Chevy Express 3500 - Locking Differential

[dhalltoyo]

GM techs tell me that their locking differential system has a clutch pack that locks the differential when one of the wheels breaks traction or senses slippage.

I guess I can understand the advantage if I were pulling a heavy boat up a wet boat ramp, but considering my driving style (slow and steady) I can not really say if my other 3500 Express with a locking differential has been any tangible benefit.

I subscribe to the KISS (Keep It Simple, Stupid) method when considering operational costs.

I am thinking, "Do I really need the extra components of the locking differential?" "Do the benefits outweigh the extra weight?" "Will there be a reduction in fuel economy with a locking differential?"

As I am in the process of ordering another vehicle I want to make sure that I get those things that will make it more efficient.

EO has an excellent group of folks that really know their way around vehicles. I would appreciate your thoughts on this matter.

 

[LDB]

I saw a segment on that on Motorweek or one of those shows. It looked very impressive. They did a demo using wet pavement but also pointed out it could have the same benefit in snow or ice. I decided if I ever got a van chassis for an Aerocell it would be a GM product with option G80. What I saw wasn't a GM in house video. It still could have been slanted in their favor but I prefer to think they have no agendas on the show and it was not biased. For me, if it helped even once during winter it would be worth it. Good luck with your decision.

Leo Bricker, 73's K5LDB, OOIDA Life Member 677319
Owner, Panther trucks 5508, 5509, 5641
Highway Watch Participant, Truckerbuddy
EO Forum Moderator
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Support the entire Constitution, not just the parts you like.

 

[x06col]

I am a believer in a locker on anything. The weight and cost is negligible. You may have already benifited from the locker on your present machine, and did not realize it. One tow bill in the future would pay for it, not to mention the aggrivation of being stuck. How much is the option on the chevy? I just ordered a ton Dodge and the locker on it cost $325.

 

[greg334]

Does it matter to have one?

Yes, even with your driving style, the mechanics of a limited slip differential (that is what it really is) is not important but the safety issue in driving in rain or snow or anywhere that you can slip.

Cost of operation? Not really a factor. I would venture to say that the additional cost in maintainance (if any) would outwiegh the safety that it provides.

Weight?

If there is more than an addition of 5 pounds added on to the weight, I would worry about GM itself and go to Ford.

And if you see a reduction in fuel mileage because of this option, I also would question the ability of GM to engineer the truck the right way. You should not see any changes in mileage unless the option is to a specific gear ratio.

I have to add that this goes inside of the differential and it usually contains springs, steel disks and disks with transmission band material glued on them all put into the carrier of the differential. It is sort of an automatic thing that ‘senses’ axle slip, but more akin to a speed limiting device seen on some steam turbine systems. Technically speaking, this little device limits the slippage but not locks the differential, that’s a different device.

Oh and GM DID NOT invent this as many think they did.

 

[Moot]

I am on my second Chevrolet van. Neither had a locking differential. I couldn't justify the extra cost especially since I went with chrome bumpers on the new van. Also I wanted power adjustable heated mirrors. That option came packaged with power windows and door locks. Two items I did not need or want. But now that I have them, well I must admit they are convenient.

David, I hope you are looking at the long wheelbase 3500. In my opinion it is better suited to expediting than the short wheelbase model.


Have fun putting it all together!

 

[greg334]

Moot, don't you just love those packages?

 

[Moot]

Sure would be nice if everything was a la carte. I can understand some of the packages, but most are extortion.

 

[dhalltoyo]

Great answers!

My only reservation is based upon previous driving experiences with cars that had "Positive Traction". When you accelerated forcefully, and both wheels were locked, the car would fishtail. The same car without PT would only have one of the wheels slip.

As I never goosed the other express 3500 with the Locking Differential I am sure how that vehicle would react.

 

[dhalltoyo]

XCOL,

You ordered a 1 ton truck or van?

 

[LDB]

The G80 option is $325 so on a 36 month purchase it's about $10 a month and on a 60 month purchase it's about $6 a month. They did a few different test demonstrations on the show I saw. The tests were in a 2500 pickup but results should be very similar. Some of the tests were against 4 wheel drive versions of the same vehicle. They also had a 2 wheel drive without the G80. In extreme offroad conditions with one drive wheel well off the ground the G80 truck went right on like nothing. The one without was stuck. On wet pavement with standing water the G80 truck had about 3 or 4 inches of revolution of the tire slipping and then went on like nothing. On a steep incline with rollers to represent ice conditions the G80 had about 1/4 revolution of wheel slip and then went right on up. The 4 wheel drive without G80 was stuck. I wouldn't have one without it and would skip one buffet a month to pay for it if that's what it took.

Leo Bricker, 73's K5LDB, OOIDA Life Member 677319
Owner, Panther trucks 5508, 5509, 5641
Highway Watch Participant, Truckerbuddy
EO Forum Moderator
----------
Support the entire Constitution, not just the parts you like.

 

[unorthodoxneon]

I have yet to see a locker be put in a factory vehicle, never has dont think ever will really. A locker has a new driving habit you have to get use to, especially when turning corners and giving it gas, your locker will chatter and the wheels will chirp/hop going around corners.

I think its actualy a limited slip that is being added to the package. I would spend the extra money to have an LSD installed in a vehicle espeically if you drive in the rain/snow/ice. I have a factory LSD in my Dakota and i love it compaired to an open diff. What it should do is if one wheel happens to lose traction the other wheel will get some of the power. On an open diff the wheel with the least amount of traction gets all the power. Now if you split that to a wheel thats getting some traction you will be able to move alittle without just sitting in one spot.

For maintance you will have to have the rear end serviced regularly and have limited slip additive put in to keep the clutch packs from wearing out. The limited slip could also go after time and need to be replaced. I also reccomend running synthetic fluid in your diffs as it helps with gas mileage and keeping the rear end/LSD in good working condition.

Like i said i like my LSD in my dakota. It helps in snow and i dont really have to rely on putting it in 4x4 to get around.

 

[unorthodoxneon]

Well i looked up the info and it talks about being a Locker and a LSD all in one. I guess i'll have to do some research about it. But if i had the option i would get it.


EDIT:::
Not much shows up about it but its also called Command-Traxx which seems to be made by Eaton. It only locks up in conditions that warrent and then is an open diff during driving on normal pavement or cornering. Also doesnt need any special fluids. Sounds like a nice system.

 

[dhalltoyo]

What brand of synthetic fluid are you using the your expediter?

I was not aware there is a "limited slip additive". Who makes the additive?

 

[60MPH]

I only use amsoil all the way around engine,trans,rear & grease, if they made a ps or brake fluid I would probley go with that to. I am a stickler for maintenance I change oil at 10k, trans and filter at 60k, rear at 60k, ps,brake fluid & coolant at 100k. I know I have been told 1000 times I am wasting money changing everything so soon but this is my house and money maker so I take care of her!!! Oh yea I have the LSD in my chevy and love it.




60 MPH ALL DAY-EVERY DAY

 

[unorthodoxneon]

For an amsoil powersteering fluid you could probably use transmission fluid in it.

In my Dakota I run Amsoil in everything that will take it. I also add lucas aswell.

 

[greg334]

if you use DOT5 brake fluid, it is a waste of money to change it. That is a silicon fluid and does not asorb water like the DOT3 does.

 

[60MPH]

I have always had the ps & brake fluid flushed at 100k for all my vehicles I guess it is just habit, plus when you flush the systems you are getting rush and dirt and what have you out of the system, oh yea one other crazy thing I have done at every 250k is I have the a/c system evac'ed and have fresh freezzzzoooonnnnn put in the system, gotta have my a/c work'in at it's best




60 MPH ALL DAY-EVERY DAY

 

[Moot]

Like i said i like my LSD in my dakota. It helps in snow and i dont really have to rely on putting it in 4x4 to get around.

Sounds like a hallucination, man. Uh, don't get like called in for a random drug test. Bummer.

 

[dhalltoyo]

60 MPH,

Didn't you have a Chevy gasser when we first talked?

I thought you had told me that you ran Amsoil after an engine rebuild in that van and it "ticked" so loud you had them drain it out and replace it with non-synthetic.

 

[60MPH]

you are correct I had a 2000 gasser when I met you in commerce ga. it turned out not to be the oil, the tick was a lose rocker arm I got it fixed about 4 weeks after I saw you and went back to amsoil then ended up getting rid of the van in nov-06, thats when I got this new one with the d-max. I was suprised that a brand new gm engine "not a rebuild" had a lose rocker arm a bad water pump and the rear main seal started leaking at 20k I probley would of done better with a rebuilt 350 and could of saved some money, oh well its in the past now

hind sites 20/20





60 MPH ALL DAY-EVERY DAY