Keep stirrin'

[blacksnapon]

A front wheel drive vehicle pulls hard whenever power is applied.It only does it while accellerating. Technician A says unequal length driveshafts can cause it.........Technician B says its caused by mis-adjusted rear brakes. Who's right? Technician A.........Technician B...........Both...........neither

 

[O'Rattlecan]

you got me. I'll guess though! I vote for driveshaft man. Sounds better than a brake grabbing for no reason only under acceleration.

Ryan

 

[Blue Goose]

Vince, is this the same symptom known as torque steer?

 

[Skandocious]

Different length driveshafts front to rear? Why would that have anything to do with this... Are we talking about seeing the problem in 2wd or 4wd...? Even so, why would it matter? My driveshafts are different lengths, I would imagine most trucks have different length driveshafts front to back.

My bet would be a bad wheel bearing or maybe a break problem like you mentioned.

 

[Blue Goose]

Chris, re-read the first sentence of Vince's post...

 

[blacksnapon]

Different length driveshafts front to rear? Why would that have anything to do with this... Are we talking about seeing the problem in 2wd or 4wd...? Even so, why would it matter? My driveshafts are different lengths, I would imagine most trucks have different length driveshafts front to back.

My bet would be a bad wheel bearing or maybe a break problem like you mentioned.

Remember, front wheel drive!

 

[Skandocious]

Hmph. I'm not very well versed with the way a front wheel drive car works... Don't they usually have a transaxle instead of driveshafts? If that's the case, I'd think it'd be a problem in that transaxle, maybe allowing some slipage on one axle shaft... That's a complete guess, I have no clue how they work.

 

[polarbear]

Technician A. There's power loss that increases with the length of the driveshaft.

 

[blackhat620]

Tech A is correct, it is do to torque steer caused by the unequal drive shaft length between the front wheels. Generally the wheel served by the longer drive shaft has more power loss do to the increased shaft twist or wrap up. Since the wheel served by the shorter shaft receives its power sooner do to less drive shaft twist, you get torque steer or pulling.

 

[Skandocious]

Why would you have different shaft lengths? I mean... How could that happen unless it was that way from the factory? A shaft can't suddenly become shorter...

 

[polarbear]

A number of manufacturers (like *cough cough* GM) have used unequal length shafts for years because of packaging under the hood. I remember the old Sunbird turbo's that would literally leave the road when you punched the gas unless you were hanging onto the steering wheel tightly with both hands.

 

[lil_dq]

defiantly A had a neon that did the same thing and it was because the transmission was on the driverside of the car so it got more torque than the longer pass side shaft!

 

[blackhat620]

Why would you have different shaft lengths? I mean... How could that happen unless it was that way from the factory? A shaft can't suddenly become shorter...

They come that way from the factory, just about all FWD cars the drive (axle) shafts are different lengths, this causes torque steer under acceleration, no different than you get by putting a locker or spool in the front axle of a Jeep (front differential on a 4WD is off center resulting in different length axle shafts). The engineers try and use other components in the FWD drive shaft setup to reduce the feel of torque steer but it is difficult to completely eliminate. Look under the front of any FWD car and you will see that generally the right wheel drive shaft is longer than the left wheel drive shaft. The longer drive shaft will twist or wrap-up more than the left shaft causing power loss (do to the twisting) resulting in the left wheel turning faster than the right wheel, this causes the vehicle to pull do to the torque steer effect.

 

[6L PWR]

Tire pressure being off can make it worse. Again, a bit of experience speaking.

 

[BudDog]

Technician A.

 

[1970Custom]

I hate torque steer, try it with bad CVs on the long axle.

Buddy of mine has a stage II SRT4 Neon that is flat freaky when hitting the skinny pedal.

 

[surewhynot]

Tire pressure being off can make it worse. Again, a bit of experience speaking.

I wonder, could you play with tire pressure to minimize it. Not for evryday driving, but lets say on a dragstrip.

 

[6L PWR]

I wonder, could you play with tire pressure to minimize it. Not for evryday driving, but lets say on a dragstrip.

Don't know. I haven't got that car anymore and I wasn't smart enough back then to think of that.

 

[mrfixit]

Neither. The condition is caused by the fact that FWD "differentials" or Transaxles are FLUID drive, or Non-direct/non locker. This is what keeps tires from tearing up in turns, as it allows one wheel to travel faster than the other following the arc of a turn; In applying power, one wheel is going to try to pull harder than the other. In RWD vehicles, this is what gave us those wonderful burnouts on non-modified cars. (I still recall how my family boat had one rear tire constantly more worn than the other, lol)

It's POSSIBLE the length of the axle shafts are what determines WHICH side it pulls to, as longer shafts mean weaker torque, but it's still because of the differential.

 

[blacksnapon]

Its tech "A" Unequal length driveshafts have been an issue for a while. It was real noticeable with the early chrysler products. The manufacturers started putting in a "Carrier bearing" in the right side.