Friend got his AWD towed.... how to check??

[lt1camaroman93]

My buddy just got his AWD DSM towed and they towed it from the back wheels with the fronts on the ground and the trans in neutral. Nothing is locked up, car seems to drive ok, but if I put it up on a lift and spin a front tire, the back does not spin and vise versa. What all should I do to check from bad/broken stuff? The towing company already said they are liable for damages done so we want to get the sorted out asap. Thank you for your help.

 

[alice]

Turn the rear wheels and the fronts should turn. Turn the fronts and the rears shouldn't turn. Somebody chime in if I am wrong.

 

[luvmygst]

Put the car in the air w/ all 4 wheels off of the ground and start the car and put it in gear, see if all 4 wheels spin. (do it VERY slowly so it doesn't fall off). Thats what I would do. If the car drives fine then the V/C is still good if it goes out the car will not move. How far was the car towed? very far at all and it put alot of stress on the center V/C. I would have them replace it they should have known better than to tow an AWD with 2 wheels on the ground. My .02

 

[lt1camaroman93]

They towed it about 8 blocks. My buddy doesn't even know why they towed it, they weren't in a no parking spot, but they got his car and two others for no good reason.

 

[nightspeed87]

damn i would be pissssed...

 

[Savage Talon]

Just 2 blocks will ruin the VC in your trans. I bet the VC is toasted.

 

[ChunkyLover53]

damn i would be pissssed...

I would also be pissed.

 

[TSG59_Steve]

Just 2 blocks will ruin the VC in your trans. I bet the VC is toasted.

Whats the VC? And if it is toast, would it make any noises or lock the tires?

 

[1g_tsi_awd]

Whats the VC? And if it is toast, would it make any noises or lock the tires?

Viscous coupler.

 

[TSG59_Steve]

Viscous coupler.

That's what I thought. Thanks.

How expensive is that?

 

[1g_tsi_awd]

There is one in the classifieds for 55. I am guessing new it would be 75+.

 

[DGajre777]

www.vfaq.com

"Why can't I tow an AWD [DSM]?
My AWD [DSM] was towed [at some time]! Did anything break?

You can tow an AWD DSM. The trick is to have all four wheels off the ground while it is being towed. This can be done using a flatbed tow truck, or putting the front wheels on dollies.

The reason that AWD DSMs should not be towed with two wheels on the ground is the limited-slip differential (LSD) which is present on many AWDs. The function of the LSD is (surprise!) to allow a limited amount of speed difference between the front and rear wheels.

[Please note that the operation of the LSD has been simplified here for the purposes of discussion. This is not a dissertation on the LSD itself.]

Under normal driving conditions, the front and rear axles rotate at the same speed. (This is what differentiates AWD from older 4WD vehicles - on 4WD vehicles, it is assumed that the front and rear wheels usually rotate at different speeds while the 4WD is engaged.) During this time, the LSD does no work, and is 'open', providing no coupling between the front and rear wheels of the car.

The LSD is a viscous (fluid-based) device, and contains no mechanical interlocks. When one set of wheels begins to slip, plates in the LSD rotate at different speeds. The speed difference creates friction, and therefore heat, in the LSD fluid. When enough heat is generated, the LSD fluid abruptly changes state from 'open' to 'closed' providing a semi-solid junction between the two plates. With the fluid now 'locked' the plates are forced to rotate at near-equal speeds, which is turn forces the axles to turn together. When the slip condition disappears, the LSD quickly loses heat and returns to an 'unlocked' state.

So, the raison d'etre of the LSD is to prevent excessive wheel slip between the front and rear axles. The only problem with this occurs if two wheels are forced to slip, while the other two remain stationary. This occurs, of course, if two wheels are on the ground (rolling) and two are stationary (lifted) while the car is being towed.

In this scenario, the LSD will quickly build up heat and 'lock', attempting to rotate both axles equally. Unfortunately, it is unable to do so, since the stationary axle is locked securely into place by the tow operator. The other option is to halt the rolling axle, but the LSD does not have the strength necessary to resist the force provided by a tow truck designed to pull much larger vehicles. So the LSD plates continue to slip, even when the LSD is 'locked'.

When placed into such an impossible situation, the LSD does the only thing it can do - build up heat until it self-destructs. The tow truck driver, driving a dually burdened with the added weight of a 3000 lb car, is unlikely to notice either the extra resistance provided by the LSD or the lack of resistance once the LSD burns out. By the time the car is again dropped to the ground, the LSD is literally toast.

This situation can easily be avoided by only towing the car with all 4 wheels off of the ground. The exact method used is not critical. And no, it isn't going to hurt the LSD to load the car - technically, the front and rear axles are never going to rotate at exactly the same speed during driving, so the LSD plates are always rotating at slightly different speeds. Obviously, this doesn't hurt it, since it runs in 'open' mode normally - the problems occur when it is 'locked' and still cannot equalize the axle speeds."

 

[lt1camaroman93]

Just to make sure, the VC that is toast is the on inside the trans?

 

[Savage Talon]

Yes it is located at the end of the trans near 5th gear. It is not all that hard to take out. Just pop off the end cover and you can see it.

 

[Mikes2Gen]

So im curious if i am reading correctly, if the wheels still turn and the LSD (VC) is on its way out is that the only piece that would be damaged from the tow?

 

[TSG59_Steve]

Keep this thread updated please. I would really like to know if this short tow damaged anything.

 

[HustlerTalon]

one way to find out is if your car transforms from AWD to RWD...then you know your lsd went out...that is what happend to my buddy's car when it was towed for like a mile by a dumb@$$ tow truck guy. RWD is fun! DRIFT!!!

 

[ilikespeeding]

Have a dealership check it out. They'll gladly do it, and the towing company will refund your money.

 

[Mr.Tao]

If you have the tools jack it up and test it. If not, take it to a dealer and they will inspect for free.

 

[VPrime]

My car was towed with the front wheels in the air, and back on the ground. I still had AWD in winter.. I am sure it put major stress on it but mine is not dead.
Also would the recall for the center yolk or what ever replace all parts that may have been damaged?
If so would be a nice way to get a "free" repair, but still get money from towing company and buy mods

 

[lt1camaroman93]

If you have the tools jack it up and test it. If not, take it to a dealer and they will inspect for free.

What is the proper way to test it? That's my main question cause I don't want to tear into his trans for no good reason if I don't have to.

 

[HustlerTalon]

jack up the car in the air and see if all the wheels turn on their own.

 

[1gcrazy]

jack up the car in the air and see if all the wheels turn on their own.

Then let us know what the hells up...

 

[lt1camaroman93]

Ok.... Car in the air... Turn one front wheel the other turns the opposite way but if I hold the other tire, there is next to no resistance and the other will still spin. If I turn the back slowly the other back will turn with some resistance. If I spin the back fast the fronts will slowly move a little bit.