Subframe Alignment Issues

[SSL]

Made my first attempt to string align my '68 Camaro this weekend and determined that the subframe is misaligned by ~3/8" to the passenger side...

Any recommendations / good methods for aligning it with the body on and engine in the car?

Thanks in advance,
Steve

[1969CamaroRS]

Hi Steve,

I am assuming you mean 3/8" off center to the right for the front sub-frame (as opposed to the angle in regards to the centerline of the vehicle). I think 1/4-3/8" was pretty much within standard tolerance.

Have you checked any points on your subframe to the Fisher body specs?

From: http://www.1stgencamaro.net/frame.htm

If you do that I think it should tell if you you are mostly straight of if there is an issue with something being bent, that you should worry about.


I just recently aligned mine. Did you check to see if your rear end was centered in the vehicle? Mine was about 3/8" offset to the passenger side and was throwing off all the other measurements because of that. I checked before I redid my front and rear suspension so I would have a baseline, which after the suspension was redone ended up fixing the issue and was able to get everything nice and dead on.


As far as getting the 3/8" mis-alignment out for the front sub-frame. You could try supporting the car on jack stands, loosening your body mounts and use some bar clamps between the sub-frame and body to nudge things in place. It is going to be harder to do with motor in due to the weight. You should have at least 1/8-1/4" play to help correct things, but I am not sure I worry too much about 3/8" (I know I am picky too).

Perhaps someone with more experience will chime in, but I hope this helps!

[SSL]

Thanks Ed. Excellent information.

I did check that the subframe wasn't bent before installing it and did align the rear end first.

Besides seeing it with the alignment strings, the tire to fender gap is noticibly different side-to-side. I can see the fender gap difference just by looking at it now that I know there is a problem.

The bar clamps are an interesting idea but I'm not sure where I can "grab" onto the body to move the frame. What section of the body were you thinking about that wouldn't harm the exterior paint?

[1969CamaroRS]

If you under the car there is "lip" underneath on the side that you could use to push or pull on with the clamps. Here is a pic since most of us are visual:


I didn't bend anything when I did it, but I had the motor and the front clip off. I figured its a lift point on the car so it shouldn't hurt to put a bit pressure on it. Remember you aren't trying to bend anything just push/pull the front clip into he proper place (within its free play) and hold it while you snug down the body mounts. You could also put pins in the alignment holes see how close they are as well.

If your tire to fender gap is really off but the rear end is centered then something must be off about the body. Maybe drop a couple plumbs on different reference body points see if you can figure out what is off about the body? Sorry only done this a couple times (suspension going off and on) so I'm sure there are better ways to check for your specific problem.

[Vegas69]

Hate to be a simpleton but do the holes line up in the front sub? I guess I don't see how the wheels could be that far off if the holes in the frame line up with the body holes. Unless the front sub is completely tweaked.

[1969CamaroRS]

Also one thing isn't clear is the tire to fender gap off on the rear or the front or both?

[SSL]

Sounds like I might have caused a little confusion... The rear end is aligned properly and the rear wheel fender gaps are perfect.

When the subframe was installed, I did use the alignments holes to align it but it seemed to be a gross alignment method.

The front fender-to-tire gaps are not the same side-to-side. Using a straight edge across the front wheel openings (at the mid-point body line), the passenger side has about 1/8" gap and the drivers side is about 1/2".

With the subframe loose, I wonder if the subframe-to-body alignment holes could be used to move/pry the frame into place?

[1969CamaroRS]

Ah I got it now. How is the front clip alignment with the rest of the body?

Can you get a centerline of the rear suspension and see where it sits with regards to the centerline of the front sub? Is your front and rear frames square and straight with each other?

Something is off on the front, just got to figure out if its the body or the sub.

[Vegas69]

Frame is tweaked or your wheels are *******s.

[SSL]

The front bodywork is aligned and definitely not the source of the problem but now remember why the subframe is out of alignment from the vehicle centerline.

About 4 years ago, I needed to replace the oil pan gasket. The car has a Canton road race pan that needs additional clearance over a stock pan to remove. I chose to drop the subframe and keep the engine lifted rather than pulling the engine. When reattaching the subframe, I didn't spend extra time to realign the subframe thinking it would be "ok" since it was only vertically dropped. Looks like I was wrong...

While under the car, I noticed that there is a transmission-to-tunnel clearance problem on the driver's side. This is probably how the subframe got "pushed" to the right when bolting it back in. I can trim off an unnecessary lifting loop from the trans case if I can find a saw small enough to get into the tight space.

Funny how you forget things you did during the span of an 8 year project...