Pull When Accelerating/Decelerating
 

The last time I was at the drag strip I noticed a pull to the right when I would back off the throttle at the end of a run. After having look underneath when I got home I found I had lost a rear sway bar bushing bracket so I was confident that that was the cause. I had the bracket replaced and an alignment done. Seemed all good but I still am getting a pull to the left under acceleration and then back to the right when I let off the throttle. Anyone had this happen? Any ideas?


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will do this if tire pressures are off from side to side

Hrm... that was a thought but I just checked and the pressures are within one PSI of each other.


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Sounds like something in your suspension is loose or broke causing an alignment shift as you accelerate or decelerate. Most likely in the front but maybe in the rear. I'd get it up on an alignment rack and check it out. I wouldn't use a lift that will let the suspension droop. It might mask the problem.

Headers clear the steering shaft?

Yeah... don't see any indication they have been hitting the shaft.

I'm at a loss on this comment. I fail to see how a header tube rubbing the steering shaft can cause a car to pull. Care to explain your thought process?

You had a chance to put the car on a rack yet?

Not yet. I had it up on jackstands the other night but didn't see anything obvious. I think I need to get it up in the air with the suspension under load to get a better idea. (Dang... shoulda bought those Race Ramps)

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If the header on the drivers side is touching the steering shaft. As the motor torques it will raise on the drivers side forcing the shaft to pivot away from the motor forcing the steering shaft to the left. When you let off the throtle the motor would return to a nuetral position, pulling the shaft down forcing a right pull. A broken motor mount could also factor in to this scenario.
Kind of at the outer limits of options but the OP is looking for suggestions.

At this point I'm happy to entertain all ideas :)

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sounds like a loose end link or something to me. or a bushing not in time.
my car does it a lil and always had. but its nothing bad the average person wouldnt know it.

So I spent quite a bit of time yesterday checking everything out and can't find anything that looks like a problem. I rechecked all the bolts for tightness, pried and pulled on all the suspension arms, links, etc. Didn't find anything other than what I would expect as normal movement from the bushings. I'm beginning to wonder if I'm just now noticing the pull since I have added my cam, headers, etc earlier this spring. Maybe it has always been there but is more pronounced with the extra power.

There other thought is that perhaps I'm experiencing the toe rods and trailing arms flex/bushing movement. I wish it was in the budget and I'd upgrade them to see if that takes care of the problem.

The only other thing that is odd is I have worn my left rear tire out before the other three, by quite a bit. I'm down to the wear bars yet the right side is still 4/32-5/32" remaining. I'm obsessive about keeping the tire pressure at spec and I don't do a bunch of burnouts, even at the strip... just a quick couple of turns to clean 'em up.

I'm hoping the recent alignment is going to take care of the premature tire wear but I'm still bothered by the pulling.

Any other ideas? Similar experiences?

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So I'm at Discount Tire getting my prematurely worn-out rear tire replaced. After driving it down here I'm still convinced there is something wrong. It is a very pronounce pull to the left under acceleration and a shift back to the right when I let off. Feels like I'm driving a front-wheel drive vehicle with torque steer.

I definitely cannot find what's causing this. Might have to take into someone with better equipment to figure this out. (Dang! I had having other people work on my car!)


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Have you done pfadts "bushing timing" yet?

Yep. I had a local alignment shop do that when they did the alignment after the drop. (Although I have no faith in that shop as I had to tell them how to do it.) Since then I've had it aligned again at JDP Motorsports. They didn't see anything obvious to cause the pull. I think I'll focus on the front suspension and see if anything shows up.


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I don't have a clue since you found everything to be tight. I worked on a car once that had bad radius arm bushings and the caster would shift when he let off the gas and pull. I dunno man.

Make sure your control arms are not bent or anything. I had a bent front lower control arm and 2 dealers several alignments and other shops, over 45 days in the shop over 1 1/2 years later I went to get an alignment. I know the guy so he let me checkout my car myself on the rack. Low and behold I spotted the bent arm. Fixed it and all is better.

When I turn off traction control, the rear of my car seems to slide to the right. Its done this every time I floor it. Its probably because I have different tire pressure on left side and right side. If not that is strange!!

Which control arm was bent?


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Right lower control arm. But I hit a curb to avoid an accident. My thought was to just make sure nothing is bent or out of place. Tons of professionals missed my problem. Always best to look at it yourself.

I'll get it in the air this evening and have a look around. I've not had any encounters like that but you never know.


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One or more springs not properly seated or has lost some free length?

One or more bad shocks/struts?


Norm

Problem appears to be solved!

I put the front end up on jack stands last night and went over everything I could think of. Bushings seemed to be just fine, fasteners were all tight, wheel bearings were fine. I mean out of desperation I even checked to see if the sub frame bolts were all present and tight. Found nothing.

Next I put the weight of the car on some 4X6 blocks stacked up so I could still get underneath to see if anything seemed different with the weight of the car on the ground. Still nothing. I was about to give up when an idea came to me. I wonder if the front sway bar is maybe biased right to left. I unfastened the left lower end link heim joint and low and behold I couldn't pull it out of the sway bar hole. I had to pull on the bar quite bit to get it out.

I wound the heim joint in enough to let it slip into the sway bar hole, torqued it down and took it for a short spin. Sure enough... the pull to left under acceleration and pull to the right when backing off is gone! I had no idea that a sway bar would have quite that much influence going down the road.

I'm thinking that between bushing timing and two alignments since putting on the sways and drop springs it obviously is sitting a bit differently than when I originally I hooked up the end-links. I'm not 100% sure I had the front suspension completely settled last night being up on 4X6 blocks so I think I'll have the end link adjustment checked on an alignment rack just to be sure. Also although the pull is gone during acceleration/deceleration now I have a pull to the right going down the road at cruise. I'm sure the sway bar being biased caused the recent alignment to be incorrect so I'll have them recheck the alignment at the same time.

Woo hoo! What a surprise! ... and a relief!


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Glad you found the problem and glad you reported back with the solution so others can learn from this. To many threads go dead with no solution reported and nothing learned from it. Bravo!

glad to hear you figured it out. it can be very frustrating as was my situation. now since you mentioned this I am going to check my end links lol