Torque Steer after replacing Driveshaft?!!!

[Super-DA9]

Hi everyone, yes, another issue... *sigh*

yesterday I changed my left CV shaft in my DC2 for a brand new protex one, and everything went well, except now the car is torque steering to the left. not heavily or anything, but in 1st, 2nd, 3rd gears when you let go of the steering wheel even for a few seconds under about 50% acceleration the steering wheel just turns left by itself, and under heavy acceleration in 1st and 2nd you can feel the steering wheel pulling against your hand a bit. and it's always left! never turns right by itself.

when I'm in a straight line under no acceleration, or when I'm braking it seems to be pretty much straight, but when it's under acceleration it wants to turn left.

I'm pretty damn certain I did EVERYTHING right when replacing the CV shaft (it was the first time I've attempted it though) and I got a wheel alignment today but still torque steering.

I know it's normal to get a bit of torque steer in FWD's like this, but I'm pretty certain it wasn't like this before I changed the driveshaft.

The job card they gave me after the wheel alignment said that my front camber was 1.1º negative on the left and 0.9º negative on the right, this is most likely because it's on N+ coilovers and the difference in left/right camber is so minor it shouldn't matter right?

Car is equipped with:
BuddyClub N+
Xforce 4-2-1 Headers, High flow cat, 2.25" Cat-back
17" Wheels

But bare in mind this has only seemed to happen after putting in the new CV shaft!

I know it's not really bad torque steer so it's not a massive problem, but it's bugging me.

Please Help?

[newpaddy3]

Torque steer is when there is an unequal length and weight of the drivesharts.

How much of a weight difference is there between the Protex brand and the one you replaced?

[Super-DA9]

oh jeez good question... there's no weight listing but it is the right one for the car. would replacing the other side with one of the same brand fix this?

[Vvvtec]

oh jeez good question... there's no weight listing but it is the right one for the car. would replacing the other side with one of the same brand fix this?

How much did that set you back? If it is a relatively cheap part, I'd suggest you change it, even if just for piece of mind?

I know in my car I generally have a tad bit of torque steer, but it's barely noticeable.

I understand your concern though, especially as it has only just started happening. Best bet would be just to replace your right hand side drive shaft with one as the same on the left, then let us know if that solves the problem :)

[string]

Torque steer is when there is an unequal length and weight of the drivesharts.


Nonsense; besides, DC2 driveshafts are symmetrical left and right.

Longitudinal forces at the contact patch cause a torque around the steering axis. The distance of this lever arm is called the scrub radius. This results in a force on the tie-rod. In a perfect world, both tyres will receive the same drive force and will return equal and opposite forces to the steering rack summing to zero.

In the real world, drive torque isn't always equal to each tyre and the scrub radius is certainly not equal after 10 years of bushing abuse.

[Super-DA9]

In the real world, drive torque isn't always equal to each tyre and the scrub radius is certainly not equal after 10 years of bushing abuse.

even so, the fact that it only just started happening after changing the CV shaft suggests that it might be to do with the CV shaft.. :(

[string]

even so, the fact that it only just started happening after changing the CV shaft suggests that it might be to do with the CV shaft.. :(

Or you didn't re-assemble everything in an identical fashion. Every millimetre counts.

[Super-DA9]

yeah i agree, every little bit counts. but i made sure i put everything back together right, i triple checked everything before lowering the car back onto the ground, and if there was something i had out of alignment they would have fixed it in the wheel alignment today. which is why it's a bit confusing...

[Lukey]

if it isnt to costly, id replace the right one aswell like others have suggested.


Nonsense; besides, DC2 driveshafts are symmetrical left and right.

Longitudinal forces at the contact patch cause a torque around the steering axis. The distance of this lever arm is called the scrub radius. This results in a force on the tie-rod. In a perfect world, both tyres will receive the same drive force and will return equal and opposite forces to the steering rack summing to zero.

In the real world, drive torque isn't always equal to each tyre and the scrub radius is certainly not equal after 10 years of bushing abuse.

afaik the lhs has an intermediate shaft before the inner cv joint, which would make it torque steer slightly to the left regardless.

[string]

afaik the lhs has an intermediate shaft before the inner cv joint, which would make it torque steer slightly to the left regardless.

Why?

And don't give me some rubbish about it "winding up" like all the other bullshit websites on the internet.

Not attacking, I just don't buy the myth that gets repeated over and over and over.

[string]

yeah i agree, every little bit counts. but i made sure i put everything back together right, i triple checked everything before lowering the car back onto the ground, and if there was something i had out of alignment they would have fixed it in the wheel alignment today. which is why it's a bit confusing...

The only thing they do in a wheel alignment is adjust the tie-rods. Take the inner LCA bushing as an example. The bolt which goes through the sleeve has a little bit of wiggle room. That wiggle room can make all the difference (exaggeration alert) and an alignment will do jack shit to fix it.

Symmetrical static alignment specs is one thing but in no way implies exactly symmetrical geometry.


When did you tighten the bushings? Full droop? Ride height? Half-way?

[Lukey]

Why?

And don't give me some rubbish about it "winding up" like all the other bullshit websites on the internet.

fwd's will always torque steer to the side which has a longer shaft?

and what do you mean 'winding up'??

[string]

fwd's will always torque steer to the side which has a longer shaft?

and what do you mean 'winding up'??

The usual claim is that a longer driveshaft "flexes" somehow contributing to different torque at the tyre.

If there were any truth to this, then, like a spring, it will reach maximum deflection after a given ammount of time and then remain deflected until the torque is removed. The time constant of an imbalance caused by this mechanism would be TINY.

[Lukey]

ahk. but ive noticed my dc4 also torque steers to the left a bit.

thats what i was taught in tradeschool, that the car will torque steer to the side with the longer drive shafts, even if they are the same lengths, but with the intermediate shaft (i hope that made sense to you?)

[newpaddy3]

I was of the belief that it was due to inertia

[string]

I was of the belief that it was due to inertia

An open differential will apply 50/50 torque. If one side has a greater rotational mass then indeed the tyre will see less of the torque.

Unfortunately for such an argument, the radius of the driveshaft is about 0.5cm so the moment of inertia would be microscopic relative to the wheel and tyre. Then consider that we are only interested in the DIFFERENCE between the moments of inertia of the two driveshafts. I doubt such a difference would consume even a millionth of the mechanical energy.

[Lukey]

this conversation has gotten way out of my vocabulary. i shall now exit the thread.

[string]

The OP already indicates a left/right suspension imbalance. Old bushings don't like to be mucked with. The rubber developes a memory and likes to keep deforming the same way so it's critical to keep them happy, otherwise they will deform or tear and further throw out your L/R balance which is where torque steer thrives.

The mechanism for torque steer is identical to that of steering pull under braking. Scrub radius or longitidinal force - if they're not equal left/right, it's going to pull.

[newpaddy3]

So in layman's terms how is torque steer generated?

[Lukey]

yea not everyone is intelligent like you. lol

im a dumbshit

[newpaddy3]

lol you're not dumb Lukey, just not accustomed to the wording

[Lukey]

i look at his sentences and im like :confused::confused::confused::confused:

haha

[newpaddy3]

haha yeah I'm lost at scrub radius and longitidinal force and how they equate with it all.

[chauster]

Just get LSD. k

[newpaddy3]

Doesn't stop torque steer, only alleviates it.

[Super-DA9]

ok so, I'm going to call protex tomorrow and ask for the details on the weight of the part, and I'll weigh the old one, and if there's a significant difference, I'll order a RHS one. If it's is the same or too close to have an effect, I'll order new bushings, probably go suspension bushings all round. I can replace these myself, however I'll have to have everything aligned correctly afterwards... *sigh*

so if a wheel alignment is just adjusting the tie rods... (even though on the job card they gave me it shows toe in, camber etc. not sure what the go is there)

then what do I ask for to get everything adjusted/aligned correctly..?

:S

[Vvvtec]

ok so, I'm going to call protex tomorrow and ask for the details on the weight of the part, and I'll weigh the old one, and if there's a significant difference, I'll order a RHS one. If it's is the same or too close to have an effect, I'll order new bushings, probably go suspension bushings all round. I can replace these myself, however I'll have to have everything aligned correctly afterwards... *sigh*

so if a wheel alignment is just adjusting the tie rods... (even though on the job card they gave me it shows toe in, camber etc. not sure what the go is there)

then what do I ask for to get everything adjusted/aligned correctly..?

:S

I'm actually quiet interested in seeing if there is a difference between the OEM product and the one you have just installed, although there really shouldn't be.

Replacing other things like bushings is probably a good idea anyway, like someone mentioned before bushings and the like develop a 'wear memory' overtime (common sense I know I'm sorry). PLUS, if you are going to get everything realigned again, you may aswell just take the opportunity to fiddle around and replace them before you do go get it aligned.

If you look at the positives, you will potentially come out of this with
-Brand spanking new driveshafts
-New bushings
-A good wheel-alignment
And most importantly a whole heap of experience on the issue!

Good luck bro, remember to tell us if there is a difference between the OEM/aftermarket product!

[string]

Super-DA9: can you answer my question in bold?


Just get LSD. k

Will make the problem worse. An open diff wants to give both wheels half the torque - an LSD such as a torsen is quite happy to support an imbalance which will lead to torque steer even with perfect suspension geometry.



so if a wheel alignment is just adjusting the tie rods... (even though on the job card they gave me it shows toe in, camber etc. not sure what the go is there)

then what do I ask for to get everything adjusted/aligned correctly..?

:S

They measure all the angles and give them to you in a printout, but the only thing that the $50 places adjust is toe. If you want to do it properly you need to adjust all the suspension points and the subframe. I don't know anywhere which does this but I'm sure it exists somewhere (there'd be lots of $$ involved).

[Super-DA9]

I tightened the bolts (of which went through the bushes, in the areas that I had to play with anyway) when the car was on stands at the front with the wheel off. I think I see what you're getting at, maybe I tightened it more than the other side..? or possibly did it at the wrong time?

Ah ok, so I need to actually ask for everything to be adjusted. In that case I think I'll purchase a full front set of bushes and install them, and then get everything aligned correctly. The bushes in there look pretty old lol.

In terms of different driveshaft weights, I called up the company today, and the foreign lady I spoke to had NO F**KING IDEA what I was asking about... but I also contacted honda and they said that driveshafts need a little bit of time to "wear in" properly, and to wait a bit.

I'll keep ya'll updated, thanks for the suggestions so far everyone. :)

[string]

If you tore one of your old bushings, you might have some wheel movement when you get on the power.

[Super-DA9]

yeah that could be it, I'm still trying to hunt down a full front set of bushings, or a full car set that doesn't cost an arm and a leg. thank you for your advice, I'll let you know how it goes after I get it done.