New e34 but needs new Diff
Hi All,
I am the proud owner of a 89 535i 5spd. Its a great car. I had a 87 535i about 2 years ago, but I had to sell because at the time I needed a year round car, and the New England winters made it impossible to drive in snow. The growl of the m30 engine has haunted me ever since, so i gave in, and bought an e34..... =)
The car however will need a new differential. There are so many to choose from, and I'm not knowledgable as to what will fit, and what will not. So my question is, which differentials will fit me e34 5spd? There are people on ebay selling diffs from 325is's and say that they will fit a 535, but just not too sure if that will conflict with the gearing of the tranny. Any help will be much appreciated.
Thank you!
Major Contributor
All E34 differentials are interchangeable. You are better off with a posi-traction LSD if you have a manual. How do you figure that it needs a new differential? Is it whining?
In any case, on www.car-parts.com you will be abel to find many cheap ones - as low as about $100-150
-Artem
3 Grand Master
All E34 differentials are NOT interchangeable.
Some use large housing units, others use mediums. A 535 uses a medium housing.
Furthermore, the flanges are different, beyond the inherent changes between large and medium cased units. All are relatively easy to swap, but incorrectly loading the pinion nut (even the TIS spec is wrong) typically destroys the differential.
I can practically guarantee that I've worked with more differentials than anyone else on .info. Most units from junk yards are just that -- junk. Cars are typically not brought in on a flatbed. Sitting around in muck for years is not good for bearings and gear sets. Most higher mileage limited slip units have weak or bad clutches.
I wouldn't buy a used differential without being able to test drive the car prior to pulling it. There's a reason why we charge a grand and change for a new unit, including a good, long warranty.
best, whit
Major Contributor
Like Whit says, besides gear ratio + LSD or open, you have to make sure you get the correct size diff and the correct input flange type.
I disagree however with the opinion that used BMW diffs are probably junk. Whit may have installed more diffs than me, but I'll wager that I have removed more diffs than him...I have bought and sold many BMW diffs over the years, and only a few that I have sold- maybe 3 or 4, were in anyway "bad"- and 2 of those were suspect to begin with as they came from flood cars and had water in with the gear oil. The rest of them were A-OK. Keep in mind that you would be smart to install new side seals and rear cover gasket for sure, and get a new front (pinion) seal if there is evidence of a leak there, or if you need to have the input flange changed.
You need a diff from any E34 5 series except 540i or M5 to fit your 535i- these will all be the proper case to be a direct bolt-in. You could also use an E32 7 series diff from a 735i/il (but not 740i/il or 750i/il as they use the large case). The front (input) flange for your 5 speed 535i should be the same in any other E34 5 speed, as well as the 7 series cars- they should have the the larger 5 speed input flange, so they would bolt right in. There are exceptions to this, so be careful what you buy, and ask lots of questions. If the seller can't or won't answer your questions, you might want to move on to someone else, or take a risk that you're not getting the right part.
FWIW- car-part.com is notoriously inaccurate in their listings, it's basically a service that junkyards subscribe to to get their inventory listings online. I can tell you from firsthand knowledge that most junkyards do not take the time to check their diffs to make sure of the ratio or if it's LSD or open. They usually just put whatever description they can come up with- regardless of what it says on the diff tag!!
Bret.
Big, Big Time Poster
If you dont mind paying $500 and up, check Metricmechanics or Korman for rebuilt diffs.
Support your American Flag Merchant Marine
No BMW at this time, eyeing a 91 318iS. 00 Saab 9-5, 89 Bronco XLT, 05 Kawi Z1k, 00 Ducati 748S Bip
Big, Big Time Poster
I bought a 3.64 LSD for my last 535 and it seemed to me to be the perfect ratio for that car. (5 speed manual trans) I might be tempted with a 3.73 but anything steeper makes first gear useless. With the 3.64, you get just a hint of overdrive in 5th, I think about a 6-7 percent difference between the 3.46. Mine came out of a 750 and we had to swap the imput shaft. Guessed at the torque but it was working fine while I had it and the new owner has said nothing bad. Maybe we got lucky and got real close on the torque.
Mike Holbrook
Meridian, Idaho
1992 535im, 17", Euro M5 Throwing Stars 8's & 9's, FK-451 235/45s & 255/40s, M5 Sway Bars 25/20, Conforti chip, Lowes Ram Air, glass sunroof
The differential is whining on diff. I had it on the lift, put it 2nd gear then 4 gear, ran it to about 4K rpm and the whine was pretty bad.Originally Posted by ArtemLepilov
I did however ran into some more recent problems. The power steering pump is whining, looks like smaller hose is leaking. Does anyone know if this is common?
Also, the clutch just recently started to become hard to push down. When the car warms up it gets better. When I had the car on the lift the shift shaft seal was leaking.
I brought the car to a mechanic this morning and he says that if it needs a new clutch I have to replace the flywheel also, is this true?
Anyhow, when the clutch gets really hard to put down, is this another common problem?
Any more help would be much appreciated.
Would this fit?
Major Contributor
NO.
Ok, thank you. I was told that a 3.73 e30 LSD will fit in the 535i, is this correct? I believe just the flanges have to be changed.
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