My car pulls to the right when I hit the gas real hard. I just rebuilt the front end, installed new TA radials and had the car alighned. Then, when I let up on a hard acceleration, the car pulls to the left if the RPMs are high (sort of a downshift)

Could this be caused by the body flex of a convertible?

check the rear springs, shackles, bushings, ubolts, shocks...

Just a guess, but it sounds like a textbook example of a bad drag link.

Obviously, you have a right-handed car.

- Jake

Is the car's name Christine?

Sounds like the rear end housing isn't square in the car. Have some one drive the car in a straight line while you follow. If it "dogtracks", you'll have to check the mounting pins on the leaf springs. Another check is to look very closely at where the rear tires sit in the wheel well on both sides.

Thanks for the thoughts. I can tell you the rear is NOT stock. It has multi-leaf rear, KYB shocks and a 3.73 posi.

Also, anybody know how to install the pinion bumper above the rear diff? I discovered mine was missing and got a replacement. But, I can't get enough force to the rubber block all the way into the hole in the floor pan.

Oh boy, was that a pain.

I first let the bumper soak in very hot water for about 10 minutes. Then I put vasoline on it and coaxed it into place using my garage jack and a piece of 2x4.

Sounds like the diff may not have been installed properly. Get two straight 8' 2x4's and a friend, and line them up so they are parallel to the body. Place the board against the rear tire so it touches both sidewalls above where the tire bulges at the bottom, and so it almost touches the rocker panel. If you have a couple of coffee cans, you can leave it in position while you do the same to the other side. Now compare the two sides to see if the boards are truly parallel, or if they both point to the right or left.

Good thinkin, TOH...I probably wouldnt have thought of that. Salmon, how do you remove that bumper without damaging it? Just yank it out? I have pretty much everything else stripped off the underside of mine and its almost ready to be coated and Id prefer to remove it rather than just mask it off. Thanks, Charlie

The old rubber pinion bumper is 35 + years old. Just "forgetaboutit". There is NO WAY it's going to come out without being destroyed.

The new repro is very good.

Well it seems to still be in fine shape, so I will just leave it in place and mask it off. Thanky salmon.

Rob, I may be of no help... but I often have much the same problem... when I mash the gas, the car just goes to the right... then the left... then the right... then the left and sometimes in big circles... and smokes something fearce... then all seems fine after I let up on the gas... but sometimes after doing this test, it makes me see flashing red lights... must be from breathing all that smoke or something? Haven't quite figured that one out yet...

Is that the problem your having too? I know Q often has similar problems...

Seriously though.. sounds like the rear is either shifting, and or as suggested not set square or properly. I'd take a good set of measurements such as Brent suggested, and then between front and rear tires on both sides... perhaps the rear is angled slightly (one side more forward then the other) Or maybe it is shifting or moving slightly?

Let us know what you find? I guess I'll just have to learn to live with the problem I'm having on mine...

Brett - 67 Drop Top 455!

Brett, ya know theres some good aftermarket anti-"red flashing lights" components out there now and readily available. I think theyre called radar detectors or something like that. :p
P.S. Should I email Quenton and enlighten him on this new technology too?

radar detectors?maybe i need one of those.im getting too many speeding tickets.

LOL Terry...glad ya feelin better bud.

i learned a long time ago if you cant beat'em...join'em
the pay stinks...but what i save in tickets and higher insurance has got to be worth alot.

back to the post :
can the posi not be tracking the same on both sides? one side pulling more than the other. if this is even possible?

ok... back to pulling over kids in cars way cooler/faster than i had at there age

thank ya charly.im getting better.and to answer your question jerry,unless your axles are welded together,you have a limited slip differential.one wheel will disengage when cornering as it is supposed to.

If the diff is not square to the car, the car will move to the side away from the direction the diff is pointing under accel., and to the other side under engine braking (not regular braking as much). Oval track racers use this to their advantage when setting up the car.
A variable effect can be achieved by installing solid bushings on the left side and leaving the rubber on the other. This allows the rear end to point into the corner when on the gas, and to point out under braking to help pivot the car on turn-in.
Doesn't matter if the diff is posi or not.
The issue of excessive chassis flex still looms, but do some measuring first! I once had the pleasure (!) of driving a car (not mine) on the oval that switched back and forth between oversteer and understeer, depending on which bump it hit last. Later was discovered to have a broken frame (still finished third, though).

Thanks for all the help. However, I think I found the problem.

I rebuilt the front end over the holidays. I noticed the drivers side gap between the fender and the top of the tire is about 1 inch greater than the passenger side. Also, I hear a popping sound when going into reverse from the driver's side suspension.

I think I may have not set the spring in the pocket all the way. (doah!!) Thoughts????

Hey Rob I had the exact same problem with an improperly placed front spring when I bought my car. I just placed that corner of the car on floor jacks so as to suspend the wheel in the air. I then went underneath with a small sledge and placing a 10 inch piece of 2x4 against the top of the spring, I whacked at it and it popped the spring into place. It worked pretty smooth. I don't know if you were looking for help or not but there it is my 2 cents. Mt ride is a 67 326 non H.O #'matching ragtop. Regimental Red with parchment top and interior. Jimbo

Jumbo - THANKS - I really don't want to tear down the entire assembly.

Did you hit the spring from the side or pull the shock and hit it from inside/under?? Please explain a bit more!

Thanks again.

Hi Rob I placed the 2x4 lengthwize up against the top of the spring on the side that was out of line and gave it acouple of wacks and it popped in. By proppng the front end up and letting the wheel hang in the air it takes the pressure off the spring. So determine the point on the top of the spring that is out of line, either to the left or right or front or back and place the 2x4 on that spot and have at er. Hope that helps. Jimbo

Rob I did not have to pull the shock. And I hit the spring from the outside of the spring and from under the car. Hope that makes sense. Jimbo

Hmmm. I'm doing my springs right now and I think you were lucky on that jimbo I got one side in perfect and can see the end of the spring in the hole on the top pocket of the frame - but it wasn't easy. Took many attempts. If the spring is not in there perfectly, simply whacking it with a board will not get it to sit in the pocket correctly. He may have to try and use a spring compressor and twist it into place, or what I had to do which was remove the spring, compress it, hold it up there and get the end of the spring to lign up with the hole in the pocket, then with the other hand jack up the lower control arm until the weight of the car is on the spring, then re-check if the spring is still seated properly (it tends to twist when you start to compress it) then re-connect the lower ball joint and remove the spring compressor. Others seem to have success with the all thread method, but I don't see how you could get an uncompressed spring to sit on the lower control arm without messing up the top alignment. Just my 2 cents. Good luck.

The previous owner of my car had just put a new front end on the car and just did not get the front left spring in all the way. For my situation this teqnique worked I guess I got lucky since I have had no problems with alighnment of handling. My spring was sitting on the lower control arm just fine it was out of place at the top. Jimbo