Looking for a good used Auto Diff.

[osburn383]

I am need of a known good working auto diff 3.64.

Thanks.

[jaredmac11]

Sorry, auto diff would be the diff used for the auto? Or just an open diff?

I may have a contact for the diff off of an auto car, it's in Houston.

[320iAman]

Open Differential is used on manual or automatic transmission models. 320is models had LSD's.
3.91 43:11, 3.64 40:11 Crownwheel/pinion or ring gear to pinion gear ratio.
Randy

[jaredmac11]

Thanks Randy for the reminder.

His would be a LATE open diff. I have a 3.64 open diff in my car, but I havent rebuilt my 3.91 LSD yet so I cant give it up yet, if you can wait. I wish I could make my 3.64 an LSD...

[edu]

I have open non LSD from 1980 323i, that I am considering selling. I asking $350 + freight cost. I am located Los Angeles, CA 90031. LMK if interested. Thanks

[320iAman]

Thanks Randy for the reminder.

His would be a LATE open diff. I have a 3.64 open diff in my car, but I havent rebuilt my 3.91 LSD yet so I cant give it up yet, if you can wait. I wish I could make my 3.64 an LSD...

77-79's 320i's were known for 3.64 open differential and Getrag 242 4 speed transmission-I believe they are exchangable--confirmed at realoem--77-79 can be installed in later models--same part number,bmw 33101209989,due your research and double check. I'm trying to remember if there was an optional 3.64 LSD for these cars,,may have been. Not to rain on someones parade, I bought an open 3.91 differential at pick n pull for $50- 1/2 off day, not that long ago and rebuilt it-new bearings,races and seals, new paint. Its cherry all in oem specifications, plan to install later.

Yes 3.64 did come with LSD 25%,,bmw 33101207337,33101206837,,need to buy the pumpkin--lsd unit--its closed faced,,,

The interchangeability of these cars makes them dynomite..


Somjuan has one-3.64 open differential -I'm looking to get his volume air box with 80 mm sensor plate off his 1979 320i, if not sooner...He wants to get it running with new engine and so forth before he offers up the parts, send him a pm ozzie383..




Randy

[Heretic E21]

My 82 5spd had a 3.64 open diff on it, replaced it with a 3.91 LSD. But I was little confused as I thought all the manual cars that year were 3.94??

[320iAman]

My 82 5spd had a 3.64 open diff on it, replaced it with a 3.91 LSD. But I was little confused as I thought all the manual cars that year were 3.94??

Previous owner may have changed it out from 3.91 to 3.64,,all the 5 sp 80-83 I have seen were 3.91,,that was part of the 80-83 change motor,transmission and differential from 77-79. 2 L to 1.8,Getrag 242 to Getrag 245,240 and differential from 3.64 to 3.91, plus lambda ecu, fmv, cat , and O2 sensor from egr system, adjustable Fuel Distributor from non adjustable Fuel Distributor....

Randy

[osburn383]

Previous owner may have changed it out from 3.91 to 3.64,,all the 5 sp 80-83 I have seen were 3.91,,that was part of the 80-83 change motor,transmission and differential from 77-79. 2 L to 1.8,Getrag 242 to Getrag 245,240 and differential from 3.64 to 3.91, plus lambda ecu, fmv, cat , and O2 sensor from egr system, adjustable Fuel Distributor from non adjustable Fuel Distributor....

Randy

Thanks for the responses guys.
I found found one from a salvage yard for $168 shipped to me with supposedly 75k on it.
Hopefully this one works out.
If not i will keep those who responded in mind.

[320iAman]

Good, glad to hear you found one.. 75K sounds really good.

Randy

[okieflats]

BMW E10 2002 E21 320i 3:64 DIFFERENTIAL - $375 (petaluma)

STANDARD SIDE LOADER DIFFERENTIAL 3:64 RATIO.
GOOD CONDITION / WILL SHIP.
$375 / OFFER.


CALL JEFF AT SUTTON ENGINEERING 707-762-5517




https://sfbay.craigslist.org/nby/pts...554927910.html

This guy is asking more than what a whole parts car is worth.

(Glad you found one, btw)

I always search CL for "BMW e21" and see what pops up.

[osburn383]

Well hell......
So I go the used diff installed and it makes the same front pinon bearing whir noise as the other used diff.
To make sure it wasn't my driveshaft i reinstalled my original diff and no noise.
Just the whine at higher speeds.

Just going to listen to a whine for a while until i want to try this again.
Not sure if i want to play the lottery on any more used parts though.

[320iAman]

What kind of noise ? No noise at low speeds--then noise from the rear end at 40 mph on up ? That could be rear axle bearing..

Randy

[osburn383]

What kind of noise ? No noise at low speeds--then noise from the rear end at 40 mph on up ? That could be rear axle bearing..

Randy

I had the car on jack stands and put in drive.
Could easily identify the noise was coming from right at the front of the diff.

What spurred me to put the old diff in was that i could spin the output stubs and hear the noise on the first used diff and not from my original diff.
Crazy that two diffs had the same problem.
Both had now whine at speed just he whirr sound.

[320iAman]

From Haines:
A noisy differential unit will necessitate its removal and overhaul or it exchange for a reconditioned unit. Before taking this action,check the following components as its possible for sounds to travel and mislead the owner as to the source of the trouble.
Check for:
Loose driveshaft flange
Tyres out of balance
dry or worn rear hub bearings
worn final drive mountings
damaged or worn driveshaft CV joint
worn or seized driveshaft ball grooves
Loose road wheels


Two differentials making the same noise,, possible but.....

Randy

[okieflats]

I suppose the late model '81-'83 with automatic transmission had a 3.64, while the 5-speed manual with overdrive had a 3.91. That would be because the automatic is not overdrive. And the early models '77-'79 didn't have overdrive either so they did not come with the 3.91.

[320iAman]

Yes-automatics 80-83 did come with 3.64-originally,-pushing 5 speed trans with 3.91--,, and 320/320A came with 3.9 to 1 ,,39:10 ratio and 3.91,, 43:11 ratio and it had no over drive mentioned.

As too the noise- whistling noise-Add to Check for--faulty centre bearing,,possibly vibration down the drive line ending at the differential--nose section...

So long as the Differentials are the same size, same configuration any gear ratio will work, mods are possible.

Randy

[82Kashmir]

The noise level (whine and hum) that is typical in the 82 320i automatic with a 3.64 Dif, my DD is something I've been chasing also. Going to take a video with sound at 55-70 and post it to see if it is normal. If these cars have a certain amount of noise I'm looking for acceptable level, advice welcome. Recent discovery my exhaust hangers were bad replaced and buzz is lower, however their is still a whine. I know there is a lot to check still.