Torque steer issue on 2001 MPV
 

The car is the 2001 Mazda MPV with the 2.5L and 4-speed auto. 175k miles, with 100k of those being mine over the last 9 years.

The symptom is, when starting from a stop, as we go up through first and second gear, the steering wheel pulls 30 degrees or so to the right. When we ease up on the accelerator, and the trans shifts up into 3rd, the steering wheel straightens out and the ride is great. During low speed acceleration, with the wheel pulling to the right, the car pretty much drives straight; if I hold the steering wheel straight during this, then the car drives off to the left (not a hard left, just like a lane-change to the left.)

I'm normally a DIY guy and the MPVClub has been invaluable to me, but no one over there seems to know what to do so I figured I would post here.

The first thing I did was swap the front tires to see if the uneven wear on them was contributing to the issue. This didn't change anything. Next I went to a mechanic who noticed the passenger ball joint was shot; so, I had both lower control arms replaced as the passenger LCA bushings were shot as well.

This repair didn't resolve the issue.

Mechanic also pointed out to me that the motor mounts were pretty worn, especially the passenger upper mount. I replaced the lower front mount a bit over a year ago, so I went ahead and replaced the (very worn) passenger upper mount, but the issue remained. My mechanic noticed my struts were frozen, so I replaced both of them myself. Ride handling improved but the issue remains.

I then went to another reputable mechanic in town and had them drive it. They said, it feels like a transy problem, and sent me to the transy shop. The guy from the transy shop test drove it and came back and said it felt to him like a steering/suspension issue and definitely not a transy issue. So then, I went to a 3rd reputable mechanic who test drove it with me and unequivocally pointed to the engine mounts. Said the whole engine and transy were shifting in the engine compartment when at high torque and low speed, and this was shifting the whole drivetrain, hence the pull to the right. So, I replaced driver upper mount (really a transy mount.) Replacing these two mounts definitely reduced the amount of movement of the engine and transy in the engine compartment, but the issue remains. Attempted to replace the lower rear mount myself, couldn't get it done so paid my mechanic to do it (he said it killed about half his day, as it's quite difficult to replace.) Aaaaand the issue remains.

That brings us up to yesterday afternoon. A few things to note:

1. When he replaced the lower control arms, my mechanic and his helper pushed and pulled and yanked and twisted and couldn't find any looseness in the tied rod ends, the rack and pinion, anything at all. They swear the front end is tight.
2. Shifting is as smooth as can be, and once you're in 3rd gear and higher, you can cruise straight as an arrow down the road without vibration in the steering or anything like that.
3. If I'm doing 30mph or so and punch the gas to cause a downshift, then the steering wheel pulls to the right; as soon as I let off the gas the steering wheel straightens right back out. Therefore I am disinclined to think this is a brake issue.
4. The whole van (understandably) twitches when the steering wheel straightens out as torque decreases on the upshift.

This whole thing at this point, with steering and suspension nice and tight, feels a lot like at low speed and high torque, more torque is being delivered to the left wheel than the right, causing a torque steer to the right.

What should I be checking? This is the only thing wrong with this van, and while it isn't worth much with this much mileage and 15 years of age, I'd like to fix it and drive it a while longer. Realistically, I probably wouldn't pay to rebuild the transy, but if there were something in the differential or elsewhere in the drivetrain to check, I would be up for that.

Right front wheel bearing.

When you increase wheel torque they try to increase toe-in under the engine power. The car goes straight but the wheel turns some to the right so it IS firmly linked to the left wheel but something moves on the right side. Stuff that holds the wheel in alignment is wheel bearing, steering rack/arms/links/joints, lower track control arm.

From what you have said only the wheel bearing hasn't been ruled out. But the issue IS one of losing front wheel alignment under power and that means the issue is on the right side of the car. It might explain uneven tire wear too depending on the pattern.

Interesting idea. I had the driver front wheel bearing done 2 years ago - the symptom was, it was noisy - made a grinding noise. And, when off the ground, there was a tiny bit of play in it. When the shop replaced it they found the hub assembly to be rounded out - so they replaced both the bearing and the hub assembly. I don't have noise from the passenger side or play from top to bottom...

Which brings me to my latest update. Saturday I jacked the front end up and looked for play myself with the steering wheel unlocked. Wanted to see if I could get any movement out of one wheel before the other one started moving...started with the driver side, and found that as soon as the driver wheel started steering one way or the other, the passenger wheel started moving too. Went over to the passenger side, and found a small, but noticeable amount of movement before the driver wheel started moving. Positioned myself where I could look at the inside of the wheel, hub, tie rod area, etc...I could see the movement was primarily in the strut, not in the tie rod...kept wiggling it, found, finally, movement at the ball joint where it goes into the knuckle!

Kind of stinks since I just had that control arm and ball joint replaced. So, I took off the wheel and removed the bolt that retains the ball joint in the knuckle. Didn't see anything obviously strange about it, so I put it back in and tightened it up pretty hard. Went out and drove and had a noticeable improvement (before dropping the front end I confirmed that movement I had noticed was gone in the passenger side.

Drove it for 2 days, all of 40 miles, and it was feeling pretty much like it did before I tightened it up. Just now I have tightened it again. This time I took the bolt out and examined it pretty closely. I noticed it has a pretty worn looking flat spot on it, where the ball joint's shaft rubbed it for the first 175k miles or so. This time, I reinstalled it and deliberately had it turned where the flat spot was away from the ball joint shaft. I'm starting to think maybe it's working its way around to the flat spot, and the flat spot allows the ball joint too much movement in the knuckle...

Torque steer similar problem. has there been a resolution ?
 

Hello my name is Scott. I have a 2000 MPV minivan and while driving the van at any speed if you accelerate the vehicle will go to the left in oncoming traffic and when you decelerate is letting off the gas then vehicle will go to the right towards the ditch so anytime the vehicle will shift it will move the van with the driver holding the steering wheel straight. In a small panic the driver has to counter steer the van back. steering also to the right when it up shifts into the left when it down shifts so if you put the vehicle in Low 1 and give it gas it's going to jump to the right and when you let go jump to the left you can do that all day long at whatever speed you want.
please help me with any resolutions or anything that I can try I am going to check the motor mounts it's hard to see the engine when you are sitting in the driver seat but I did not feel any movement from the engine jumping around everything runs smooth when I was sitting in it and testing engine moment.
my guess is its something wrong in the transmission ????
But it seems like torque steer ?
Well plerse help if you can :)
Thank you
Scott.

Its not torque steer or motor mounts, you have a ball joint with some play in it in the front suspension, if the car moved right under power then the play will be in the left suspension.

Jack up the appropriat side and use a lever on the suspension and steering joints, usually you will be able to find/feel the joint with the play in it fairly easily

Simonsi - you are correct - I ended up getting a new nut and bolt and torquing it by hand as hard as I could - and the issue resolved for a few days. Then I took it to my tire shop and had them check it out - they found the same issue with the passenger ball joint which I had found and they tightened it up using their impact gun...it drove perfectly for 2 weeks and then just on Friday it loosened up again. It is not bad yet, just a bit noticeable. I'm thinking I need to replace the whole knuckle since the hole the ball joint shaft goes into is apparently not holding the ball joint tightly in spite of tightening the nut and bolt up a lot.

Haunted, torque steer usually pulls to the right under high torque, not left. It sounds to me more like you have looseness in your steering somewhere. Jack up both sides of the front end and look for play by pushing and pulling one wheel - is there movement in your driver side wheel before the passenger wheel starts moving? Test it from the passenger side also. My guess is you'll find movement disparate between the two wheels - this could be caused by work tie rod ends, inner tie rods, or worst case, the steering rack itself. However, you should also check out your ball joints and lower control arm bushings as they could be worn out as well. Any of the above could contribute to unwanted/unexpected movement when holding the steering wheel still.