Rebuild Gov-lok or spring for Eaton?

[SUX2BU99]

I'm thinking on passing on the 700R4 upgrade from my TH350 and go instead for a diff rebuild. The factory Gov-lok isn't working and I can either purchase a new one (which apparently are built by Eaton) for about 1/2 the price of an Eaton limited slip unit. I know the aftermarket Eaton will be much stronger and last longer than the OEM style unit but I'm not sure how 'bad' the OEM unit would be. I wouldn't abuse either unit by doing right-hand turn WOT burnouts, but I might try to do that odd left-hander tail-swinger here and there   Biggest concern if having both tires to put the power down when racing. My truck isn't a dragstrip warrior but the 1-tire fire is affecting my launch.

So, for what I want to do and need it for, is springing for the Eaton worth it?

And, is an entire diff rebuild a necessity or just a good idea to do? I'm also contemplating going up to 3.73's while the work is being done, up from the 3.40 I have nw.

[VileZambonie]

Do it righ the first time. Gov-loc = broken.

[Hertzdaddy]

I haven't heard anyone that likes a gov-loc, especially if you will drag race. Many tales of exploding diffs. Go with the Eaton posi. Its stronger and rebuildable too. And its a better unit for the street than a locker.

Eric

[VileZambonie]

If you're lookin for smooth and powerful check out auburn pro-series carriers. The only downside is they're not rebuildable but I haven't broken one yet.

[SUX2BU99]

Seems like the smart thing to do is to not spend the money on a rebuilt Gov-lok. I'm surprised that you recommend the Auburn, Vile. Seems most of the responses I've seen when googling this topic is that Eaton's are always recommended whereas Auburn's are about 50/50. I thought the Auburn cone clutch design was interesting until I read about them not being serviceable once the cases are worn out. Friend of mine put one in his 83 Z28 when he blew up the stocker and it worked great but this was 15+ years ago.

[SUX2BU99]

And, is an entire diff rebuild a necessity or just a good idea to do?

Anybody have comments about this? Must I spend more on a new bearing kit and such?

[VileZambonie]

I have an auburn pro behind a pretty powerful big block and have never had a problem with it. Sure you can rebuild a clutch pack which would be more suitable for drag racing but for a mostly street driven truck they're smoother and they bite hard.

I would at least get new carrier bearings and a shim kit.

[SUX2BU99]

Thanks for the input. I have found that a local rearend specialty shop is selling a pre-Gov-Lok, but OEM-style rebuilt Eaton.  I asked how it could be OEM-style but not a Gov-lok and they said this was the kind of LSD that GM used before Gov-lok came out in 1973. The picture looks just like a newer Eaton Posi, but you can tell it's an older case. It does not look like the typical Gov-lok. I've asked if this is as good as a newer Eaton since they look like the same design, or more of an in-between the Gov-lok and the newer Posi.

[Captkaos]

The one they used before the Gov-Loc was the one currently label Eaton Posi.  Same design, just uses carbon clutches now.  I have one in the truck I am building.  If I was to buy another one, it would be the Eaton Posi.

[SUX2BU99]

Great to know, it'll be worth trying to purchase then. I'll ask if they upgraded the clutches at all. Makes a person wonder why they bothered at all with the Gov-lok design. It is intriguing though to look at it and wonder how it all works. Must have been smoother operation or something, or cheaper to build.

[VileZambonie]

The idea behind the gov loc is that it's only used when needed otherwise acts like an open differential.

[SUX2BU99]

I was reading a little bit of history about the Gov-lok and the design is intriguing but it's application falls short when it comes to strength and reliability.

Anyway, if I can snag this older rebuilt Posi I will, otherwise I found a new one for a great price too. I've found a couple Auburns for around the same price. Personally, I'm not a huge fan of clutches since they wear out and rely on how well they hold to determine how well they work. I like the Auburn design since there are no clutches, but it too relies on friction (the cone gear pressing against the case) and that too can wear out. Probably it will just end up coming down to price and availability on which one I get.

[Captkaos]

The Gov-Locs work as designed in the applications they were designed for.  They were NOT designed for drag racing, and have recieved a bad rep from this.

[team39763]

LOL...I'm still pushing my luck running the Gov-lock.  I don't know how or why it's still working, but it is.  I plan to buy one of those Yukon LSD's.  I read that they are almost a complete copy of the Eaton unit but for a lot less cash.  I also read that Eaton is in the process of sueing them for copying their design.  You may want to give them a look.

[SUX2BU99]

I ran across a few people saying that, about the Yukon. I'll have to take a look at that. Their ring and pinion sets are quality pieces so I don't doubt their LSD is built well too.