Anyone curious about what a limited slip unit looks like? (56k=no)

[PiercedE30]

Here it is. The tear down of a limited slip unit. I pulled it apart in order to throw an extra clutch in there for more lock-up and to make a 4.10LSD from the 4.10 open that was in my old automatic.
If you intend on trying this, make sure you use a SHORT allen on the allen bolts, otherwise you WILL strip them out. They are 6mm allen bolts. The ring gear is pressed on and you have to get it off with a hammer. It's not all that hard, except getting the speed pickup ring back on, I am still working on that.
Hope this clears some things up and makes it so that the LSD isn't so mysterious to everyone now.

Open rear end:





Now on to the good part:


































































Jon

[Garageaholic]

Oooookay, that's for an S4.10.

can you do the same for an S3.73 please

thank yoU!

[PiercedE30]

Actually, that LS unit came out of a S3.64. I pulled the ring gear out of my old open 4.10 and threw the ring gear on the LS unit for an S4.10. The LS unit is the same between all gear ratios, as long as the diff size is the same (ie, small case, medium case, large case), unless there is a different size for each case size.

[drifty340i]

cheers for that thats very interesting! i need to change my ratio from 3.73 to something around 3.25 for the 8 so i might try find an open 3,25 and use the gear from that to convert it

[ldsbeaker]

that is super cool... doesn't look like it was very worn...

[e30 gangsta]

if i send you a 3.73 pumpkin and the bimmerworld upgraded clutch packs will you do the install for me? :)

[PiercedE30]

Are the bimmerworld clutches replacements, or additions?

[matt]

Are the bimmerworld clutches replacements, or additions?

Where did you get your replacement clutch/disc?

I would hesitate to add clutches without machining the housing and measuring the preload on the stack when you finish... it would be easy to build yourself a 100% lockup diff that way.

If you know somebody with an EDM machine, you can change your ramp angles also...

[PiercedE30]

Yea I know, I'm pulling it back apart next week to measure a few things and polish the spider gears. I wish I knew someone with an EDM machine.
When changing ramp angles, do you change the angle that the side of the spider gear touches? Like the inside walls of the spider gear housing?

[matt]

Yes, you change the angle shown in this picture where the back of the gear is resting.

[PiercedE30]

Yea, I wasn't sure if it was at the back of the gear or somewhere else on the spider gear itself.

[PiercedE30]

Ok, to update this thread. I did get the speed sensor ring on by heating it up and letting it cool and contract around the seat that it is on. It really is very simple.
I don't know why people really think that the rear end is so mysterious. The only thing that I could see as being difficult is setting the pinion depth and preload. Even then, if you have a dial indicator and some shims it wouldn't be very difficult.
I did end up using some scotch brite and a fine brass wire wheel to try and polish the gears. I got them to shine, but not as polished as some of the professional rebuild places can offer.

[TXBDan]

Hey,

What is the drag torque spec when crushing the pinion crush washer?

Thanks!

[OrganicMechanic]

bump--

NEEDS A STICKY!!

[Teaguer]

bump--

NEEDS A STICKY!!

Not exactly something the home mechanic let alone the kids on this board sshould be messing with themselves .


I'll reserve judgement until this car actually drives around with this rebuild .