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lsd problem

mad-butcher - 3/8/05 at 05:38 PM

hi guys
i aquired a 3.6 lsd with what i was told was a worn bearing, a lot of movement in the output shaft so i decided to change the bearing. having done that i still have the same problem, on closer inspection the play appears to be in the gear pointed to in the photo . are these gears mounted in bearings or is the dif F####d
many thanks
tony
Rescued attachment P8030002.jpg

mark chandler - 3/8/05 at 07:39 PM

These are the planet gears, if you pull the halfshafts out and the middle pin they will then drop out.

These things are shimmed so you should be able to bring them more into mesh, however I do not know if you can get the shims to repack, you may be able to make something out of shim steel.

Measure the gap with feeler gauges before you dissassemble, ie behind the gear on the housing and mike up whats in there.

Cheers Mark

mookaloid - 3/8/05 at 09:56 PM

quote:
Originally posted by Dave Ashurst
Tony, Did you mean lsd? I've never seen a sierra one but that doesn't look very LSD to me. If it is, how does the limited slip action work?
regards
Dave

The sierra LSD is not a true LSD - it's a viscous coupling which grips as the fluid between some plates heats up with some wheelspin. It is housed on the back of the crown wheel which is why it looks like a normal diff.

Cheers

Mark

Wadders - 3/8/05 at 10:28 PM

This is hard to describe but when you say loads of play, do you mean like end float, ie the output shaft moves in and out? If so this is normal for a sierra LSD, usually on the crown wheel output shaft, mine moves laterally about 5mm and with the cover off the planet gears don't appear to mesh fully, but in practice it makes no difference.
Not blown mine up yet anyhow, and its had serious abuse.

madman280 - 3/8/05 at 10:42 PM

Firstly to answer your question. No..that spider gear does not have a bearing. It has a thrust washer if it is an open diff...or will have the clutches between it and the diff carrier if it's a clutch type LSD. Now, as to it being a viscous LSD..doesn't look to be one, but I'm not familiar with the seirra. I would wager it being a clutch type diff . If you turn one output axle against the other in opposite directions is there resistance? (right side forward left side in reverse)
Now as to that being the problem--quite unlikely..as that gear only turns if there is a difference in speed from one rear wheel to the other...the axles attach there don't they?...
I'd be more inclined to suspect a bad pinion bearing. If you don't know how the thing works you might want to get some qualified help fixing it properly as it requires special knowledge and tools.