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Is this a gov-lock or posi in my 14sf?

i was referring to puttin a 10b gov-loc in the front not a 14b one :haha: unless of course ur running a 14b up front....only one guy on here can say he is :p:
 
14SF gov-lock I pulled from the diff I bought was broken. I have a feeling that the stronger carrier likely prevents them from breaking in half like the 10 bolt, but the tiny geared teeth that are used aren't going to be much stronger than the 10 bolt design. The teeth were sheared off in mine. Near impossible to replace, according to GM, tech's are supposed to replace the whole carrier, not disassemble to fix individual pieces, although the rebuild kits are still available from GM.

The 14SF carrier I got seems to stay locked up randomly, and these things are NOTHING like a limited slip/posi differential. This will completely stop the 5000lb truck from rolling in a corner if it's locked up. (which it's not supposed to do of course) Limited slip diff's can be tested by how much torque it takes (on a stand) to overcome the spring preload. Those that don't think they work, don't forget that when the *sensed* wheel speed (which would include spinning tires!) over 25MPH means the differential will unlock. So 100RPM+ wheel speed difference locks them, *sensed* 25MPH+ unlocks them.

I don't know the history behind either of these carriers. But the one with stripped teeth, judging by the other rigs in the guys driveway, and the fact that the housing was a newer body style one with '73-91 perches (spacing) welded on, probably led a very hard life, moving a heavy truck and huge tires with a 3.42 ratio, with a heavy heavy foot.
 
That Gov-lock you got looked mint compared to the one it replaced in Stan's truck. The one we chucked was minutes from grenading itself...

I have never been a fan of the way a Gov-lock operates. I had one in an '88 C1500 "short wide" low-rider. Snap the clutch and both tires would spin, then it would disengage.

Rene
 
Yep, the one I got form you guys looked excellent. Believe me, I went over it with a fine toothed comb to make sure the problems with the other one weren't present in it. Somethings going on in there, just not sure what it is. I expect that going around a corner, sooner or later whatever that is stuck, will break. Still got it in the back of my head about what I'll replace it with if it goes. At least with the 14SF I have optimism that "if" is right, not "when". :)

A little interesting going around a corner (with the 10 bolt gov-lock) having one tire spin as you get on the gas, then traction and no spin. Never had the conditions to stay on it hard enough and long enough to reach 25MPH where I could actually tell it unlocked.

Then again, I never got squirelly on slippery curves, and never had the end come around on me either, so I guess it did it's job until it broke.
 
So if it ends up breaking, can I use a lock-rite or something like that, that replaces the spider gears, or do I have to get an open carrier?
 
you'll need an open carrier.

My gov-loc story:

Installed new tranny and per tranny instructions: jack up rear end and let engine run w/ tranny in reverse for 5 minutes, longest five minutes of my life as I listened to that gov loc, lock and unlock!
 
A few more q's.

The 81-87 body style 3/4 ton spring perches are the same as my k5 right?
The axle came out of an 84 or 85.

Also, am I going to need a conversion u joint from the 10 bolt DS to 14sf yoke? Or can I get a different yoke, etc?
 
Twiz said:
The cluch packs are loaded to the case by the side gears. But there is no pre-load, like a "normal" limited-slip. So, it's a (light) limited slip with a goverend locker.
Click to expand...


muhahahahhahaha look whose back!!!!!!!!! :p: :bow: :bow:

Brandy
(sorry to hijack the thread!)
 
Locking Differential Description and Operation
The locking differential consists of the following components:

Differential case - 1 or 2 piece
Locking differential spider - 2 piece case only
Pinion gear shaft - 1 piece case only
Differential pinion gear shaft lock bolt - 1 piece case only
2 clutch discs sets
Locking differential side gear
Thrust block
Locking differential clutch disc guides
Differential side gear shim
Locking differential clutch disc thrust washer
Locking differential governor
Latching bracket
Cam plate assembly
Differential pinion gears
Differential pinion gear thrust washers

The optional locking differential (RPO G80) enhances the traction capability of the rear axle by combining the characteristics of a limited-slip differential and the ability of the axle shafts to "lock" together when uneven traction surfaces exist. The differential accomplishes this in 2 ways. First by having a series of clutch plates at each side of the differential case to limit the amount of slippage between each wheel. Second, by using a mechanical locking mechanism to stop the rotation of the right differential side gear, or the left differential side gear on the 10.5 inch axle, in order to transfer the rotating torque of the wheel without traction to the wheel with traction. Each of these functions occur under different conditions.

Limited-Slip Function
Under normal conditions, when the differential is not locked, a small amount of limited-slip action occurs. The gear separating force developed in the right-hand (left-hand side on 10.5 inch axle) clutch pack is primarily responsible for this.

The operation of how the limited-slip function of the unit works can be explained when the vehicle makes a right-hand turn. Since the left wheel travels farther than the right wheel, it must rotate faster than the ring gear and differential case assembly. This results in the left axle and left side gear rotating faster than the differential case. The faster rotation of the left-side gear causes the pinion gears to rotate on the pinion shaft. This causes the right-side gear to rotate slower than the differential case.

Although the side gear spreading force produced by the pinion gears compresses the clutch packs, primarily the right side, the friction between the tires and the road surface is sufficient to overcome the friction of the clutch packs. This prevents the side gears from being held to the differential case. (except for dyeger535)

Locking Function
Locking action occurs through the use of some special parts:

A governor mechanism with 2 flyweights
A latching bracket
The left side cam plate and cam side gear
When the wheel-to-wheel speed difference is 100 RPM or more, the flyweights of the governor will fling out and one of them will contact an edge of the latching bracket. This happens because the left cam side gear and cam plate are rotating at a speed different, either slower or faster, than that of the ring gear and differential case assembly. The cam plate has teeth on its outer diameter surface in mesh with teeth on the shaft of the governor.

As the side gear rotates at a speed different than that of the differential case, the shaft of the governor rotates with enough speed to force the flyweights outward against spring tension. One of the flyweights catches its edge on the closest edge of the latching bracket, which is stationary in the differential case. This latching process triggers a chain of events.

When the governor latches, it stops rotating. A small friction clutch inside the governor allows rotation, with resistance, of the governor shaft while one flyweight is held to the differential case through the latching bracket. The purpose of the governor's latching action is to slow the rotation of the cam plate as compared to the cam side gear. This will cause the cam plate to move out of its detent position.

The cam plate normally is held in its detent position by a small wave spring and detent humps resting in matching notches of the cam side gear. At this point, the ramps of the cam plate ride up on the ramps of the cam side gear, and the cam plate compresses the left clutch pack with a self-energizing action.

As the left clutch pack is compressed, it pushes the cam plate and cam side gear slightly toward the right side of the differential case. This movement of the cam side gear pushes the thrust block which compresses the right-hand side gear clutch pack.

At this point, the force of the self-energizing clutches and the side gear separating force combine to hold the side gears to the differential case in the locking stage.

The entire locking process occurs in less than 1 second. The process works with either the left or right wheel spinning, due to the design of the governor and cam mechanism. A torque reversal of any kind will unlatch the governor, causing the cam plate to ride back down to its detent position. Cornering or deceleration during a transmission shift will cause a torque reversal of this type. The differential unit returns to its limited-slip function.

The self-energizing process would not occur if it were not for the action of one of the left clutch discs. This energizing disc provides the holding force of the ramping action to occur. It is the only disc which is splined to the cam plate itself. The other splined discs fit on the cam side gear.

If the rotating speed of the ring gear and differential case assembly is high enough, the latching bracket will pivot due to centrifugal force. This will move the flyweights so that no locking is permitted. During vehicle driving, this happens at approximately 32 km/h (20 mph) and continues at faster speeds.

When comparing the effectiveness of the locking differential, in terms of percent-of-grade capability to open and limited-slip units, the locking differential has nearly 3 times the potentialof the limited-slip unit under the same conditions.

Locking Differential Torque-Limiting Disc
The locking differential design was modified in mid-1986 to include a load-limiting feature to reduce the chance of breaking an axle shaft under abusive driving conditions. The number of tangs on the energizing disc in the left-hand clutch pack was reduced allowing these tangs to shear in the event of a high-torque engagement of the differential locking mechanism.

At the time of failure of the load-limiting disc, there will be a loud bang in the rear axle and the differential will operate as a standard differential with some limited-slip action of the clutch packs at low torques.

The service procedure, when the disc tangs shear, involves replacing the left-hand clutch plates and the wave spring. It is also necessary to examine the axle shafts for twisting because at high torques it is possible to not only shear the load-limiting disc, but to also twist the axle shafts.
 
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The 14SF carrier I got seems to stay locked up randomly, and these things are NOTHING like a limited slip/posi differential. This will completely stop the 5000lb truck from rolling in a corner if it's locked up. (which it's not supposed to do of course)
Click to expand...

We used to see something like this fairly often in the mid to late 90s. The clutches would lock up after extened freeway driving. Causeing the vehicle to "hop" around turns. We would pull the bum cover, clean the clutch packs (installed) and work the diff by hand (rotateing the axle shafts). Refill and we used to add a friction modifier - but if I remember correctly, they said not to add the addatives.
 
Cripes!

For a post where the instance of the word 'locking' occurs some 19 times... I still can't see it. :dunno:

There's all kinds of wedging, ramping, and (dis)engaging with cams and whatnot, but it all hinges on the dependability and effectiveness of the clutch pack(s).
 
neverendingproject said:
The 81-87 body style 3/4 ton spring perches are the same as my k5 right?
Click to expand...

yes.

Also, am I going to need a conversion u joint from the 10 bolt DS to 14sf yoke? Or can I get a different yoke, etc?
Click to expand...

Most likely a u-joint. It depends which yoke is on there now. (I don't recommend swapping yokes as it disturbs the crush-sleeve and pre-load on the pinion bearings.)

I will let others make recommendations for the exact conversion joint required.... many people on here are using them.
 
Twiz said:
We used to see something like this fairly often in the mid to late 90s. The clutches would lock up after extened freeway driving. Causeing the vehicle to "hop" around turns. We would pull the bum cover, clean the clutch packs (installed) and work the diff by hand (rotateing the axle shafts). Refill and we used to add a friction modifier - but if I remember correctly, they said not to add the addatives.
Click to expand...

So here's a question: (searched, couldn't find spec) what gear oil did GM say to use with the trucks? I know GL-5 has additive in it for limited slip use, in my case that's what I'm already running. So if GM spec'd GL-5 for, say, a vehicle with G80 (limited slip in a Camaro for instance) do they still say use the additive?

Just curious since the truck service manual states not to use additive, but if GL-5 was already spec'd, perhaps that's why.
 
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