Instant and excessive oversteer????
 

Was out driving the car during my lunchbreak yesterday, the steering has been feeling very light in recent weeks. I was transiting from one interstate to another on a long curved onramp - one which I could normally hold a tight radius on at sppeds up to 80.

A California roadslug (indigenous to Southern California) held me down to 65, anyway as I was going around the corner I had to loosen the radius of my turn because the tail end of the car felt like it was going to swing around. I had to do this twice.

It was classic oversteer I felt, but I am at a loss as to what to look for this weekend - should I be looking at the front suspension - the rear suspension - or both. I have new tires on the rear, the whole rear suspension was rebuilt first part of last year.

It was so bad - I'm not even driving it today - nor will I tomorrow. Its probably just as well as I have expired tags and need to smog - which means time for my exhaust swap.

Any tips.?

Re: Instant and excessive oversteer???? (fauxrs)
 

Look at the rear first. Ninety percent of the time, oversteer is because of the rear end geometry. Look for loose sway bar mounts and links, then check to see if your camber is close. Also, your toe on the rear can affect the cornering. Hope this helps, let me know if I can help at all!!

Dave

Re: Instant and excessive oversteer???? (Black Magic)
 

1. Check tire pressures
2. Check alignment, especially rear toe.
3. What parts have you replaced? Did you go with a larger rear swaybar, by chance? Increasing rear swaybar without changing the front causes oversteer. How about shocks? Stiff rear shocks and soft fronts = oversteer. Spring? Again, stiff rear, soft front = oversteer.

Re: Instant and excessive oversteer???? (zwede)
 

No - all factory parts on rear except offset trailing arms - and VB struts - I must point out, this represents a very quick change in cars previous excellent handling characteristics - so something has happened - come out of adjustment - loosened - or something to that effect

Re: Instant and excessive oversteer???? (fauxrs)
 

who did the alignment?

Re: Instant and excessive oversteer???? (Matt Gruber)
 

Bee-line Automotive, simply the best alignment specialists in Southern California IMO - this was back after the rear end rebuild over a year ago. somewhere I have the computer printout they gave me after the alignment.

Re: Instant and excessive oversteer???? (fauxrs)
 

1. loose parts
2. curve had oil on it.
since it was ok for a year, they are my thoughts.

Re: Instant and excessive oversteer???? (Matt Gruber)
 

3. bad tire- tread seperation
i had this happen in 79 and my 76 spun out on a straight road :eek: tires looked ok but had internal faults
FIRESTONE 500's

Re: Instant and excessive oversteer???? (fauxrs)
 

Check the FRONT swaybar. If it is loose/broken it will oversteer. Also check the upper and lower control arm bushings in the front. I had one of the end bolts back out which let the lower control arm slide forward about 1.5". This will make major changes to your alignment.

Re: Instant and excessive oversteer???? (zwede)
 

The VBP adjustable strut rods are notorious for loosening lock nuts. These are
easy to check, though - just a look-see will usually tell. Since you're crawling
under for exhaust work - I'd give them a tweek just to be sure.

:seeya

Re: Instant and excessive oversteer???? (NHvette)
 

Been there, seen that, the lower strut bracket in the rear is off the rear pumpkin...replace and locktite all 4 bolts....

GENE

Re: Instant and excessive oversteer???? (mrvette)
 

Keep it coming fella's - lots of good things to look at here. Thanks :party:

Re: Instant and excessive oversteer???? (fauxrs)
 

Hey fauxrs - I just got mine back today from the welding shop, probably nothing for you, but I had a couple of Nasty frame cracks. Just a possibility.

Re: Instant and excessive oversteer???? (Avette4me)
 

That worried me in the past so when i did the tranny swap I checked for that and found nothing - but thanks - I'll probably check that again - especially at the front shock/a-arm towers.

Re: Instant and excessive oversteer???? (fauxrs)
 

The rubber donut that mounts to the nose of the diff and to the frame. When they rot out and let go they cause funky rear end transistions. Makes the car feel REALLY unstable. I went with a VB poly unit and it did wonders.

Re: Instant and excessive oversteer???? (dman535)
 

Yep - poly pinion bushing during the rebuild last year. That brings up a good point - my trailing arm bushings are poly but the front is still rubber - I figured at worst that would cause an increase in understeer - was i mistaken?

Re: Instant and excessive oversteer???? (fauxrs)
 

I've been getting torque steer in the rear lately and found the bushing in one trailing arm is slipping side to side allowing to toe to dramatically change.

Was it a predictable smooth oversteer or abrupt transition?

Re: Instant and excessive oversteer???? (turtlevette)
 

I felt it before it really started to oversteer - I had to correct twicein the curve - felt very very loose like it wanted to swing around, since I felt it coming on i would say predictable, not like it just came on half way through the corner.....

Re: Instant and excessive oversteer???? (fauxrs)
 

If you were de-accelerating in the curve you probably induced oversteer. Try taking the same corner without having to slow for one of darn slugs. If everything is fine, then that was the problem. When you brake or let off the gas ("lift") into a corner you shift weight from the back end to the front in a major "weigh" (pun intended:D) causing the tail to swing out. It takes practice, but the way out of this situation is to add judicious amount of throttle to transfer the weight back to the rear to give it bite and power around the rest of the corner. Too much throttle and you can make a spin out even worse.

My next bet would be along everyone elses thoughts regarding incorrect tire pressure as the most likely culprit. If you have new tires on one end of the car but not the other and the tread difference is significantly different OR the tires are a different brand this will cause major handling problems too.

Chuck

Re: Instant and excessive oversteer???? (Chuck Harmon)
 

I have been experiencing the same condition. Could excesive wear in the side yokes cause this? With the exception of the third member, everything has been rebuilt/replaced ,but I do know that the side yokes are shot. I also had the rear aligned and am confident it was done correctly.

Matt, I'm running Firestone SS20's(same as indy 500's). Now you've got me thinking :eek: