Pulling hard to the right in 4wd

[496 BB]

Anyone have this happen? Ive noticed it before but not as bad. This is on snow covered streets and I noticed it yesterday only when I give er a bump on the gas pedal. Suggestions or normal? Thanks.

 

[trouttrooper]

Not normal. I can let go of the steering wheel in 4wd, hit the gas, and still go in a straight line.

When you say bump are you spinning tires or just accelerating?

Something binding up in the front differential???

 

[496 BB]

No binding. Its more like from a stop I get in it a little and it does it. They might be spinning but doubt it. Cant really tell. It just feels like its grabbing real hard and pulling right. Kinda like a street car at the strips and launches and the rear right side squats real hard or the left but usually right.

Does sleeves help this?

 

[stacks04]

doubt sleeves helps it, but it may have something to do with your steering linkage. check for play in everything, with the front end jacked up.

 

[MACKIN]

I think your spinning and it's just pulling to the side that is driving. Mine does the same thing when I jump on the go peddle. Most 4x4's do it.

Sleeves are put in to support the weak tie rods they have been none to bend under stress.

 

[btfarm]

Your front hubs ok? Any grinding noises? Could be your rear locker puked. Tire pressures all equal? Just a few things to think about...
Once above about 30 mph the Eaton will unlock and could be giving you some twist.

 

[496 BB]

Man that stock locker is a piece. Hate it. Its like my ole lady it only works when it feels like it.

Hubs I think are starting to go as I just recently noticed the "super swamper" sound on em as with the 3 sets Ive already put in wifes Jimmy. Just early stages so its not those I wouldnt think

Im thinking Mackin's right as it just is more noticeable without the TM on there. I will check all fittings also to see everythings ok. Thanks.

Also why does the rear automatically lock when in 4wd? Always feels like its binding somewhere but have checked and its the rearend locked.

 

[BudTX]

That rear axle automatically locks at speeds under 30 mph whether in 4x4 or 4x2.

 

[trouttrooper]

Also why does the rear automatically lock when in 4wd? Always feels like its binding somewhere but have checked and its the rearend locked.

You sure it's not just the binding between front and rear?

One tire has to spin a little before the G80 will kick in. No relation to weather it's in 4wd or not.

 

[496 BB]

That rear axle automatically locks at speeds under 30 mph whether in 4x4 or 4x2.

Not mine. Sometimes its a one wheel wonder :mad2:

 

[btfarm]

Not mine. Sometimes its a one wheel wonder :mad2:

Doesn't take much in a burnout or on snow to get the rear wheels spinning fast enough to get to 30 and unlock.

 

[496 BB]

Thats true...never thought bout it that way. Damn GM with all its no fun parts

 

[stacks04]

here is the gm description of the rear gear set in the trucks.



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.
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 potential of 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.

 

[MACKIN]

I believe there is a bit of misconception here on how the E-locker works. I believe the correct terminology is it will NOT lock above approx 20 MPH.

I don't know about you guys but I've seen my dually spin LOCKED above 70 mph starting from zero MPH.

It is a wording issue.

So here is this particular case is. He jabs the throttle from a dead stop the Eaton makes one revolution and locks both wheels in the rear. In 4x4 and a open differential power is applied to one wheel in the front and in this case the right. It grabs traction and pulls to the power side.

NOW if he was rolling along on wet dicey rodes at 20 mph and jabs the throttle in theory the Eaton locker should NOT lock at this point.

 

[Max Attitude]

Sleeves won't help, I have sleeves and have the same issue. I think it's even more noticeable with the dmax. Can't remember how bad my old truck was but not this bad. The torsions turned up doesn't help...mine are all the way up. I only cranked them that high because the cv angles aren't bad at all. :shrug:

I know my idler/pitman arms aren't in the best shape so I'm sure that don't help any.