Pulling to right under acceleration
Discussion
Afternoon all,
I posted this in the "MX5" section but its pretty quiet, I thought I may get more of a response in here seeing as its a specific suspension section.
My missus was complaining that her 2017 MX5 "didn't feel right." I noticed that the steering wheel was left hand down when going in a straight line. Recent possible relevant history is that before Christmas her rear nearside tyre was loosing pressure, this was due to a dent in the rim on the inside caused by a pothole (it had also pinched the tyre sidewall). I had a new tyre fitted, and then got the rim "straightened" at another place the tyre fitters recommended.
Today I had the alignment checked and the front toe was out on the offside (-0.04 degrees compared to +0.04 degrees on nearside front), everything else was pretty much within spec. Toe adjusted and off I went but found steering still left land down going straight ahead. I went back and they rechecked/adjusted twice more (with them test driving each time) and reported that the wheel was now straight. On way home everything seemed fine until I got onto faster roads.
Under acceleration, the car pulls slightly to the right which requires turning to the left very slightly to compensate. When I back off the throttle, the car then veers to the left and you need to turn the wheel back to straight ahead. Its is very unerving, it feels like the front/back axles are working against each other. This only manifests under reasonable acceleration. If I am poodling along at a constant speed then there is no issue, but as soon as the accelerator is pressed with any sort of vigor the problem appears. It is much more apparent at higher speeds (60/70ish).
In my mind, something is allowing movement under load which should actually be fixed/rigid if that makes sense? Assuming the geometry of the car when static is indeed correct (I've used this garage for some time and they have a very good reputation), then I assume it is going out of alignment under load (acceleration) because something that should be fixed is actually moving (ball joint/bush etc)? Or could it somehow be a tyre or alloy issue? My gut feeling is it isn't, because the problem only shows under acceleration.
I would be grateful for any help or suggestions, or recommendations for a decent MX5 specific forum to ask for help on, or a decent MX5 specialist garage ideally in the North Essex area.
Many thanks
Here is a pic of the geometry prin out after alignment:
I posted this in the "MX5" section but its pretty quiet, I thought I may get more of a response in here seeing as its a specific suspension section.
My missus was complaining that her 2017 MX5 "didn't feel right." I noticed that the steering wheel was left hand down when going in a straight line. Recent possible relevant history is that before Christmas her rear nearside tyre was loosing pressure, this was due to a dent in the rim on the inside caused by a pothole (it had also pinched the tyre sidewall). I had a new tyre fitted, and then got the rim "straightened" at another place the tyre fitters recommended.
Today I had the alignment checked and the front toe was out on the offside (-0.04 degrees compared to +0.04 degrees on nearside front), everything else was pretty much within spec. Toe adjusted and off I went but found steering still left land down going straight ahead. I went back and they rechecked/adjusted twice more (with them test driving each time) and reported that the wheel was now straight. On way home everything seemed fine until I got onto faster roads.
Under acceleration, the car pulls slightly to the right which requires turning to the left very slightly to compensate. When I back off the throttle, the car then veers to the left and you need to turn the wheel back to straight ahead. Its is very unerving, it feels like the front/back axles are working against each other. This only manifests under reasonable acceleration. If I am poodling along at a constant speed then there is no issue, but as soon as the accelerator is pressed with any sort of vigor the problem appears. It is much more apparent at higher speeds (60/70ish).
In my mind, something is allowing movement under load which should actually be fixed/rigid if that makes sense? Assuming the geometry of the car when static is indeed correct (I've used this garage for some time and they have a very good reputation), then I assume it is going out of alignment under load (acceleration) because something that should be fixed is actually moving (ball joint/bush etc)? Or could it somehow be a tyre or alloy issue? My gut feeling is it isn't, because the problem only shows under acceleration.
I would be grateful for any help or suggestions, or recommendations for a decent MX5 specific forum to ask for help on, or a decent MX5 specialist garage ideally in the North Essex area.
Many thanks
Here is a pic of the geometry prin out after alignment:
Do the tyres match across the axle? I’ve had a hire car with mismatching ditch finders across an axle, one tyre had more grip than the other and it torque steered with anything more than a medium throttle opening, pulling towards the tyre with less grip.
Also where did you get that alignment done? Although my regular car drove normally, I had ‘free’ alignment check at a tyre fitting place which showed red everywhere. £90 later, I had an all green print out, but the car wouldn’t drive straight anymore. It was totally fine before the ‘alignment’ on a Hunter Laser machine. Long story short, I had to take it to a marque specialist who returned it back to its normal state. Will never get an alignment done at a tyre fitting place again.
Also where did you get that alignment done? Although my regular car drove normally, I had ‘free’ alignment check at a tyre fitting place which showed red everywhere. £90 later, I had an all green print out, but the car wouldn’t drive straight anymore. It was totally fine before the ‘alignment’ on a Hunter Laser machine. Long story short, I had to take it to a marque specialist who returned it back to its normal state. Will never get an alignment done at a tyre fitting place again.
Edited by wyson on Thursday 11th January 09:49
wyson said:
Do the tyres match across the axle?
Thank you for replying.They are identical across both axel's, the exact same tyre on each corner. I've also made sure the pressure's are spot on.
However, you've got me thinking and I've just been out to check something. The nearside rear tyre was replaced as mentioned in my post above so is brand new. I've looked at the offside rear and the tread is approx 2mm off from reaching the wear markers. Could this difference in tread depth (which would cause an, albeit miniscule, difference in tyre circumference) cause the issues I'm having? Or would the LSD cancel out any issues caused by running a brand new and worn tyre on that axle? It's a RWD car after all?
Edited by Toilet Duck on Wednesday 10th January 18:22
wyson said:
Also where did you get that alignment done? Although my regular car drove normally, I had ‘free’ alignment check at a tyre fitting place which showed red everywhere. £90 later, I had an all green print out, but the car wouldn’t drive straight anymore. It was totally fine before the ‘alignment’ on a Hunter Laser machine. Long story short, I had to take it to a marque specialist who returned it back to its normal state. Will never get an alignment done at a tyre fitting place again.
I'd rather not name the company, but the initial print out did tally up with the left hand down whilst steering straight symptom. Obviously the magic Hunter equipment is only as good as the person using it, but these guys are well respected. It's an independent place, not part of a chain. They have set my Ariel Atom alignment up before and I'm mega fussy who works on that. Obviously I cannot be 100% certain, but I do not think the issue is with the alignment place.wyson,
A pothole big enough to damage a tyre may have damaged the steering links. Does a steering geometry check include a careful check of the linkage?
A start might be DiYable, front up on stands, good torch and prybar, go right through it for bends and looseness.
Good luck especially in the present weather!
John
A pothole big enough to damage a tyre may have damaged the steering links. Does a steering geometry check include a careful check of the linkage?
A start might be DiYable, front up on stands, good torch and prybar, go right through it for bends and looseness.
Good luck especially in the present weather!
John
tapkaJohnD said:
wyson,
A pothole big enough to damage a tyre may have damaged the steering links. Does a steering geometry check include a careful check of the linkage?
A start might be DiYable, front up on stands, good torch and prybar, go right through it for bends and looseness.
Good luck especially in the present weather!
John
Hiya,A pothole big enough to damage a tyre may have damaged the steering links. Does a steering geometry check include a careful check of the linkage?
A start might be DiYable, front up on stands, good torch and prybar, go right through it for bends and looseness.
Good luck especially in the present weather!
John
After she hit the pothole I did jack the car up and had a good look around. I also used a prybar to see if there was any flex/movement in any of the linkages etc. At this point the car was not pulling under acceleration, it was just needing left hand down to keep it driving straight. The tyre started loosing pressure so every week or so I put some air in it. When I finally got round to having it checked that's when I had the alloy straightened and new tyre fitted. It seems to be from this point that the pulling under acceleration started. I don't often drive the car so I can't be 100% certain, I'm relying on my missus telling me. She didn't actually specifically realise it was pulling under acceleration, just that it didn't feel right and didn't inspire confidence. I can't see how straightening a wheel can cause this pulling? So I'm starting to think it's due to a brand new tyre on nearside rear and an old/partly worn tyre on the offside.
I think I'll try swapping the wheels from front to rear (assuming front tyres have even wear which I believe they do) to see if the issue stops. If it does, then it will be getting a new tyre on the offside rear.
I doubt an MX5 has got enough grunt for a minor tyre difference to upset things. It sounds as though something's got bent or broken under there.
I'd start by getting her to drive the car while you drive behind, and see if the back's actually following the front under various conditions, i.e. acceleration, steady straight line and braking. If a car or motorcycle is "crabbing" it's often very obvious from behind.
I'd start by getting her to drive the car while you drive behind, and see if the back's actually following the front under various conditions, i.e. acceleration, steady straight line and braking. If a car or motorcycle is "crabbing" it's often very obvious from behind.
@toilet duck your suspicion about the differing tyre circumference between the nearly worn tyre and the new tyre on the same axle is exactly what caused this situation for me, and replacing the worn tyre for a new one matching the other side cured the handling issue.
In my experience my mx5 is very susceptible to differences in tyre circumference.
The silver lining is that you're only 2mm away from the wear indicator on the worn tyre anyway.
In my experience my mx5 is very susceptible to differences in tyre circumference.
The silver lining is that you're only 2mm away from the wear indicator on the worn tyre anyway.
Update as promised.
I took both rear wheels off today and checked all bushes etc with a prybar, I can't find anything wrong unless I'm somehow missing something. None of the bushes had any play.
I swapped the rear wheels to the front and took the car out. It's very subjective and the roads are crap, but it still does not feel right under acceleration. If anything, I'm reasonably sure it now feels like it's pulling to the left under acceleration which makes no sense to me (it was originally pulling to the right under acceleration).
The wheels from the front which are now on the back have tyres with equal tread. The nearside front wheel now has the brand new tyre.
Could unevenly worn fron tyres cause "pulling" under acceleration? I can't see how as it's RWD?
I have not checked front bushes (in hindsight this was a stupid mistake) as I was convinced the problem is at the rear.
I'm still trying to find an MX5 specialist or company that sets up track/race cars to double check wheel alignment. It's not a track car but those sort of outfits usually spend as much time as needed making adjustments.
I think I am going to get a new tyre fitted and swap the wheels back front/rear, so I have two new tyres across the rear axle.
Thanks again for everyone's help so far
I took both rear wheels off today and checked all bushes etc with a prybar, I can't find anything wrong unless I'm somehow missing something. None of the bushes had any play.
I swapped the rear wheels to the front and took the car out. It's very subjective and the roads are crap, but it still does not feel right under acceleration. If anything, I'm reasonably sure it now feels like it's pulling to the left under acceleration which makes no sense to me (it was originally pulling to the right under acceleration).
The wheels from the front which are now on the back have tyres with equal tread. The nearside front wheel now has the brand new tyre.
Could unevenly worn fron tyres cause "pulling" under acceleration? I can't see how as it's RWD?
I have not checked front bushes (in hindsight this was a stupid mistake) as I was convinced the problem is at the rear.
I'm still trying to find an MX5 specialist or company that sets up track/race cars to double check wheel alignment. It's not a track car but those sort of outfits usually spend as much time as needed making adjustments.
Bainbridge said:
@toilet duck your suspicion about the differing tyre circumference between the nearly worn tyre and the new tyre on the same axle is exactly what caused this situation for me, and replacing the worn tyre for a new one matching the other side cured the handling issue.
In my experience my mx5 is very susceptible to differences in tyre circumference.
Thank you for this.In my experience my mx5 is very susceptible to differences in tyre circumference.
I think I am going to get a new tyre fitted and swap the wheels back front/rear, so I have two new tyres across the rear axle.
Thanks again for everyone's help so far
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