Pulls to the right when I 'get on it'

[dpariso]

Anyone have this problem? When I get on it, the Cobra drifts/pulls to the right, and when I let off the accelerator, it corrects itself. Normal acceleration no probs.
Recently I replaced the rear lower control arms and had a 4 wheel alignment.

[Alex_V]

I am far from an expert on this, but I would probably mention what your suspension setup is.

[GoDadGo]

Questions:
.......Did it do this before the car was aligned?
.......Are your tire pressures properly set?
.......Is your rear an IRS, 3-Link or 4-Link?

NOTES:
.......These cars often baffle folks who are actually parts changers who call themselves mechanics.
.......My pal Dave & I brought his 33 HR in to do a final alignment & the shop totally blew it.
.......We had is very close using the string method & a couple of angle finders.
.......They admitted that they didn't know how to deal with his car.

Good Luck!

[dpariso]

Good point Alex.
3-link rear suspension / FFR tubular lower control arms
8.8 Rear Differential w/Tru-Trac Detroit Locker 3.55 gears Solid Axle with Girdle cover to strengthen the carrier

It never pulled to the right before the alignment or replacement of the lower arms
182907

[rthomas98]

I would double check your rear axle position side to side. Take the wheels off when you do this as the rubber can mess with the measurement. Make sure the distance from the hub to the shock mount is equal side to side. If they are check and make sure the panhard bar is tight and the bushings/bearings aren't loose. Then I would check driveline angle. Whatever your driveline angle is measured at the back of the transmission should be equal but opposite at the pinion. So if you are 2 degrees down at the trans your pinion should be 2 degrees up. This can only be measured with the car on the ground not on jack stand. I recommend getting some raceramps wheel cribs. This get the vehicle in the air to work but allows it to sit on the wheels.

[Avalanche325]

4 wheel alignment with a 3-link? I guess that the standard these days, even if there is nothing to adjust. Did your numbers show that the rear axle is straight?
When the car is sitting on the ground is your panhard bar level? Check you side to side like rthomas98 said.
I would nut and bolt check the rear suspension. Maybe something is loose.
Check that nothing is binding.
Check the ride height left to right.

With any differential that drives both wheels, it is pretty normal for the rear to move around when you break loose. Detroit Lockers are known to be particularly twitchy as they are serious about locking.

[compuatic]

Check your brakes. Not an obvious issue that would give these symptoms. After a drive, the discs should be similar temps otherwise you have a bad caliper somewhere

[SJDave]

Does it also pull left or right going over dips or bumps in the road?
if it does, I believe the alignment shop might have blown the “CASTER” setting.

I just replaced the upper Aluminum adjusters to Steel versions and wanted to go from 3 degrees to 8 degrees as I just installed E Power Steering. Well I messed up my calculations and ended up with 2.5 degrees difference. Car was scary to drive!!!!

[CraigS]

I 'think' it best to concentrate on what has been changed so look at the rear axle. Obviously check the bolts for the LCAs. But also check the bolts for the bracket they attach to under the axle.
182935
The green is welded on at the factory. The red we bolt on. If it moves slightly, it changes the effective length of the LCA. I had the same thing going on and it took a while to find it because the movement is so small. For a while I got it fixed by super tightening the bolts. But autocrossing on Hoosier AX tires really loads the suspension so I ended up welding the bracket in addition to the bolts.

[GoDadGo]

Steve's Stupid Questions:

Since this is a 3-Link, assuming all control points are properly torqued:
1. Could the issue be that the new control arms are flexing?
2. Could the bushings simply be softer than the bushings on the control arms?
3. Could a combination of both scenarios be creating this handling issue?

Good Luck & Hope This Helps!

[FLPBFoot]

A long shot but there are two mounting holes for the lower control arms. An upper and a lower. Are both sides the same? Did you change from lower to upper with the new lower control arm installation?

[MB750]

Wow, this thread confirms that I'll do my own alignment.

[Jacob McCrea]

Hopefully this adds to the discussion:

I have had two vehicles that wanted to steer under throttle. The first was a 1970 Grand Prix. Some idiot put a 7/16 bolt in place of a 1/2 bolt at the front of the driver's lower control arm. That and bushings from 1970 allowed the rear end to shift out of alignment with the centerline under throttle. It essentially steered like a forklift. A 1994 Pathfinder did the same thing due to the rear control arm bushings being shot.

Both were open differentials, so a single rear wheel was applying leverage to twist the axle out of alignment. With a good locker or limited slip, I don't think the problem would have been so noticeable, because the axle would be pushing forward roughly equally through both tires. In both cases new control arm bushings and the right hardware solved the problem.

[chmhasy]

When you are getting on it, are the rear tires breaking loose from the pavement?

[GFX2043mtu]

Check the thrust angle of the rear diff. Tape measure is good enough. If that is ok then look for loose parts / bolts in the suspension system that can cause slight movements when loaded and unloaded.

[Ford & Jeep Fan]

Anyone have this problem? When I get on it, the Cobra drifts/pulls to the right, and when I let off the accelerator, it corrects itself. Normal acceleration no probs.
Recently I replaced the rear lower control arms and had a 4 wheel alignment.

You have a loose passenger side lower control arm Bolt or bad bushing. I've seen this before. 99-04 Jeep Grand Cherokee's have a very similar 3 link rear suspension. If one of the lower arm bushing go bad it lets the axle move forward under acceleration on that side and vehicle's rear axle thrust angle will change quickly.

[mrmustang]

Anyone have this problem? When I get on it, the Cobra drifts/pulls to the right, and when I let off the accelerator, it corrects itself. Normal acceleration no probs.
Recently I replaced the rear lower control arms and had a 4 wheel alignment.

Lots of good ideas above, all missed the simplest of them all, tire pressure. What is your "cold" (before the car is driven, first thing in the AM) tire pressure in your tires?

Then again, while we are at it, what tires are you using? How old are they (check dates on tire itself)?

As already stated again, is everything torqued properly? Even things you did not touch need to be checked from time to time.


Bill S.