Posi

[70rs/ss]

A lot of guys implode Gov Locs by getting stuck and or having one tire slip and the other hook, they are not a posi but a slip induced locker (spin one tire, then it engages and BOOM!!) My dad has blown several of those in the snow and ice/getting stuck. A stock posi from a truck 12-bolt is as good as any, but if starting fresh, eaton, auburn, etc are all about the same and $450-500 new.

[shifty]

Originally Posted by Wreckless_71

So basically I've gathered that Gov-Loc=BAD!!! It's just a goofy type of posi then..?

There are pros and cons to every setup. It's not like the gov-lock setup is the worst out there.

I did a lot of reading at off-road forums when I found out that I had a locking diff (the one I linked pics of above), and, basically it ended up being a gov-lock, and quickly realized that more than half the people responding saying bad things had never actually grenaded one themselves, but "knew someone who had" or "knew someone that knew someone who had a brother/sister/cousin/ugly redheaded stepchild who had", or just "saw it somewhere once".

Of the people that had actually grenaded one, the vast majority were putting 600HP+ to the rear end and really pounding the hell out of it, which would probably cause a LOT of stock rear-ends to grenade. Most of the the rest who'd grenaded one were your hardcore guys who are extreme drivers, people who off-road like crazy, go muddin', harsh weather/terrain conditions with brutal driving that didn't really fall into the type of stuff that gov-locks were designed for.

After lots of reading, I walked away with the general idea that:

- Gov-lock rears don't suck, it's the people that expect the gov-lock to act like a badass, super bulletproof, expensive rear-end that suck.

- A hell of a lot of people who say gov-lock rears suck don't have first-hand experience blowing them up, some couldn't even point out a gov-lock in a lineup, so they should probably shut their mouth, rather than share their second-hand opinions.

- Of the people that blew them up, a great majority of the grenading came from severe abuse, conditions and usage which falls outside what gov-lock rears were designed to handle.

- If you are looking for a bulletproof rear-end for hardcore off-roading with large tires and big horsepower, the gov-lock is not for you.

- If you are looking for a bulletproof rear-end for racing with big horsepower, the gov-lock is probably not for you.

- If you're the kind of person who has to sit and do high-RPM stationary burnouts for 10+ seconds every time you reach a stop light, multiple times while driving, or you regularly participate in burnout contests, it's probably not the rear-end for you.

(Some guys are like that with burnouts; I think it's jackassery, and think the occasional burnout is cool, but I'm not going to sit there and smoke my tires several times on the way to the grocery store just to flex my nuts in front of people.)

- If you are looking for a budget posi rear-end for street use 500HP and under, the gov-lock is something you can score relatively cheap, and should hold up to most of what you're going to throw at it.


Now, I'm not saying my second-hand-opinion is any better than the next guy. I'm just consolidating the 2-3 days worth of reading I'd done on gov-lock (the G80 in particular) after finding that I had one in my hands. I haven't beat the hell out of my G80 because it's been on the side of the house for several months. It's never going to see the ~350HP that my LS1 is going to put out.

After reading around, I feel 110% confident that it would hold up to anything I could throw at it on the street with those power specs though (~350HP/350TQ).

YMMV, this is just my 2¢.

[shifty]

By the way - http://67-72chevytrucks.com/vboard/s...d.php?t=300797

[LONGHAIR]

I have only broken one myself....But I worked in a 4x4 shop for more than 10 years, replacing dozens of them in that time.
Most of the time they were in trucks with some engine modification, nothing to crazy though. Most also had larger tires too, 33-35 range.
There were a few that were in 2 wheel drive trucks too.
Boat ramps were pretty good for killing them. Generally it was a spinning and then getting traction issue.

Yes, a person that drives their truck like it is a car, might be fine with one. He might also never know that it is even back there?

The biggest problem is that "usually" when they fail....it is catastrophic!
The little parts (watch mechanism) break and end-up between parts where they cannot fit!
When a "legit" Posi fails, it is really just the clutches wearing out. The "posi" action just isn't what it used to be...or quits totally (like an open differential)
No bomb action.
If you already have one, and don't abuse it, it may be fine for a long time. I wouldn't spend any time or money on installing one though.

[blkboot]

so with a nice beef 383 this unit isnt for me?i mean my motor puts out about 500hp and i do want to tack it to the track,and i will do a couple burn out is it for me??

[GruntyPants]

I did actually have a gov lock come apart in my '94 Z-71. Stock engine and tire size. The only thing I would do is 'occasionally' hit second gear hard around the corner and drift a bit. It finally pooped itself after about 160k miles while running with no load on the freeway. I was able to limp home but had to replace the gears and carrier. Went with an Auburn unit and it took FOREVER to get it broken in so it wouldn't chatter. Might try an Eaton in my '67 when I get to that point.

[blkboot]

do i need this

[GruntyPants]

I think I would stay away from the Gov loc if I were taking it to a track. On a hard launch, or a burnout with 500 HP you run the risk of breaking it when the 'lock' kicks in on the other wheel.

My .02

[Wreckless_71]

so basically you've got one side spinning on wet pavment and when the gov-loc kicks in and tries to grab the other side (lets say on dry pavement with traction) fatal snappage occurs... i see where this could create a bit of an issue.

[special-K]

Think of the Gov-Loc as "stock".If you are modifying or using your vehicle in a way that GM didn`t design the vehicle for then it`s not going to hold up,like most everthing else.Until you modify the whole deal front to back,something will break.Actually,a stock 12-bolt can only take so much.

[70rs/ss]

Spend the money on a good posi and it'll last for 40 years, or find a good used 12 bolt from our trucks and get one with a posi already in it, I have had no fewer than 8-10 posi rears from 67-72 models and most were 4.11 and the rest were 3.73, $3-500 used, or $8-1200 for a shop to built a rear with all new parts, posi etc.