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factory locker question...

noJeepshere

noJeepshere

I Drove Trains!
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my 99 yukon came from the factory with the g80 locker, thats what the code in the glovebox tells me. well today, just goofing around i put one wheel on bare pavement and the other on snow and kinda power braked it. and nothing. the wheel in the snow just spun and nothing happened. my dads 99 sub has the g80 also, and it grabs in a spin situation and wont let go for a while, usually until i get going. whats the deal? if its a locker it shouldnt wear out should it? or is this a limited slip piece of junk? i want to get rid of it anyways but thought id field the question. maybe its the fact that my grandpa used it hunting some on his property, but that shouldnt wear it out that bad, its also been in snowy country all its life while the sub came from california. and there was no thread i found to answer this question.
 
I'm assuming it's still the gov-lock. Power braking won't work, it needs different axle speeds to work, power braking (if the brakes are right) probably limits wheel spin.

Don't use the brakes, slowly apply gas on slippery surface. It will unlock somewhere around 25MPH, but under that it should stay locked up. Easier to tell if it's locked up on a slight sidehill. If the rear end slides downhill, it's locked.
 
i lightly powerbraked just enough to hold me there and let the wheel spin on the ice. i went all the way to 30 mph sitting still with one wheel spinning and the other not. as far as the locker in question, no doubt its the factory gov-lok, as my grandpa had it, then my brother, now me. niether of them did anything to the axle, and they both drove it nice. i read that they dont work for a while, then act like spools then break. what will that do to the rest of the diff? should i do preventive maintenance, or will it be safe to let it go, then change it? i r a poor college kid.
 
Be easy on it (no intentional burnouts, standard tire sizes) and it should be fine. There is no preventive maintenance on these things. Drive it until it explodes, replace rear axle assembly
 
dyeager535 said:
I'm assuming it's still the gov-lock. Power braking won't work, it needs different axle speeds to work, power braking (if the brakes are right) probably limits wheel spin.

Don't use the brakes, slowly apply gas on slippery surface. It will unlock somewhere around 25MPH, but under that it should stay locked up. Easier to tell if it's locked up on a slight sidehill. If the rear end slides downhill, it's locked.
Click to expand...

It will stay locked above 25mph once locked, it just will not lock above those speeds. Once it is locked it stays locked until the power is removed. Sometimes they take a few tries to get them to lock.
 
Few points about the factory gov-loks, I've played with a number of them.

--They won't grab until the diff is good and warm. You said you put one wheel in snow, so it's not warm out where you are--it'll probably take some driving to get the oil warm.

--Specifically, the unit is a clutch activated locker. If the clutches are worn out, it just won't grab, but once it grabs it's locked. Properly calibrated the unit requires a difference of 100RPM's between the two wheels to activate. So if the slow wheel (better traction) is turning @ 200RPM's the other will have to spin up to 300RPM's for the locker to activate.

--Because it does have clutches it requires limited slip lube in the diff oil to work properly. If the oil's been changed/topped up a few times, it may not have LS lube in it.

--As was mentioned, they will stay locked as long as power is applied, but will not activate above 25MPH. With stock tires in low traction situations, they're a great unit, but they are not designed for brakestands/powered launches on dry pavement.

Just a few points to help with diagnosis ;)
 
Usually the entire thing. At least on the older trucks, it's a lot cheaper than redoing the guts. Or just getting a larger rear axle.

They usually take everything out when they go, up to and including the diff housing.
 
You really need to pull the cover off and have a look inside and change the oil.. Dont drive it till it blows.
If it is not locking up The fly weight that controls lock up may be broken off or the shaft it rides on may be bent and the fine toothed gear that controls lock up may have some stripped teeth. What happens if things are bent or broken eventually is the fly weight falls off floats around the diff, gets weged between the ring and pinnion or spyder gears. That will cause it to go BOOM.. Then you have to buy a new rear end.
You really need to pull the cover and check it out ASAP.
It is also a possibility the clutches are worn keeping it from locking up.
Check things out. If all looks well mabe an oil change will get it working again. Use regular good quality gear lube to refill.
Synthetic gear oil can make the seals leak in older axles not designed for syn oils.

--Because it does have clutches it requires limited slip lube in the diff oil to work properly. If the oil's been changed/topped up a few times, it may not have LS lube in it.
Click to expand...

Both GM and Eaton say additive is not needed in a Gov-Lock.
Both say GL-5 gear lube.
 
Thunder said:
You really need to pull the cover off and have a look inside and change the oil.. Dont drive it till it blows.
If it is not locking up The fly weight that controls lock up may be broken off or the shaft it rides on may be bent and the fine toothed gear that controls lock up may have some stripped teeth. What happens if things are bent or broken eventually is the fly weight falls off floats around the diff, gets weged between the ring and pinnion or spyder gears. That will cause it to go BOOM.. Then you have to buy a new rear end.
You really need to pull the cover and check it out ASAP.
It is also a possibility the clutches are worn keeping it from locking up.
Check things out. If all looks well mabe an oil change will get it working again. Use regular good quality gear lube to refill.
Synthetic gear oil can make the seals leak in older axles not designed for syn oils.



Both GM and Eaton say additive is not needed in a Gov-Lock.
Both say GL-5 gear lube.
Click to expand...

word to that. i dont want to or have the money to buy a new rear end. any way i can remove the gov-lok portion of the diff until i can get a detroit or something like it? im looking at either a lock-right or a true-trac. cant afford anything more. this rig is mostly street driven with some offroad use, i would like a detroit in the back, but cant afford that right now. i drive real nice and have smallish tires, so blowing anything up fully locked prolly wont happen. anyplace to get a good used one? thanks for all your help guys.
 
Last edited:
The gov-lock is a complete unit. You have to remove the whole carrier and replace it with something else like an open carrier, Detroit, ECT.
if you want a lock rite. It wont fit in a Gov lock carrier. You need an open carrier to install a lockrite or other lunch box locker.
E-bay is the best place I know to get a cheap locker. I have bought a few there for a great price. Just have to keep watching the auctions. You can get Gov bombs on ebay real cheap also.
 
Thunder said:
You can get Gov bombs on ebay real cheap also.
Click to expand...
replace a gov-bomb with a gov-bomb? ok.:wink1:























so the detroit locker it is! if im going to put down that kind of moolah for a differential, its going to be good, no limited slip!
 
Wrench said:
Few points about the factory gov-loks, I've played with a number of them.

--They won't grab until the diff is good and warm. You said you put one wheel in snow, so it's not warm out where you are--it'll probably take some driving to get the oil warm.

--Specifically, the unit is a clutch activated locker. If the clutches are worn out, it just won't grab, but once it grabs it's locked. Properly calibrated the unit requires a difference of 100RPM's between the two wheels to activate. So if the slow wheel (better traction) is turning @ 200RPM's the other will have to spin up to 300RPM's for the locker to activate.

--Because it does have clutches it requires limited slip lube in the diff oil to work properly. If the oil's been changed/topped up a few times, it may not have LS lube in it.

--As was mentioned, they will stay locked as long as power is applied, but will not activate above 25MPH. With stock tires in low traction situations, they're a great unit, but they are not designed for brakestands/powered launches on dry pavement.

Just a few points to help with diagnosis ;)
Click to expand...

Thats great tech there!
Is the 14ff gov loc the same? as in needing LS lube? This may explain my hit and miss locker performance... I know it used to work great, but I mud a lot so I change the lube frequently and haven't added the LS lube. A buddy told me that it wasn't necessary.
 
thanks for all the help guys, much appreciate it! just to let yall know, ive set up a locker fund to put a little i can afford into it every month until i can buy a detroit. once again, thanks.:waytogo:
 
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