How does limited slip work?
I recently noticed that when one rear wheel loses
traction like when you go over a mound of dirt.
One wheel slightly in the air and the other on
solid dirt. The wheel in the air spins and no
power goes to the wheel firmly on the ground. I
thought that limited slip would prevent this.
Service Manager at my dealer says this is "normal".
Does anyone know if this is true or not?
traction like when you go over a mound of dirt.
One wheel slightly in the air and the other on
solid dirt. The wheel in the air spins and no
power goes to the wheel firmly on the ground. I
thought that limited slip would prevent this.
Service Manager at my dealer says this is "normal".
Does anyone know if this is true or not?
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Comments
If this was a regular differential, this would be normal. But a limited slip differential should only let one wheel spin a little bit before it begins to transmit power to the other drive wheel.
I wouldn't let them get away with giving you the old "that's normal" routine. I would either take it to another dealer for service, or escalate the problem through higher-ups (regional or district manager). Good luck.
Bogieman
Another test would be to find a road with a muddy shoulder. Park with one wheel in the mud, and the other on hard pavement. Then nail the throttle. You should be able to take off without a problem if the limited slip is working correctly. A regular axle will just spin the tire in the mud and go nowhere.
I had a Ford Ranger with limited slip that worked almost too well. The rear end would skitter around tight turns, because it wouldn't "differentiate" enough. And it would leave two equal length black rubber patches on the pavement if I burned rubber. If I got stuck in sand, both back wheels would be buried. It would allow little or no spin before kicking in the other wheel. Compare that to my F150 with a regular axle, that would leave only one rubber patch on pavement, and would only bury one wheel if I got stuck in sand.
I have a Chevy truck now, with a locker. It will spin one wheel for a second or two before it decides to kick in the other wheel. And you can definitely feel it when it does. It allows much more spin than the limited slip does before transmitting power to the other wheel (from my experience).
I just visited the Toyota web site, and couldn't find any mention about what axle type the T100 has. They don't list options for that either (other than axle ratio).
You're right about the regular axle on a 4X4. It is effectively only 2 wheels driving (one front, one rear).
I have friends that have SR5 trucks, they came with the regular axle. One of them installed an aftermarket locker differential, and that made a world of difference on where he could go off road. I don't know if there are aftermarket kits for the T100. You'll have to ask around I guess.
Good luck.
Should I get the locking diff?
Will it adversely affect gas mileage, performance, or handling?
Performance will be improved if your vehicle has enough power to spin a single wheel when accelerating (laying rubber). When both wheels put the power to the ground, you can launch quicker without spinning the single wheel.
I would think handling should be more predictable as you come out hard (heavy gas) from a low speed sharp turn, because the shift of the vehicle weight in either direction will have the same result. In my F150, if I give it too much gas making a low speed sharp right hand turn, by back wheel (passenger side) wheel break loose and spin like crazy because most of the vehicle's weight is shifting to the front left. On the other hand, if I do the same thing making a sharp left, I can come out of the bend quicker because the right side of the truck is receiving the weight shift which puts more downforce on the right rear tire. My Cobra on the other hand (with posi-traction) lets me accelerate out of left and right turns the same.
is the following discussion:
"Many brands and styles of posi devices are available for different types of axles. They all share one
common characteristic that helps them give more power to that wheel on ice we talked about earlier.
Essentially posi units use clutches inside the device that press together when power is applied to the axle.
This forces both wheels to try to spin at the same speed. However the main drawback to posi units is that
they can only overcome a certain amount of traction difference between the 2 wheels. For example if we
had one tire on ice as before and the other on dry pavement the posi would probably get us moving. But,
if the truck was pointing up a sharp hill or the tires were in a small rut we would probably remain stuck.
The reason is that even with power applied, the clutches would probably slip before the wheel on
pavement would begin to turn"
I hope this answers the original question. I am surprized that no one more experienced than I jumped in. Maybe its no worth getting flamed.
"Most posi units are designed to try to keep both wheels turning, but still allow one wheel to turn slower
than the drive shaft in order to allow the vehicle to corner smoothly on the road. For better traction a posi
unit is always superior to the open differential. They usually require a special lubricant or additive in the
gear oil to function correctly and will become less effective as the clutches wear out. However, most can
be rebuilt for a reasonable cost. Keep in mind that a posi in good condition will likely cause the vehicle to
fishtail and slide to the outside of a turn on very slippery surfaces like snow or ice, so use caution under
these conditions. There is no substitute for prudent driving."
I have a 95 Jeep cherokee with a limited slip and haven't noticed any fishtailing but then I did't know until now that it was a possibility and my memory is not that good. 8:) happy four wheeling.
You can also look up your local 4x4 shop in the yellow pages. My town (Salt Lake City) has several 4x4 equipment shops including Mepco and several shops who install and switch axles. Also search the internet through your favorite search engine for "4x4" or "four wheeling" or "locking transmissions".
which axle (GM10, 12, 14, or ???) are being used
on the '99 Sierra/Silverado. Anyone has any info
on this?
Thanks,
Tung
dave40 - drove a new Silverado 5.3 with lim slip with only a few miles. Drove around a snowy parking lot at speeds up to 40. Truck was plenty loose at higher throttle settings, and both rear tires would break loose. Maybe it worked so good 'cuz it was new.
There is another option to the limited slip. I believe it is ARB and others I am sure, that make a "locking" differential. The advantages to the "locker" are the wheels turn together, no clutches to wear out, and you only engage it when you want it, ie. climbing up a slick boat ramp. The disadvantages would be, additional hardware to engage and disengage it, you have to "turn it on" for it to work, it is not just waiting around for a wheel to start slipping. Cost should be comparable if costs in the previous posts for limited slips are close.
I know that on more recent Landcruisers and some other 4WD vehicles, there is an option for a "locking center differential". Sounds like that might have forced power to the front wheels, even with the rear wheels off the ground. So, my other question is, does the autotrac system in the new Sierra/Silverado have what amounts to a locking center diff? If not, how do they handle this type of situation?