My '69 Chevelle drifts bad to the left anytime the rear wheels spin. If I power-brake it, it will go all the way around.

It has a GM posi unit. Both wheel start to spin at the same time. The tires are the same size and I checked air pressure. It does it on or off the brake. Any ideas on how to straighten it up?

You may need new plates in the rear end. or maybe some additive from gm for posi but thats mainly for the popping noise they make when the clutches slip in turns.

IMO i like burn outs the drift to one side....they look cool

If drifting left, means that you have to turn the steering wheel to the right to correct, then I'd venture to say that your rearend probably pushes right. Basically, the wheel base is shorter on the drivers side.

Aside from taking it to a shop for a 4 wheel alignment, the most accurate way to check would be to physically crawl underneath and measure from one of the factory reference holes and identical locations on both the right and left side of the rearend (looking at the frame rails from below, locate a hole on each side that are equal front to back of the car. Run a tape measure from the hole on one side to, say, for instance, the shock bracket on the axle housing of the same side. Repeat on the other side.

A quick check would be to measure the wheel base at the rims, however, this can be misleading. Even with the front wheel dead straight, there can easily be some lead, one way or the other, inherent to front end alignment.

Best to reference off the frame (at ride height).

Mine drifts to the left also - as do most Chevelles. Has to do with the unloading of the right rear tire due to torque. Left tire bites in more and is able to pull the car to the left.

Describe your burnout procedure. If you start out too slow, it will be more likely to drift. Get them spinning fast as soon as you can.

try an airbag

Your front brakes might be the culprit.
If your brakes are not applying pressure evenly to both sides in the front, the car can drift sideways while trying to do a burnout.

Check to see that everything up front is working right, no hangups, leaky wheel cylinders etc...

Turning the wheel does not help at all. I just has an alignment a couple months ago. It did it before and after. It got real bad when I put the rolocation brackets I thought it was brakes also but I checked it for holding/not holding. It is worse if I do aa slow burnout but even a "jump on it" burnout drifts.

It does look cool but gets aggravating when just trying to heat the tires, especially in limited space. Seems like the air bag will help. I'll try it.

I'd put airbags in the rear springs as already stated. A little more pressure in the pass side airbag until it evens out, I believe.

Started after adding lower control arm relocating brackets? Now, I really stand by my advice to crawl under the car with a tape measure. I have heard more than once of this problem after adding lift bars, including my own '66, except mine wanted to do it to the right. The right rear was further forward by nearly a 1/4", which pushed the rear of the car to the left (like it wanted to pass the front). Corrected by steering left.

When I asked whether it was straightened out by steering right, I meant while running out the spin, not power braking.

See if two (or three) fingers, will fit between the front of your rear tires and the front of the rear wheel wells. Compare the two sides, I'm thinking that the left wheel will be a tighter fit.

The action of a rear end when applying torque is to lift the right rear tire and plant hard the left tire.
The air bags should help

The issue I see is that more traction on the left rear tire would tend to drive the car to the right and not the left as has been reported. Thus I would expect an airbag to make the situation worse.

I kinda have to suspect Rowdy may be on the right track here.

Get a fat buddy to sit in the right rear for more traction on that side and it will pull back straight. You need more weight transfer going to the right side.

I used to but my tool box back there before that got banned could be a pojectile.

I'll trade you my open rear end for your posi........guaranteed to stop drifting!!

Would a spring spacer help on the one side of the car might stiffen it up a bit.

Measure the rearend to the frame as previously stated. If its sqaure it should sit in one spot.....but it probably isn't..... I have had a limited slip, a spool, and a truetrac diff in my car, they all provided a stationary burnout. I can tell you when all the stock worn out rubber bushings were in the control arms it did want to drift.
With the poly it was fine, and boxed lowers, check out my pics in the sig, the one with the wheels up is stock susp, home boxed arms, poly bushings, no air bags. 1.54 60fts. Now I have double adjustable tube arms, solid rod ends,....much nicer for adjustablity, but the stock stuff will do just fine unless your really putting some HP to it.

Nice ride Blue

Rowdy, thought you meant when power braking, turn the wheel and the back will follow. It does that in my Camaro and Luv. Anyway, I drive it out by turning the wheel in the direction the rear is going. I'll put in on the rack and measure it for squareness. If it's out, how do you fix it?

All the bushings and suspension are new. It did it with the worn out bushings also. Then with the relocation brackets, it got worse. It does act like the passenger rear tire needs more traction. If it isn't the tracking making it spin, I'll add an air bag and try it.

Thanks for the replies.

First of all, if a part hasn't been machined, then they can hardly be considered "precision". Variables in stamping, drilling and welding all come into consideration, which pretty much covers every single piece under your car. For the most part, close, is good enough. But, the addition of relocation brackets (probably the least quality control item in the whole system) likely exagerated what had been a minor misalignment of your rearend.

Assuming that your brackets are bolt on and similar to those that came with my Lakewood Lift Bars (amongst other manufactures), then you would know that the directions aren't worth wet toilet paper, besides kind of a "what looks right" placement/positioning location for the fixed bracket. I welded mine, a little over confident at the time, my penance, two very unenviable grind and weld sessions. It's, oh so enjoyable to purposely produce a personal meteor shower in any confined area, PURE BLISS, when it's overhead.

Now, consider the very name, "RELOCATION". Suggesting that the new mounting point provides better mechanical advantages than the original. The difference is leverage and angle, both of which can have positive or negative effects, all dependant upon the degree to which they are applied and can be plotted within an arc. A variable of either angle or leverage (distance from the fulcrum), from one side to the other, would produce graduated differences throughout the arc.

Think of it this way. One of the holes is off by 1/8", if that 1/8" is further forward and mounting a control arm that extends forward and upward. Well the difference between the two side will theoretically an be 1/8" (actually, a little less). However, the arm would be at slightly different angle and therefore, articulate within a different arc. Which, depending upon the severity, can greatly exagerate a value of differential that otherwise would have been considered acceptable while static.

Finally, was your car FOUR WHEEL ALIGNED, This would not be the standard procedure, especially on a car that normally wouldn't have any provision towards the adjustability of the rearend. It would have to have been at the direct request of the customer. It will usually cost anywhere from an additional 25% to double the charge of your everyday frontend alignment.

Nice ride Blue

Thanks!! :)

Hey Blue,
Hangin' the hides with what rear tires?
Also, were the boxed lower arms mounted in the stock location?
Have you run it with the double adjustable lowers yet? Relocated or stock mounted?

I will be getting some adj. lowers soon (already have Edelbrock adj uppers). I'm debating as to keeping the relocator brackets or not. I've always heard that there is a certain threshhold of power and speed (E.T.), at which point, the "Lift Bar" configuration essentially loses it's effectiveness. Although I don't remember any specific figures, I have to assume that this "transition" happens when a car regularly runs into the high 10's, as most A body cars with the ability to run quicker, have done so, only after evolving to an Anti-Roll system of one kind or another.

I'd like to hear any and all opinions or experiences that would or could substantiate or discredit this observation. Preferably before I start spending in this department, which I hope to do within the next month or so.

Hey Blue,
Hangin' the hides with what rear tires?
Also, were the boxed lower arms mounted in the stock location?
Have you run it with the double adjustable lowers yet? Relocated or stock mounted?

I will be getting some adj. lowers soon (already have Edelbrock adj uppers). I'm debating as to keeping the relocator brackets or not. I've always heard that there is a certain threshhold of power and speed (E.T.), at which point, the "Lift Bar" configuration essentially loses it's effectiveness. Although I don't remember any specific figures, I have to assume that this "transition" happens when a car regularly runs into the high 10's, as most A body cars with the ability to run quicker, have done so, only after evolving to an Anti-Roll system of one kind or another.

I'd like to hear any and all opinions or experiences that would or could substantiate or discredit this observation. Preferably before I start spending in this department, which I hope to do within the next month or so.


30x12.50 ET streets, stock location control arms, with the 30 inch tire my compensated ride height is much lower than stock, I have a lot of rear spring cut out. The lowers are very close to parallel with the ground and uppers are higher in the rear of the arm. At a stock spring height this would not be the case!! I have run the new arms, also with a h-r parts rear anti roll bar, it has a better ride and much more stable, the real test will be with the new engine. I didn't expect much change and there wasn't with my old setup, but I was doing it in preparation for the 496 and NOS. When power levels, converter and gear selection, hit the tires hard enuf, I don't think the relocation brakets are necc. This also comes from a 10" tire car running 8.20's.

Blue,
Judging by the photo's in your signature, our cars have very similar stance and ride height. Is your rearend dimensionally stock, narrowed or minitubbed?

Either way, I'm curious to which tires you have for street use, as well as, rim specs for the E.T.Streets. Currently, my rears are M/T Indy Profile S/S L60-15 on Weld ProStar 15 X 8 (4.5 BS) and the fronts are M/T Sportsman 26 X 7.5-15. I have an additional pair of ProStar 15 X 8 (5.5 BS) to eventually mount dedicated track tires (undecided as to which). In the photos, the rears are NITTO 555R Drag Radials 275-L60-15.

Also, in the launch photo, was this with or without HR Parts Anti-Roll?

15X8, 4.5B.S.,
Same tires on the street, 26x7.50 MT sportsman on front also, moved body mount from inside wheel well to between trunk floor support and frame, stock rearend width. Boxed stock arms, no hr bar in pic. Brian.

OOOPS,

Forgot to attach the photo.

Brian,
Are your fronts the 8 ply version? I tend to believe mine are causing a great deal of my top end vibration (yes they're balanced, it's their roundness that I question).

You must have done some rear wheel well mods to fit those tires with that back spacing. I have removed approximately half of my lip (re-drilled, new screws for the trim). My tires are very similar in size 28 X 12.3 (section width) with 9.5 tread width. The sidewall clearance is minimal, I would be hesitant to run any kind of wrinkle walls as it is with that back spacing. I do believe that the 30 inchers would contact the protruding "bump" that higher up in the wheel well, just above the lip.

I don't think I have the 8 plys, (can't remember, but I could look)
I have about 3/8-1/2" clearance inside and outside.
My fender lip is trimmed also, but still plenty there.
Yes there has been a small amount of wheel well work, very small.
a little stretch in the rear corner. but thats about it.
And moving the body mount that sticks into the wheel well. The tires used to rub on corners, but now zero rubbing with the antiroll. Taking out the spool also helped,.... the axle binds up so much with a spool, it might not matter now with the solid arms, but it would twist up in there on corners with the spool and stock arms. Your car looks nice, I want to put wheel well moldings on mine too. I want to try a 10" rim, the 10.5" tread tires seem to hook a little better on a 10" rim, but I don't know if it will fit. Oh, I actually have 295/65 MT drag radials on right now, they are a little taller and narrower than the old et streets, they drove nice, but did not last long at all and, I just liked the bias ply's better. I will be going back to the bias ply's when I get the car back together. Then I'll be able to tell you how the new susp. works....Should be close to 700hp, plus a 300 shot after it sorted out NA.

Get a fat buddy to sit in the right rear for more traction on that side and it will pull back straight. You need more weight transfer going to the right side.


I am immediately available for BEAT RUNS!

I did the single pass side airbag and you'll be able to tweak it to run straight as an arrow while spinning 'em out of control bouncing off the rev chip. Yes, its a stupid kid trick, but still I disagree with yost, the 7000 rpm smoking passing manuever is still the coolest.

Think the gal in the white Expedition, on the phone, hogging the road, wet her little panties when Old REd screamed past her smokin' em'! :cool:

I'm sure the local fuzz would have disappointed in me, but as Allstate says, I was trying to make a better driver out of her - I WOKE HER UP!."

But I digress.....

BTW, I then added a sway bar, and I dont even put any air in the bag anymore. Funny thing, if I take it out, the rear pushes out again. So I left a deflated air bag in place. Go figure. It was VERY sensitive to changes in psi.

.... and I dont even put any air in the bag anymore. ... So I left a deflated air bag in place.

I think you must maintain a minimun of 5psi in those bags to keep them from rubbing up/down inside of the spring. This could eventually tear the bag. Just though I'd pass that along.

I agree with rowdy. If you changed something in the rear and now it does it bad, for sure I would start measuring yoru're wheel base side to side.

Stop doing burnouts or maybe an open carrier?

I measured it today. I took measurements from a couple different points of the frame to stock lca bolt holes on the axle. It is close, very close. Hard to really get a measureable difference. I checked the relocation brackets and I luckily did a good job of keeping everything square when I welded them in. The LCA's will bolt to the stock hole and swing down it's natural arc and bolt into the RLB holes without adjusting the rear end. I guess the air bag is the next move.

Stop doing burnouts or maybe an open carrier?


Don't know why I didn't think of this, lol.:)

How does it leave the starting line? Have you checked the circumference of the back tires? You will be suprised at how much tires can be different in size when they shouldn't be.

It will leave straight and true as long as it hooks. If it spins, it'll try to swing. I didn't measure circumference but I'll look into it.

I think I would get a 4 wheel alignment done after that rearend work all it takes is 1/8" and you can miss that with a tape measure.