, but there are no 6 cylinder E30 BMW's listed on the same line as 4 cylinder BMW's, so it seems your swap is not legal at all (or wasn't in 2003). Maybe the 2004 rule book is different, or maybe it's been covered in a FasTrack?

Scott

Yeah I am not sure on this one. The 91 318is uses a completely different 4cly than all other yr E30's. Its the M42 that came in the E36's.

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91 Jetta GLI STS/DSP 111
85 Porsche 944 ASP 11
http://www.blackforestindustries.com

Yup, the M42 was offered only in the '91 318's. Now, the automatic 318i didn't use a 4.10 rear end like the 318is, I want to say it was a 3.73, but they never made an LSD version for that car, but adding the LSD is legal for SP.

The e30 318, although a good car, has a lot of limitations in SP due to the lack of update/backdate. - AB

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'14 Toyota Sequoia Platinum 4WD
Super Westerfield Bros - '93 Integra - LeChump Du Jour
STX 93 - Scion FR-S

Yeah it stinks, alot of the good engine updates VIA UD/BD came when my cars engine was used in the e36. I'm attempting to trade my parts car after I'm done with it for a small case diff at this point. There are a few fitament issues apparently with the medium case diff in my driveline. But I spoke to some folks about the smaller case model and it should be perfectly reliable for me so long as I change the fluid alot.

They are a disc type slip too, so from what I understand about them having a smaller unit should make it easier to tune to my cars lower amount of torque. Hopefully I can find the Smaller case diff in the right ratio. The gearing is another thing that hurts this car. Even If I raise the rev limit 60-63mph is all I'll ever get in second.

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2006 Civic Si - #24 HS for 2015

2005 GMC Sierra
1991 318is Garage Ornament

This must be the only thread on the net regarding BMW rear ends that doesn't mention the Bangle-butt:)
N.
CS-50