Which Lockers?

[steiny93]

So I have the 03 2500hd with the locking rear diff which doesn't work well for how this truck is used. I'm typically out of the speed range of the rear diff when I need it.

 

In the rear:

What is the prefered limited slip option for the 2500hd's? I just got off the phone with a dealer for www.arbusa.com and he is pulling together some eaton elocker options. (I guess there is a limited slip elocker that you can take to full lock via the switch/magnet)

 

 

For the front:

The current front end is 'ok' but when it gets rough it quickly goes to a one wheel wonder in the front. Having a locker in the front would be a huge plus. Is the elocker the way to go in the front as well?

[steiny93]

from the lack of response I'm guessing that adding lockers isn't very common on this board

if anyone has any experience's with lockers please chime in

 

i did get the info back from arb....

elockers only available for the front on my vintage of 2500hd, be about $600 for just the front

 

arb's available front and rear;

basically $2000 for all that is needed including the compressor

 

the downside being that both of these setups are open when not locked, which is just as evil as I have now in the rear, my initial understanding around the elockers was that they were limited slip when disengaged but that isn't the case and they aren't available in the rear regardless

 

bummer

[98silvz71]

from the lack of response I'm guessing that adding lockers isn't very common on this board

if anyone has any experience's with lockers please chime in

 

i did get the info back from arb....

elockers only available for the front on my vintage of 2500hd, be about $600 for just the front

 

arb's available front and rear;

basically $2000 for all that is needed including the compressor

 

the downside being that both of these setups are open when not locked, which is just as evil as I have now in the rear, my initial understanding around the elockers was that they were limited slip when disengaged but that isn't the case and they aren't available in the rear regardless

 

bummer

 

I looked into that route for my 98 1/2 ton when I tore the locker all to hell. Basically it was too expensive and not worth my time. Unless you are offroading with it and/or mudding with it. That is the only time you need a selectable locker. I still drive in the muddy fields for wood and etc and my stock G80 locker does just fine. Even when I drive fast.

[brims]

It seemed for a while a lot of guys were talking about putting in Detroit lockers. Pretty sure those are locked until you don't need it to be like in a turn. Not sure if that's any help as you want it to be limited slip. Though aren't limited slips for cars and lockers are for trucks? I don't know if that's a hard rule or just a rule of thumb.

 

I also thought there were lockers, open diffs, and limited slip diffs, I didn't know there was a crossover between LSD and locker.

[ATMINF]

The lockers in the 14bolt trucks are actually pretty strong and last, so most guys don't mess with them. The 10bolt g80 do have a rep for breaking, but there is some debate on the cause. For example guys running large tires and doing alot of off-roading and then wondering why the g80 went out. But overall what I have seen is that people don't understand how they work, and then have a misunderstanding that the rear end suck. Many people don't understand that the g80s are made to only stay engaged at a lower speed, and that when it engages you have to stay on the gas. Many times I have talked to guys that did not know that when the speeds are higher(even when you are not moving but the tire is spinning) the g80 won't lock, because if it did the thing would explode. And also when it does lock you have to keep a steady speed below 20-25mph and then let it pull you out then as you get out or speed up and move along it unlocks. But overall I have not heard of too many 14bolt G80 breaking though.

[chakis24]

It seemed for a while a lot of guys were talking about putting in Detroit lockers. Pretty sure those are locked until you don't need it to be like in a turn. Not sure if that's any help as you want it to be limited slip. Though aren't limited slips for cars and lockers are for trucks? I don't know if that's a hard rule or just a rule of thumb.

 

I also thought there were lockers, open diffs, and limited slip diffs, I didn't know there was a crossover between LSD and locker.

 

the g80 is actually a limited slip when it isnt engaged. ford has a limited slip for its trucks too im pretty sure.

[hockeypro1411]

It seemed for a while a lot of guys were talking about putting in Detroit lockers. Pretty sure those are locked until you don't need it to be like in a turn. Not sure if that's any help as you want it to be limited slip. Though aren't limited slips for cars and lockers are for trucks? I don't know if that's a hard rule or just a rule of thumb.

 

I also thought there were lockers, open diffs, and limited slip diffs, I didn't know there was a crossover between LSD and locker.

 

the g80 is actually a limited slip when it isnt engaged. ford has a limited slip for its trucks too im pretty sure.

 

 

Actually the G80 works as an open differential when not engaged.

[ybsane]

from the lack of response I'm guessing that adding lockers isn't very common on this board

if anyone has any experience's with lockers please chime in

 

i did get the info back from arb....

elockers only available for the front on my vintage of 2500hd, be about $600 for just the front

 

arb's available front and rear;

basically $2000 for all that is needed including the compressor

 

the downside being that both of these setups are open when not locked, which is just as evil as I have now in the rear, my initial understanding around the elockers was that they were limited slip when disengaged but that isn't the case and they aren't available in the rear regardless

 

bummer

 

The ARB air lockers work very well if you are the type of person who does 50/50 highway-off road driving. For everyday driving an open diff works fine, when you go off road you will have an advantage to lock the rear only and if it gets more intense lock the front diff also.

 

I had a CJ-8 Scrambler with this set-up and it worked great, I could drive to the trails with open diffs and as soon as I hit the trails I could air down the tires and lock the rear, unless I hit some deep mud and or steep rocks the front locker was not needed.

 

You could save some money and get a detroit locker for you rear and a ARB for the front. If you tell us what you intend to drive in when off road and how much street driving is involved we can help you out more.

 

Rob

[steiny93]

thanks for the replies,

 

I understand how the g80 works and the issue is that it's an open diff at speed. This is a major problem as I tow lots and during the winter I'm constantly slipping 1 of the rear wheels on ice. This issue gets much worse when we are offroad, typcially we are offroad on ice (frozen lakes) with lots of snow pack.

 

For me going to a limited slip with the option to lock in the rear would be best. (my current understanding is that this isn't an option)

With that as an option I think my best solution would be to get a limited slip in the rear.

 

in the front I'm thinking a locker of some flavor, but this is definately a secondary concern

 

 

personally, I'm baffled that gmc doesn't have a limited slip in the 3/4 tons, we've already lost the 'auto' feature, why take away limited slip as well

[chakis24]

Actually the G80 works as an open differential when not engaged.

 

i thought it was a limited slip until it becomes fully locked. pretty sure i read that on here somewhere.

[steiny93]

Actually the G80 works as an open differential when not engaged.

 

i thought it was a limited slip until it becomes fully locked. pretty sure i read that on here somewhere.

 

 

you may have read that it was limited slip that that is incorrect, it's open

[Diesail]

I am not sure what axles you have but from your described use I would be looking at the ARB air lockers or the Eaton ELockers if I where you. The downside to either of these that they require user input to lock. Meaning you have to push a button. Both of these units are completely open until you push the button then they are a full locker. If ice wasn't one of your requirements I might suggest the Detroit Truetrac, but the Truetrac requires SOME traction at both wheels to work and they might not be the case on the ice. I rean ARBs front and rear on a jeep for years and they were bulletproof. The one advantage that the ELocker has over them is that it does not require an air source.

 

And for what it is worth, the G80 is only a GM option code for a GM limited slip. They come in many many flavors depending on the vehicle and axle. Some are limited slip units with clutches others like the AAM 11.5 unit are a type of demand locker that senses the difference in wheel speed and locks completely.

[dlstewart01]

I am not sure what axles you have but from your described use I would be looking at the ARB air lockers or the Eaton ELockers if I where you. The downside to either of these that they require user input to lock. Meaning you have to push a button. Both of these units are completely open until you push the button then they are a full locker. If ice wasn't one of your requirements I might suggest the Detroit Truetrac, but the Truetrac requires SOME traction at both wheels to work and they might not be the case on the ice. I rean ARBs front and rear on a jeep for years and they were bulletproof. The one advantage that the ELocker has over them is that it does not require an air source.

 

And for what it is worth, the G80 is only a GM option code for a GM limited slip. They come in many many flavors depending on the vehicle and axle. Some are limited slip units with clutches others like the AAM 11.5 unit are a type of demand locker that senses the difference in wheel speed and locks completely.

 

See video..

 

http://www.youtube.com/watch?v=-sw9DwurQAs

 

What GM says about the G80 for trucks in a bulletin...

 

 

LOCKING DIFFERENTIAL LUBRICANT (SERVICE INFORMATION) #91-4-109

SUBJECT: LOCKING DIFFERENTIAL (G80) LUBRICANT - (SERVICE INFORMATION)

VEHICLES AFFECTED: ALL LIGHT TRUCKS EQUIPPED WITH G80 REAR AXLE ALL YEARS

Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop.

This condition of alternate engagement and disengagement of clutches in differential assembly is usually caused by contaminated axle lubricant.

To correct this condition, drain and refill the rear axle with SAE 75W-90 GL5 (P/N 12378261). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life.VEHICLES/COMPONENTS INVOLVED: ----------------------------- Some light duty trucks equipped with locking rear axles, RPO G80.

SERVICE PARTS INFORMATION:

Part Number Description ----------- ------------------ 12678261 Lubricant, Rear Axle (1 litre)

Parts are currently available through CANSPO.

WARRANTY INFORMATION:

As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section OB, for further details on change intervals.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.

© Copyright General Motors Corporation. All Rights Reserved.

 

How the G80 works...

 

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 open diff 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.

[ryan_hermanutz]

Try an Auburn Ected unit. At the flip of a switch you can go from an aggressive limited slip to a fully locked Spool for maximum traction.

[steiny93]

Do they make an Auburn Ected that will fit in a 2500hd?

I'm not seeing one listed