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Traction control of a spinning wheel

1015 Views 26 Replies 7 Participants Last post by  DankoRav
I'm sure this has been asked before but I just can't find it, sorry.

Imagine one front wheel is in the air. One rear wheel probably will be too. Car is stuck, fair enough, that's what happens without axle LSD or diff lockers.

That lifted front wheel just spins. Does the traction control brake the spinning wheel at all, or just cut engine power? In my experience it does not brake the spinning wheel. Is that to be expected on the 2008 Limited?

You can use the handbrake gently to slightly brake a spinning rear wheel, mixed success. Two handbrake levers, one for each rear wheel, would be helped in the absence of a diff lock. Not likely though... Any other tips to move on from this situation, rather than more entry speed? Thanks.
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You can have mixed situations, I had situations were the engine cuts power and it just stalls on my manual 5-speed, or situations were I had a very muddy place to go out and you literally feel the horrible braking on the spinning wheel... is terrible really, make the whole car shake and vibrates but gets the job done.
 

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Thanks, good to know. An old RWD car I had had great traction control. Open rear diff but great grip in the snow unless both rear wheels broke traction.

Your 4WD rav4 explanation makes sense. Sounds like the traction control will get it moving if one wheel is on ice etc (although with a locked centre diff that's a bit unnecessary). Sounds like it won't help with two lifted wheels. Either need a rear diff lock (no), more articulation (no) or something else (handbrake or left for braking to control the spin a bit).
The center clutch is completely necessary on this car, when you decide to lock it, it will really lock front and back and not wait for a spin to act and lock rear wheels... they will be already locked... this helps a lot and is even more noticeable when you drift on snow and mud, the car tends to turn into the corner when the center locked instead of under steering and then locking and then the traction control becomes crazy, start to beep and cuts power... this car with the center clutch locked is more effective and fun
 

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There is no "central clutch".
Only one electromagnetic coupler at the rear diff.
that electro magnetic coupler, is not a bunch of discs that are compressed together?

EDIT:

After some research and investigation, is, an centre clutch and this is how it looks like:
Automotive tire Camera lens Automotive design Motor vehicle Engineering


Source: Toyota all-wheel drive. ATC / DTC coupling


es agreed, that's great on flat surfaces. It's when a bit of articulation is needed that I'm asking about. With no rear diff, and the traction control not braking two spinning wheels (one on each axle) then alternative ideas are needed! Thanks.
You are asking too much, two oposite wheels on the air is more than you should be handling with this tall car.
 

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So even if the electromagnet is activated, the clutches don't get pushed unless is a difference in rotational speeds of front and rear axles. Only then the cam balls get pushed and bind the clutch surfaces.
Thank you for the bunch of information you provided.

Even tho,when i push the lock button, is different, very obviously different from not locked when i'm on slipping situations like mud or sand... when is not locked, you can clearly feel the rear wheel kicking in when front slips, but locked is "locked"... i understand that is a clutch and it can slip on very high torque, but that would imply that the discs are damaged or beggining to fail...
 

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I had the same reactions while testing in deep snow shortly after buying our used RAV4 with an automatic.
When I purposely got it stuck sometimes it would cut the power such that one front and one rear tire would spin lazily even at full throttle. Other times if I got it to spin a rear tire (which must mean a front was spinning too) I got the hard literal pounding as the ABS tried to stop the spinning wheel. Sounded and felt like something was gonna hammer itself apart. I got out the snow shovel!
This is exactly what happens, i will be on the seek of snow soon enough, and probably will find more snow than, when a first got my RAV4, since that time i got propper tires, chains... now i will buy maxtraxs, and skid plate protection and all the stuff i think i need to don't get AS stuck... and with that i will confortably test all the possible situations i could face on my travels... since as now i have been doing mild off roading because i don't want to find the limits much away from home...
 
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