It appears only my front wheels are engaged. Noticed while driving in snow that rears wheels don’t engage and only front wheels spin.
2002 Vehicle has 180k.
Please advise
2002 Vehicle has 180k.
Please advise
Does your vehicle have functional traction control? Has your vehicle been fitted with a center diff lock? Like blue said, do you have a rear drive shaft? What type of tires are you running in the snow and how much snow was there?
My understanding of the way open differentials and an open center differential works is that power will go to all wheels until one loses traction then that wheel spins and the others lose power. This is because of how a differential is designed. If you lock the center diff, the power goes to both front and rear axles evenly and you gain the ability to have one wheel spin in either the front or the rear while the opposite axle still moves forward or backward. With traction control in a DII you get the brakes automatically engaging to trick the diffs into thinking the spinning wheel(s) have traction sending power back to the wheels that lost it when wheel spin first began.
From what you described I cannot tell what is happening because my understanding of how diffs and wheel spin work is that for you to have two front wheels both spinning at the same time you’d have to have installed a front locker, locked your center diff, and removed your rear driveshaft. I doubt you drive around like that so it’s difficult to tell what’s happening.
If your front tires are spinning one at a time, e.g. front left spins, gets traction, front right spins, gets traction then the left begins again, and you’re not physically moving forward while driving in snow, then I’d say it’s time to upgrade your transfer case to one with a CDL or make a ghetto lever if yours has the CDL nipple. Another option is to buy some new tires with better winter traction. It sounds like you’re at the limit of the traction control and need to upgrade something, but I’m assuming what you described is missing details.
Will check when I return to cold hinterlandsAre you sure both front wheels are spinning at the same time? Ussualy when stuck you can see one front and opposite rear .
Has your Disco central diff locking ?
Regards
Kenneth, I really appreciate your write up. The traction control light came on and has stayed on. What should I look to next?I'll add just a bit for context, in case someone needs it in the future:
Center differential:
This allows the front and rear driveshafts to rotate at different speeds, obviously; but there's a reason for that. As a vehicle moves through a turn, the rear axle tracks closer to the apex of that turn than the front axle. Some will have noted in life that it's easier to scrape a rear wheel on a curb then the front, and this is why.
What that means is that the rear axle is not actually traveling as far as the front axle. Both rotate at different rates, as a result. This is the only reason you can pilot a vehicle through a turn while maintaining traction. Indeed, the "lack of traction" is where you're traction is coming from.
Were you to lock that center differential, it fixes both driveshafts at the exact same RPM. The front and rear tires cannot rotate at the same rate the road is going past. If it helps, think of tires as paint rollers. They must lay paint down evenly at the same rate they are rolling along the road, and in order to do that, the RPM needs to be variable.
Locked, some or all of the tires are now resisting the motion of the vehicle. Some paint rollers are just dragging paint instead of rolling it down, and anyone who's ever used a paint roller knows that this immediately alters friction. Even if the tires are not chirping, it's happening. When you get to the point at which tire deflection can't absorb it, you'll either get that chirp or... If you're in slushy conditions, control will be severely compromised, and it can happen quickly.
When you see people driving in rallys, on tracks, or in ice with traction aiding differentials of any variety, you're seeing someone that knows darn well they're literally gambling traction in one scenario for another, and they have to drive differently to make it work. They must approach and leave turns differently, as well.
Front and Rear Differentials (third members, etc...):
These do the exact same thing, but from side to side. Again, each wheel on an axle needs to rotate at different speeds. Being open allows them to roll at whatever speed they wish without smearing that imaginary paint. Again, if you limit or remove that differentiation (slip), you're forcing them to do things they don't want to do.
I've got Quaife differentials in my DII. They're not going to be as grabby as a limited slip, nor as capable as a locker; and I like that. By allowing more differentiation than the other two, the vehicle is more stable in sweeping turns and close to the limit than it would be otherwise; but it's still compromising that perfect stability open differentials allow...
...until you exceed the handling limits of the vehicle. At that point you're breaking traction, and at that point these differentials serve a purpose: They take that broken traction and render it less relevant. Each differential technology sits in a different place on that scale. Mine are closest to open differentials. Limited slips are closest to lockers.
Land Rover:
Land Rovers are not four wheel drive vehicles. They are All Wheel Drive vehicles. Yeah, yeah; "Permanent 4X4"... Whatever. Marketing nonsense. All that means is on most you can lock the center. It's still an AWD car. 1% of your customers using a feature 1% of the time doesn't win you a new segment, Land Rover. It just confuses people.
AWD is not a cop-out; it's great for many reasons, but chief among them is having the utility of all four tires as often as possible, without upsetting stability. You're much less likely to become stuck in the first place, and you get the benefits in normal conditions. Think of it as an over-built, over-sized Subaru. All the same benefits, with a fair bit of the same drawbacks. These weren't designed for rock-hopping. They just happen to be quite good at it when appropriately configured.
I know the information here may seem like a given to some, and yes, it's obvious to many people; but it's been obvious for so damned long that nobody bothers to explain it anymore, and without explanation, how are people to know?
If I got anything mixed up in there, let me know. I've got some focus difficulties of late, and I can get things backwards on occasion.
Cheers,
Kennith
He’s got no 4WD in that 2002 car. Since he’s got the three amigos, his ETC isn’t working. So he’s rolling AWD with no TC, hence the traction problems.Search for "3 amigos" in the forum. This is an ABS typical trouble. It is an additional issue more related with brakes. 4WD should still working.
Regards
Kenneth, I really appreciate your write up. The traction control light came on and has stayed on. What should I look to next?