4 wheel drive or 2 wheel with locking dif

[HighLoader]

I am looking at the 07 Chevy 2500HD, ext cab long bed, with the Duramax and Allison Trans. I am stuck on wheather to get 4 wheel drive or just 2 wheel drive with the locking differencial. I will not be towing very often, maybe 3 or 4 times a year. I will be towing a three horse trailer with horses that weighs about 7300lbs and sometimes a travel trailer that is 8700lbs dry and maybe 10,200 loaded. I live 5 miles back on a dirt road. I will be towing from southern California to northern Navada and back. It is about 12 hours one way. Is there a big advantage to having 4 wheel drive? Is 4wd a rougher ride than 2wd in an 07 Chevy? I would hate to get stuck in the mud or snow pulling three hungery horses. I have heard good things about the Chevy rear locking dif....is it enough to keep me out of trouble??? What do you think and what would you do???

Thanks, Brian

 

[MikePA]

Is there a big advantage to having 4 wheel drive?

'Big' is a subjective term. 4wd will get you out of trouble easier than 2wd. However, 4wd is not a 'cure all'. 4wd might tempt you to get into situations you shouldn't.

Is 4wd a rougher ride than 2wd in an 07 Chevy?

No.

I would hate to get stuck in the mud or snow pulling three hungery horses.

This why we have a 4wd Chevy K1500. We've taken the horses (3), in our GN trailer plenty of places, some of which you wouldn't think would present traction problems. For example, a gently rolling grass pasture. We had to stop going up a slight incline to allow someone else to park. We went to move, and the rear wheels spun. Popped it into 4wd, and off we went.

I have heard good things about the Chevy rear locking dif....is it enough to keep me out of trouble???

IMO, no. We have a limited slip, which is not the same as a locking diff, neither are as good as 4wd.

What do you think and what would you do???

If you can afford it, I'd get 4wd.

 

[crbr]

Bear in mind, you'll be looking at a single axle drive with limit slip diff. or a two axle drive with limited slip diff. Unless you install a locking gear in each housing, you'll never see a true 4 wheel drive.

Personally, I'd anty up for the two axle drive. At that point of money, it's becomes a moot point. I have a two axle drive Duramax / Allison.

With that said, there are several different setups within the new 07s that you may want to look at. Different diesel engine options (HP) and different transmission options (5 speed / 6 speed).

PM me if you'd like a link to a very informative Duramax discussion forum. Then you can know you've done a thorough research. Those guys know a lot.

Now with all of that said, personally I'd go with a crew cab. No need to say a lot to try and convince you, but they are very convenient. I like the crews...However, I miss the long bed from my previous truck.

(click on the thumb image)

 

[Renze]

4wd, even when not engaged, will cause a slightly higer fuel consumption on the highway due to more moving parts.
a limited slip differential doesnt give 100% lockup in dirty conditions, but doesnt consume much power on highway speeds either.
For most conditions, the limited slip will give you more wheel torque distribution than a set of wheels can convert into traction. So no additional benefit for the fully locking diff unless you have rough profiled offroad tires.

If i was you, i'd look at either 2wd with limited slip if you're doing a lot of traveling, and 4wd if you can afford it, do lots of offroading and little highway travel.

 

[Builder]

I am looking at the 07 Chevy 2500HD, ext cab long bed, with the Duramax and Allison Trans. I am stuck on wheather to get 4 wheel drive or just 2 wheel drive with the locking differencial. I will not be towing very often, maybe 3 or 4 times a year. I will be towing a three horse trailer with horses that weighs about 7300lbs and sometimes a travel trailer that is 8700lbs dry and maybe 10,200 loaded. I live 5 miles back on a dirt road. I will be towing from southern California to northern Navada and back. It is about 12 hours one way. Is there a big advantage to having 4 wheel drive? Is 4wd a rougher ride than 2wd in an 07 Chevy? I would hate to get stuck in the mud or snow pulling three hungery horses. I have heard good things about the Chevy rear locking dif....is it enough to keep me out of trouble??? What do you think and what would you do???

Thanks, Brian

Brian,

I just got my 3500HD 4x4. It comes satndard with a locking differential. I my book, it's an excellent unit. First off, it's not a limited slip. Ford units are limited slip. My Ford only works sometimes. When it does, clutch packs engage so that the wheel that's spinning locks up with the stuck wheel and helps get you unstuck. The power transfer is slower, the clutch packs slip somewhat, so you lose power transfer.

In the GM HD's, the rear locker is a true locker. It mechanically locks the spinning axle side to the non-spinning side to get you unstuck. There's no clutch packs to wear out and the power transfer loses very little since there's no clutches to slip.

I have already experienced how much better the Gm unit works than the ford unit. I got my front tires off the pavement in a culvert, but my back tires were still on wet pavement. I put my GMC in reverse. At first, the rear tire spun, maybe a 1/2 revolution, then with a distinctive "thuk", the other rear tire locked-up and very quickly pulled me backwards.

In similar situatuations, my Ford L/S would not work as well. In fact, after about 50K on my Ford, the L/S is pretty well shot.

So the GM locking rear works very well, if all you require is 2WD. All that said, I wouldn't buy a truck without 4WD, it's worth every penny and it brings you better resale value since, too.

I think you'd be happier and more relaxed with it knowing you can get across wet fields than "white knuckling" with a 2WD.

 

[crbr]

Brian,

I just got my 3500HD 4x4. It comes satndard with a locking differential. I my book, it's an excellent unit. First off, it's not a limited slip. Ford units are limited slip. My Ford only works sometimes. When it does, clutch packs engage so that the wheel that's spinning locks up with the stuck wheel and helps get you unstuck. The power transfer is slower, the clutch packs slip somewhat, so you lose power transfer.

In the GM HD's, the rear locker is a true locker. It mechanically locks the spinning axle side to the non-spinning side to get you unstuck. There's no clutch packs to wear out and the power transfer loses very little since there's no clutches to slip.

I have already experienced how much better the Gm unit works than the ford unit.

I can agree to a point, Some mechanism has to engage or disengage the differential from a single wheel to a two wheel drive (on the rear axle). If it's a locker, it will stay in place or it has to have some other means of engagement / disengagement.

I do hear what you're saying and my ignorance may show a bit here, but there's a slip mechanism here somewhere.

I'll do a little eduMacating to myself later today.

However you do make a great point.... "how much better the Gm unit works than the ford unit."

 

[Renze]

At first, the rear tire spun, maybe a 1/2 revolution, then with a distinctive "thuk", the other rear tire locked-up and very quickly pulled me backwards.

Have you experienced these "thuk" 's when just going down the road, in corners ? From the Volvo 240 racing scene, people complain about "thuk"s with self locking diffs in corners, with +300hp racing bricks. These came facory fitted with a Dana 30 rear end, the same as used in some Jeep models.

 

[Builder]

Have you experienced these "thuk" 's when just going down the road, in corners ? From the Volvo 240 racing scene, people complain about "thuk"s with self locking diffs in corners, with +300hp racing bricks. These came facory fitted with a Dana 30 rear end, the same as used in some Jeep models.

Nope, quiet as a church mouse around corners.

I had a Detroit Tru-Trac "soft locker" in a Ford dump truck and it was the best. Locked-up tight when one wheel spins, but did it smoothly with a light "thuk". No noise on turns like a standard Detroit locker. The GM HD rear feels very similar to that.

 

[Jimbrown]

There is no limited slip in a GM g80 semi locking rear axel. It works on weights and if one wheel exceeds the other by a given amount it positevely locks up. No clutches at all.

The Eaton G-80 uses a centrifugal locking/unlocking mechanism that activates on one rear wheel spinning at only 100+ rpm than the other, but limited to 20 mph. It’s completely mechanical, and foolproof, to the point that Lexus could advertise it as the next invention of the wheel. We need to advertise this test, and the G80 at the same level, and we need to advertise that we’ve made it standard on Z-71’s since practically the beginning of time.

Since the G80 uses a physical/mechanical locking of the rear axle shafts, owners will not encounter the wear symptoms associated with friction-based limited-slips.

 

[workinallthetime]

long ago in rear diff class they had this cool vid.
1st truck - open diff
2nd truck -limited slip
3rd truck -locking diff
these were all 80's model trucks so thats how old the vid was but the facts are the same from then to now. they had a wet ramp that the trucks had to climb up from a dead stop.
1st truck pulled up the ramp until the rear tires made contact then it just had the 1 wheel squeel and didnt go up it at all
2nd truck pulled up about half way then the speed of the tires disengaged the limited slip due to rpm's at the tire (something like 2800) the limited slip "unlocks" at that speed
3rd the locker- had to stop at the top of the ramp, drove right up it no problem tires spun the entire way up.

im not aware of gm offering anything but either an open or locked rear diff in trucks since 92. i have seen the limited slip in trans am's and z28's but never in a truck.
like was said g80 is a locking rear diff that does not unlock until you stop the truck. bad thing about a locker in a 2 wheel drive is it tends to put you sideways on a slippery surface. if you have a locker and 4x4 then the most you can hope for is 3 wheel drive because gm does not put lockers in the front diff. as for the wheel hop in a corner with a locker ive seen it, this happens when you dont service your rear diff and things get sticky.

i will never own a 2 wheel drive truck again, love the insurence of the 4x4 and i have not noticed any decrese in mpg.
rides smooth and drives great.

 

[HighLoader]

Thank you for all the replys! The understanding I have is that the Chevy rear locking diff is not the same as the Fords limited slip and is much better. I had a few Fords, the last one was an 04 F250, and I was not impressed with the limited slip. I am wondering if there is anyone out there that has the Chevy rear locking diff without the 4wd? Do you wish you had 4wd?

Thanks, Brian

 

[crbr]

There is no limited slip in a GM g80 semi locking rear axel. It works on weights and if one wheel exceeds the other by a given amount it positevely locks up. No clutches at all.

The Eaton G-80 uses a centrifugal locking/unlocking mechanism that activates on one rear wheel spinning at only 100+ rpm than the other, but limited to 20 mph. It’s completely mechanical, and foolproof, to the point that Lexus could advertise it as the next invention of the wheel. We need to advertise this test, and the G80 at the same level, and we need to advertise that we’ve made it standard on Z-71’s since practically the beginning of time.

Since the G80 uses a physical/mechanical locking of the rear axle shafts, owners will not encounter the wear symptoms associated with friction-based limited-slips.

long ago in rear diff class they had this cool vid.
1st truck - open diff
2nd truck -limited slip
3rd truck -locking diff
these were all 80's model trucks so thats how old the vid was but the facts are the same from then to now. they had a wet ramp that the trucks had to climb up from a dead stop.
1st truck pulled up the ramp until the rear tires made contact then it just had the 1 wheel squeel and didnt go up it at all
2nd truck pulled up about half way then the speed of the tires disengaged the limited slip due to rpm's at the tire (something like 2800) the limited slip "unlocks" at that speed
3rd the locker- had to stop at the top of the ramp, drove right up it no problem tires spun the entire way up.

im not aware of gm offering anything but either an open or locked rear diff in trucks since 92. i have seen the limited slip in trans am's and z28's but never in a truck.
like was said g80 is a locking rear diff that does not unlock until you stop the truck. bad thing about a locker in a 2 wheel drive is it tends to put you sideways on a slippery surface. if you have a locker and 4x4 then the most you can hope for is 3 wheel drive because gm does not put lockers in the front diff. as for the wheel hop in a corner with a locker ive seen it, this happens when you dont service your rear diff and things get sticky.

i will never own a 2 wheel drive truck again, love the insurence of the 4x4 and i have not noticed any decrese in mpg.
rides smooth and drives great.

Thank you. I stand humbly educated on this topic.

Still remains, that there isn't a true full-time 4-wheel drive truck without a locking gear installed. My **** compulsive opinion is that the terminology "4-wheel drive" just isn't completely true.

 

[workinallthetime]

crbr
you are correct there is no true 4 wheels pulling trucks availble without a locking front diff that i am aware of.
the problem is that a true 4 wheel drive can not drive on the dry streets due to turning problems. if you are locked into 4 wheels and go to turn on dry ground you will probably break something in the front diff, due to one wheel is bearly turning and one wheel is turning alot. people who buy trucks and drive them everyday would be breaking stuff left and right when they pulled out of the mud ontop the street.
the rock crawlers and mud buggies have lockers and a straight axel front end. this is something you could install yourself but should not be run on the dry streets for those reasons.
im sure there are specialty trucks built with front lockers but not something you would want to drive day to day.

i use my auto 4x4 function in the heavy rain, this keeps the front end from pulling to one side when you hit a big puddle, i use 4 hi in the snow and mud and 4 low to pull in the dirt .

lets get muddy !!!
woohooo tornado warning till 5 around here, i once met a guy from cali who was lost and asked for directions.
he said "i dont mind when the earth shakes but when stuff starts falling from the sky im scared, how far away is that tornado?"
i said " ohh its 15 miles that way and headed west your fine"
lol

 

[workinallthetime]

high loader,

i would get both the locker and the 4x4, that is a great combo and i always get both, the cost is a bit more but you will be very happy im sure. dont forget to change your spin on trans filter at 3k and transfer the magnet from the old filter to the new.
check your rear diff fluid and make sure it is full every oil change. they vent when they get hot sometimes.

 

[crbr]

......lets get muddy !!!
woohooo

I have been down that road too my friend

:tiphat:


This is one of an 11-vehicle jaunt. Only one guy had lockers. He made it through this hole with ease, the others had to skip through it the best they could. The bearded guy is not me...

(click on thumb)

 

[Builder]

A 4WD truck with true lockers front & rear would be a catastrophic failure on ice or packed slippery snow. Ask me how I know.

I've plowed snow with dozens of differently configured trucks and the easiest to handle is a 4x4 with open rears, next best is a 4x4 with a gentle rear locker or L/S.

I know-I know, everyone's gonna disagree, but you can actually have "too much traction" while plowing or driving over ice. Just enough traction is the best. The reasons are many, but the most important are:

1. A truck with hard lockers that start to engage on ice will tend to start the truck into a sideways sliding motion and you'll end up facing the traffic that was once behind your tailgate with a wet feeling in your pants. A front hard locker will just slide sideways in a turn on ice causing a loss of control.

2. Since there's a lot of turning involved in plowing, the wear on the locking rears, the tires and the axle assemblies is substantial.

The best plow truck would have an excellent set of snow tires, maybe even some studded snows and a nice 1/2-1 ton weight in the bed.

Very predictacle, easy on wear & tear and still gets great traction.

Hard lockers are best in deep mud, off road work where there's no sliding sideways across frozen pavement getting you or someone else killed.

 

[workinallthetime]

i agree with l39
i had a guy tell me the best plow truck he had for that deep oklahoma snow,lol, was a 1/2 ton, chains or studs, and weight. seems crazy till you think about it.

 

[Z-Michigan]

We debated the same thing before getting our Dodge Ram 2500 to pull a 3-horse slant. We were told by relatives with horse trailers that we needed 4wd. They were right. We use 4wd much more than I had expected when moving the horse trailer off pavement, even in dry conditions that would otherwise provide good traction. I think 2wd would be ok if you were only ever on pavement or had lots of 4wd trucks nearby whenever you were off pavement. Otherwise, I think 4wd is worth the cost.

 

[KAB]

Thank you for all the replys! The understanding I have is that the Chevy rear locking diff is not the same as the Fords limited slip and is much better. I had a few Fords, the last one was an 04 F250, and I was not impressed with the limited slip. I am wondering if there is anyone out there that has the Chevy rear locking diff without the 4wd? Do you wish you had 4wd?

Thanks, Brian

I had a 90 K series Blazer for about 4yrs. In 4 yrs of winter driving I NEVER used 4wd for daily driving (Snow belt area of NE Ohio). The G80 locking diff did quit well. I would engage 4wd thelp prevent tearing up a soft yard when I need to drive through one. The only time that I used 4wd when it was truely necessary was when I was to lazy to walk through snow plowed up blocking a driveway that I wanted to access one cold winter day. (I should note that my neighbor, who does snowplowing and bought the Blazer from me, said it worked really well for him this past winter.)

For the Envoy (w/G80) that we still own I had my wife put it in A4wd on snowy days. I would use 4wd on snowy days when I needed to cross a busy road. That was until I replaced the original tires at 50,000 miles. The new tires have made a big difference. I also use 4wd just like I did with the Blazer, but due to the shorter turning radius I have to be careful with binding.

If money is not an issue then the extra price for 4wd could be a cheap, time saving purchase if the need for 4wd should arrive.

Kurt

 

[john_bud]

There is one more advantage of 4wd in the 2500 HD. It has a 4wd LOW range. If you want to slowly move a heavy load at idle or just above, that is the way to go. It also gives you much more control backing up a loaded trailer.

I have a '03 2500 duramax/alison 4wd with locking rear - 17.59 mpg lifetime average with 20,000 of 60,000 miles towing 9500# of trailer. IF you want milage, well can't get it anymore. You need a manual transmission (only from Dodge) and 2wd and you need to use the non USLD fuel. I am seeing a 1 to 1.5 mpg loss this year with the only known change being the change in fuel. Still, it beats the milage with an 8.1 or 6.0

Hey Workinallthetime - hows the milage with the variable displacement engine?

jb