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I’m hoping for some good advice here…I’m a longtime DIY car repair guy, and also have been watching ETCG for a few years which has been so helpful!
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.
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You may need a front end alignment. Here are some other things to check.
Sure, good thought. I actually had the front end aligned when the lower control arms were done, and the issue didn’t clear. None of the items mentioned in the article you linked really seem to match up with my issue…I definitely have things inflated appropriately, and I don’t think what I have is excessive play in the steering wheel.
As best I can tell and remember, there wasn’t a repair which triggered it. It began gradually in the Fall of 2015 and for the first several month I thought I was just imagining it until it became more and more noticeable. I only put 7 or 8k miles on this car per year as it’s now our in-town daily driver, so the issue has only been really noticeable for 5 or 6k miles. The way it began gradually and worsened over time makes me think of something becoming worn being the cause.
Are the rims upgraded and what are the road conditions like where it happens?
Under heavy acceleration, a FWD car will torque-steer. It’s the nature of having unequal length drive shafts.
I’d still be looking at suspension play, front ball joints and steering linkages first, possibly in the rear even.
The rims aren’t upgraded, and it happens on any kind of paved road, whether it be rough, badly patched asphalt or nice, smooth, freshly paved asphalt.
I understand a certain amount of torque steer is normal, but as I said, this is something which has worsened over time – it went from not being there to being a little bit there to being more and more noticeable. Thus, it feels like something is wearing out, causing it to become worse. The MPV is equipped with an intermediate drive shaft so as to cause the CV axles to be close to the same length on each side, which, as I understand it, should reduce torque steer.
As an aside, I also have a 2006 Mazda MPV; the ’06 is equipped with a 3.0L V6 and a 5-speed auto transy, but the steering and suspension, even the drivetrain from the transy out to the wheels, is basically identical, and it doesn’t have this problem. It also has 50k fewer miles. And it doesn’t exhibit even a hint of torque steer.
The ball joints are brand new, as they came already pressed into the new lower control arms. The mechanic who did that work swore the tie rods and rack and pinion were tight…guess I should get a second opinion on those.
Well, I jacked up the front end and started looking for play. I found play on the passenger wheel, hunted around, and found that there was movement at the balljoint where it goes into the knuckle. So, I took off the wheel and got my 14mm sockets and tightened it back up. This got rid of the play but unfortunately didn’t get rid of the root problem.
I’m wondering if perhaps the torque steer is exerting forces on that balljoint and knuckle causing it to loosen up.
I pushed and pulled on the tie rods and found no movement in them as well.
Then I jacked up the back end and looked for play at the rear wheels. Found no play there, everything felt nice and tight.
[quote=”clewis” post=180687]Well, I jacked up the front end and started looking for play. I found play on the passenger wheel, hunted around, and found that there was movement at the balljoint where it goes into the knuckle. So, I took off the wheel and got my 14mm sockets and tightened it back up. This got rid of the play but unfortunately didn’t get rid of the root problem.
I’m wondering if perhaps the torque steer is exerting forces on that balljoint and knuckle causing it to loosen up.
I pushed and pulled on the tie rods and found no movement in them as well.
Then I jacked up the back end and looked for play at the rear wheels. Found no play there, everything felt nice and tight.[/quote]
No cotter pin in the castle nut?
The ball joint on the lower control arm on the MPV doesn’t use a castle nut. Instead, the shaft of the ball joint goes into a hole in the bottom of knuckle. The shaft of the ball joint has an indentation in it, and a bolt goes through the knuckle perpendicular to the ball joint’s shaft. A nut screws onto the bolt on the other side, and that bolt basically sits against that indentation in the ball joint shaft, holding it steady.
So there’s no castle nut or cotter pin involved. There is a castle nut and cotter pin on the tie rod ends though.
Here’s a video that lays out how the LCA and balljoint are set up on the MPV. If you jump ahead to 0:45 then you’ll see how the ball joint is set up with its bolt.
This just keeps getting stranger. On Saturday afternoon I found that play in the passenger side which I found to be happening at the ball joint’s connection to the knuckle, so I tightened it up. The play was gone. I made one short trip Saturday afternoon, and then a longer trip on Monday. Things felt decidedly better. The most obvious thing was that while the torque steer was still present, the noticeable twitch when the steering wheel jerked back to straight was gone. It was a very gentle return to straight once I let off the gas. Then yesterday and today, it’s back. Last evening I jacked up the front passenger side and noticed the play is back. As soon as I get a chance I will tighten it up again, but that leaves me wondering – why would this be loosening up all by itself with only 20-30 miles of driving? Could the brand new balljoint be the problem? Could the bolt be worn out? Could the hole in the knuckle the balljoint fits into be reamed out? Could it be as simple as a missing lock washer or something?
The bolt should have a shoulder to lock the up/down direction, if its fully threaded the thread will get smashed and you’ll have play. (mostly up/down).
The nut should be a nylock, to prevent it from coming loose.
And make sure its tight / torqued to spec, as the bolt/nut also applies clamping force, which is whats stopping the whole thing from having play. When in doubt, just make it a little tighter.
If the new ball joint is somehow the wrong diameter, that could probably cause issues, but its not something I’ve seen so far.
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