Gov Lock Posi... Are they really that bad?

[496truck]

not true on the unlock speed thing.

mine stays locked all the time i am driving if engaged. and takes a stop then backup to unlock most of the time if it dosnt unlock when stoped.

I can't find where I read about the unlocking at speed feature but it was somewhere Volvo related cause they are used in some of the old RWD Volvo cars (I work for a Volvo dealer). Volvo liked the G80 diff for this feature so that it wouldn't be locked while cornering at speed in snow, which they get alot of in Sweden. But I know my K5 will lock from a stand still (both tires spinning in rain/snow) and open up to one wheel after some speed builds, I don't have to stop or reverse to unlock it.

Not trying to argue just going from what I know. Pretty sure there are 2 sets of weights on the G80 locker. One smaller set was to engage the locker when it sensed a differential in wheel speed from L to R. One larger set on the outer part of the diff to disengage the locker at higher overall wheel speed.

 

[Metal Twister]

I can't find where I read about the unlocking at speed feature but it was somewhere Volvo related cause they are used in some of the old RWD Volvo cars (I work for a Volvo dealer). Volvo liked the G80 diff for this feature so that it wouldn't be locked while cornering at speed in snow, which they get alot of in Sweden. But I know my K5 will lock from a stand still (both tires spinning in rain/snow) and open up to one wheel after some speed builds, I don't have to stop or reverse to unlock it.

Not trying to argue just going from what I know. Pretty sure there are 2 sets of weights on the G80 locker. One smaller set was to engage the locker when it sensed a differential in wheel speed from L to R. One larger set on the outer part of the diff to disengage the locker at higher overall wheel speed.

So which Gov lock comes in the 10 bolt, 12 bolt, 14 bolt?

 

[496truck]

Well, I don't really understand what you are asking. They only make one style gov lock, otherwise called G80. You can't see pics here so if you google for pics "G80" or "gov lock" you will see what it looks like. They make this style locker for most, if not all, GM axle types. From what I understand most G80s look the same right up to the 14bolt, which looks different.

These G80s are definitely different in appearance and operation than a clutch type unit, a gear type unit (true track), or a locker like a Detroit or Grizzly or whatever.

I'll link these pics, maybe you can se them...
G80

clutch type

true track

detroit locker

 

[sweetk30]

well to be 100% correct on the gm side of this

g80 option code only = traction adding device installed.

that could be gov loc / posi / detroit.

 

[496truck]

You are correct. I should've pointed that out.

 

[AJMBLAZER]

I had a '92 fullsize Blazer K1500 on 285/75R16's (narrow 33's) and I distinctly remember that with around 85k on the clock the Gov-Bomb/Grenade Lock wouldn't engage while trying to do some easy rock crawling. I had one tire hanging in the air, spinning along happily. The tire on the rock wasn't spinning at all. Almost like an open diff except at first it'd try to turn, then sorta give up, and the hanging tire would just spin and spin.

I knew right there I'd have trouble in the future. It was a 30 spline 8.5" 10 bolt rear axle. By the time I sold it at around 105k a few years later it was pretty much acting like an open diff.

I will say the one in The Blazer's 30 spline 8.5" 10 bolt is working fine although it does occasionally engage with a clunk while coming out of a turn. That's not to say that I trust it at 200k. I have a Detroit sitting on my bench waiting for it.