For a little while now, whenever I'd take off, my rear would clunk. I jacked it up in the air today, and found out the clunk is from some play in the differential. You spin one tire, and you have to move it a little bit before the other one moves too. Same with the driveshaft, you twist it and it takes just a little bit for the wheels to kick in.

Its an LSD rear end (GSL-SE), mabey the clutch is going out? Diff is dieing? I dont know much on differentials here, so any suggestions would be greatly appreciated.

 

Definitely not the clutch, since the clutch is located between the engine and the transmission.
I have exactly the same problem with my LSD '85 GSL--- if I launch with anything less than extreme care I get the clunk, and the last time I had the back end on jack stands I found play between the drive shaft and the axles. Definitely a problem with the diff.
Since this is the first time I've had this problem with any of the four 1st gens I've owned I don't yet know the exact repair required or how long it will hold out in its present condition before it breaks.
Anybody else?

 

How many miles on these cars? Sounds like ring/pinion backlash is too loose. Not really a backyard fix. Unless you have a good dial indicator to measure/adjust it. Make sure it isint your driveshaft u joints.

 

Backlash is set by those spacers that they sell, right? They sell em in fraction of a millimeter thicknesses...

I've heard you can use paint to check the backlash. You put some paint on the pinion and put the diff together, then you spin it and see how much paint gets on the ring... Or something like that... I dunno... It mighta been some redneck thing because this dude was doing that to his Camaro. (And no, I'm not saying all Camaro drivers are rednecks... This kid was a ginuwine (sic) redneck.)

EDIT: I'm actually gonna suggest that you doublecheck... Hold differential input flange and turn the driveshaft... Check your u-joints in the driveshaft... Every diff I've seen had had a little play between the two drivewheels... No sense in pulling apart the diff if you don't have to.

 

Aviator 902S, he's talking about the clutches in the LSD. The LSD in out 7's is a clutch type. Basically, it works kind of like a normal clutch from the engine. It keeps things locked up untill a certain torque is reached when the clutch begins to slip.

 

I was talking about the LSD clutch. EDIT: beat me to it 85rotary power!

My car has a little over 100K on it, but I have no idea how much that rear end has on it. I got it from a junkyard, physically it looks like its in really good shape.

Its not gonna be the drive shaft u-joints, the shaft is brand new from mazdatrix. Has about 4K on it.

So carl, how many hours of labor does this usually take to fix? More importantly, how long can I let it be like this? I'm broke right now, so it might have to stay that way for a while.

 

i had the same thing first it was u joints ,it still did it now I think I have an axle seal gone

 

double post

 

damn submit button

 

Thanks for the clarification. Now I'm wondering if this is a worthwhile fix or would it be cheaper to just install a rebuilt diff.

At some point I may just swap in a GSL-SE suspension so I'd like to avoid a rebuild if at all possible.