Locking Differentials

[Z71_Texan]

My old Z71 had a locking differential that required frequent fluid changes and also an additive.

My 2005 Z71 owners manual does not mention frequent fluid changes or the additive.

Has Chevy improved them so now none of that is required?

[norwood]

The current optional locker is the same as it's been for a number of years. They're made by Eaton. No additive needed that I know of. Your old Z71, how old? Possibly an after-market locker of another make?

[White Lightening]

Originally Posted by Z71_Texan

My old Z71 had a locking differential that required frequent fluid changes and also an additive.

My 2005 Z71 owners manual does not mention frequent fluid changes or the additive.

Has Chevy improved them so now none of that is required?

Z71, can you define if you have the locking differential - or the limited slip differential? They are different. Mine (not a Z71) has the locking differential in my 2004 - and frequent changes are not required.

[spudglo08]

All Z71's come standard with lockers.GM doesnt offer limited slip diffs in trucks only automatic locking diffs or open diffs as far as i know.

[spudglo08]

All they need now a days is a bottle of 90W or a bottle of GM's overpriced synthetic purple shit every 100K or so unless you offroad alot then about every 80K or so should do.

[twomorestrokes]

Originally Posted by spudglo08

All Z71's come standard with lockers.GM doesnt offer limited slip diffs in trucks only automatic locking diffs or open diffs as far as i know.

The optional Eaton G80 locker is different than the regular limited slip that is also available on these trucks.

I don't see a fluid change interval in my owner's manual, just periodic checks. However, mine is due for a fluid change because it's starting to chatter when hot. Eaton says NOT to use limited slip additive in their differentials, as it leaves a residue on the steel discs that can make it worse. It uses 75w90 synthetic I believe.

[Z71_Texan]

Originally Posted by norwood

The current optional locker is the same as it's been for a number of years. They're made by Eaton. No additive needed that I know of. Your old Z71, how old? Possibly an after-market locker of another make?

My old Z71 was a 2000 and they DID require frequent fluid changes and the additive. GM had a lot trouble with them and did much warrenty repair/replacement. It sounds like they solved the problems.

Thanks for the info folks!