I noticed this problem before I did a complete rear end swap, along with all new mounts, springs and schakles. The rear end sits farther forward towards the front of the fender well on the driver side then the pass side does. The driver side tire is 2 3/8 from the front of fender well, while the pass side tire sits 3 3/8 from the front of the fender well. Is this normal on these cars? I cant think anything on the rear end or springs would be causing this since it is the same thing as before I did the whole swap. Anyone have an insight to what may be causing this? Thxs!
Not normal. But you need some better reference points than just tire-to-wheelwell to help understand what is wrong.
Take cross measurements from points on axle to other symmetrical points on the unibody...like maybe front crossmember bolts or alignment holes. This will help confirm whether the axle itself is dog-legged in the rear, or if you possibly have just a replacement quarter panel sheet metal that was/is poorly placed from a prior accident or rust repair.
I'd also verify wheelbase left side to right side. Make sure your front wheels are pointed perfectly straight before taking wheelbase measurements.
These will give you clues as to what part of the car is crooked, and what part is straight.
Rear axle positioning is all established by the locations of the front leafspring pockets. If you find assymetrical cross measurements at the axle, you will likely find assymetrical cross measurements from the bolts of these spring pockets. If this is the case, then you likely have unibody damage from a prior accident or improper structural rust repairs.
Thanks Craze, I will try and take some measurements tommorow. I am hesitant to use the subframe to do any measurement cause I have front end alignment problems which I think are due to the subframe not being straight on. I will start with the back area first, thxs
Agreed you should not use the subframe itself...that was not my intent and I should have been more clear...subframe BOLTS and subframe ALIGNMENT HOLES are good reference points...and these are on the unibody itself, not on the subframe. I don't think you should focus only in the rear area, as it defeats the value of cross measurements. Cross measurements are more useful and accurate the longer you go under on the car. But for rear axle purposes don't go past the firewall on a car where you suspect possible subframe damage/misalignment.
So I agree you should ignore the subframe itself, but choose some symmetrical reference points at the front of the unibody...near the firewall. You'll find some subframe alignment holes up there that are very useful. Make sure you use reference points found on STRUCTURAL components that appear to be original. Do NOT use floor pans if there is any chance they have been replaced or patched before. Drain plugs for example can be set in random locations during rust patchwork.
And of course wheelbase itself...easy and informative in a situation like yours, and you don't even need to crawl under the car. But it does obviously use the subframe as part of the equation, so it's only one clue.
This page from the Fisher service manual may be useful for you, but most of these require a tram gauge to be accurate and on-plane. Most of these don't work perfectly with just a tape measure alone...especially with driveline and such installed in the car and interfering. But with some time and plumb bobs it can be done. Most critical comment on this page is that it is much "more important to be square onto itself" than to match these numbers perfectly. These were NOT robotically built...so there was lots of variance between cars right from the factory. But it gives you visual ideas of what you're trying to do anyway: http://1stgencamaro.net/frame.htm
You may simply have a situation where you have a poorly placed aftermarket quarter panel on one side, and an OEM on the other. Hopefully the structure itself is straight. That's what you need to figure out. All cross measurements must be within 1/8" of equal. This defines a straight car of this era.
Have you inspected the pin in the center of the leaf springs? You should be able to see it through the hole in the bottom of the plate that clamps the rear to the leafs and also serves as the lower shock mount. Check both sides. It is very possible this is not lined up, if so your rear is not sitting square on the leafs.
Have you inspected the pin in the center of the leaf springs? You should be able to see it through the hole in the bottom of the plate that clamps the rear to the leafs and also serves as the lower shock mount. Check both sides. It is very possible this is not lined up, if so your rear is not sitting square on the leafs.
Yes, I rechecked it, and I also had this problem before I did the rear end swap which even then the the pin was lined up properly, thats why I trying to figure out what could be wrong. I can only hope that it is a bad quarter panel install that is throwing it off.
Have you inspected the pin in the center of the leaf springs? You should be able to see it through the hole in the bottom of the plate that clamps the rear to the leafs and also serves as the lower shock mount. Check both sides. It is very possible this is not lined up, if so your rear is not sitting square on the leafs.
Yes, I rechecked it, and I also had this problem before I did the rear end swap which even then the the pin was lined up properly, thats why I trying to figure out what could be wrong. I can only hope that it is a bad quarter panel install that is throwing it off.
Next I'd measure from the front leaf mount to the pin(s). If that check out then yup, has to be the quarter. I think there is usually evidence of quarter replacement visible somewhere, inspect the trunk real good. I still hope it's a leaf problem for you though. good luck.
Have you inspected the pin in the center of the leaf springs? You should be able to see it through the hole in the bottom of the plate that clamps the rear to the leafs and also serves as the lower shock mount. Check both sides. It is very possible this is not lined up, if so your rear is not sitting square on the leafs.
Yes, I rechecked it, and I also had this problem before I did the rear end swap which even then the the pin was lined up properly, thats why I trying to figure out what could be wrong. I can only hope that it is a bad quarter panel install that is throwing it off.
Next I'd measure from the front leaf mount to the pin(s). If that check out then yup, has to be the quarter. I think there is usually evidence of quarter replacement visible somewhere, inspect the trunk real good. I still hope it's a leaf problem for you though. good luck.
Thanks quick68bird, but what pins are you referring to? The pins in the center of leaf spring? Or from the center of the bolt on the front of the leaf springs to the center of the bolt on the shackle?
Verify that the hole drilled in the middle of the springs is in the same location on the left and right. So from anyplace at the front of the spring (mounting bolts, center of eye) to that hole for the pin.
Next I'd measure from the front leaf mount to the pin(s). If that check out then yup, has to be the quarter.
Quick68bird, I have to respectfully disagree with this statement. In fact I can say with 100% confidence that this measurement WILL check out, on all cars, no matter how badly the unibody may be twisted or wrecked. The only thing that leaf mount-to-pin measurement verifies is that the 2 leaf springs are the same length to the pin when compared to each other. It would identify a bent or defective leaf spring. But it tells nothing about the car itself. And the fact that he's had 2 sets of springs on this same car, and both sets have resulted in the same problem, shows he doesn't have a spring problem.
Either the quarter panel is out of position, or the front spring mount (and many other things) are out of position.
Still need to verify position of the leaf mount buckets relative to the rest of the unibody before determining the quarter panel position is definitely the problem. Must ignore the springs, pins, and the axle entirely to do this.
I agree with measuring from front spring mount. But not to the pin on the axle. Instead he needs to measure from the front spring mounts forward to a fixed point on the unibody...toward the firewall. And also backwards all the way to fixed points toward the end of the rear frame rails. Compare these measurements left to right in a straight line, and left to right in a cross. This will ID which part of the unibody is out of square, or will hopefully confirm that NONE of the unibody is out of square. This is the critical question.
Thanks Crazecar, you explained it as to why I need to do what you suggested. It makes total sense to me now. I was going to do all of the suggestions, but will just do the fixed point measurements.
ok, so I dont have the foggest clue on how to get any accurate measurement with a tape measure trying to crawl under the vehicle and route a tape measure over and under anything. Matter of fact, there is no way to get a accurate measurement that way, so can someone please tell me what the easiest way to do measurements with out buying anything special??
Plumb bobs. If you don't have any you can make your own out of strings and heavy washers. (Actually light weight fishing line and heavier fishing weights are sometimes ideal for this if you have them.)
Park car on flat concrete. Tie/tape strings with the weights tied to them very carefully from your reference points on the car and let them dangle about 1/8" from the ground but not touch. Make sure the weights are heavy enough to allow the strings to pull perfectly straight.
After weights stop swinging draw X's with a sharpie on the concrete directly below the lowest point of the washers. Label all the marks with masking tape tags (or write on the concrete if you don't care) so you remember exactly what part of the car the X's represent after you move the car. Now drive the car away and carefully measure distance between all your marks on the concrete. You might not even need jackstands to do this if you can reach all the points you want to measure by laying down and reaching under...
OMG, you are a smart person!! Why didnt I think of that? lol cause I aint that smart...lol You make it sound so easy! Thanks so much, that is BRILLANT!! I am just a dumb retired Marine that struggles with some of this auto stuff, maybe it's just me over thinking it all...lol Thanks again crazecar!
Wow I've been called a lot of things. Brilliant is NOT one of them LOL...plumb bobs are just an old school measuring trick...more from construction/renovation of homes than from cars.
Just remember your tolerance is 1/8" variance or less. That's not much, so this takes some precise measuring. So be patient and take your time doing this, and be very accurate with your marks and in mirroring the locations of the string at each point on the car. And don't lean on the car accidentally and let it roll 1/4" when you're halfway thru making marks!
In a perfect world, you borrow a tram gauge from a body shop. It's largely an obsolete tool that most good body shops have laying around and one might be willing to loan to ya if you happen to know someone that works there. Most body shops use computer measuring equipment these days for frame/unibody measuring and let their old tram gauges gather dust. They're awesome for precision/comparison measuring while straddling things like driveshafts, exhaust, and all the other garbage that's probably in your way. But you'll need the car up on jackstands to use it for sure.
Awww, you're too modest. The smarts come with age and experience. The impressive thing is when a young person comes up with and old idea. You just have to be impressed by that.
Ahh, I missed that he replaced the springs. An inch is a lot to be off. We can't see the car but if it was collision damage I think there would be some buckled sheet metal and some really bad panel gaps. If the door is not right due to the quarter the entire front clip will be misaligned. But I am very picky. So if its not the spring I hope its a poor repro quarter. Good luck.
OK, put your car on a level clean floor and raise it up on some tall jack-stands. Get a plumb-bob and a piece of 1" round iron/steel whatever, and a felt tip marking pen. Go to "the first Gen Sight"'s library and go to the "frame and body mounting" section. There you will find the measuring points on the frame/body. Use the plumb-bob to transfer these points to the floor where you mark with the pen. Measure between the points to check alignment. Also check the sections for mounting the frame subframe and fenders. The Fisher body manual may help as well.
Sorry I had a brain malfunction this morning, I think it's a 5/8" rod or bolt that can be placed through the hole in the frame and into the hole in the body near the rear body-mount on the front subframe. Some master alignment gauge holes are one inch and you must measure to the center, putting a one inch dowel into the hole and measureing from the outside is easier than estimating the center of the hole just subtract 1/2" from the measurement.
lol, thanks Blue, I got a little confused when you said 1" and was thinking am I suppose to sit on that cause I dont know what a 1" round is going to do but hurt me...lol Thanks for clearifying that!
Wow I've been called a lot of things. Brilliant is NOT one of them LOL...plumb bobs are just an old school measuring trick...more from construction/renovation of homes than from cars.
Just remember your tolerance is 1/8" variance or less. That's not much, so this takes some precise measuring. So be patient and take your time doing this, and be very accurate with your marks and in mirroring the locations of the string at each point on the car. And don't lean on the car accidentally and let it roll 1/4" when you're halfway thru making marks!
In a perfect world, you borrow a tram gauge from a body shop. It's largely an obsolete tool that most good body shops have laying around and one might be willing to loan to ya if you happen to know someone that works there. Most body shops use computer measuring equipment these days for frame/unibody measuring and let their old tram gauges gather dust. They're awesome for precision/comparison measuring while straddling things like driveshafts, exhaust, and all the other garbage that's probably in your way. But you'll need the car up on jackstands to use it for sure.
Have to agree with Firebob , I've watched your posts for a long time and you know what your talking about. Your either a smart man with some bodyshop friends or a bodyman turned supplier rep. 3M maybe? at any rate the only thing I have to add is an easy test that I always use is to look across the face of your rear tires towards the front of the vehicle. you should see the outer edge of the front tires on most vehicles, if you see more of one front tire than the other then your tracking is off.
OK, so here is an update on my measurements. I have one QUESTION with the link Crazecar posted http://www.1stgencamaro.net/frame.htm because dimension "K" there says 43 7/8 and the one in the 69 fisher body service manual says 42 7/8. So which one is correct? Most all my measurements from the center forward come with in 1/8-1/4" of the dimensions stated in the link or fisher body manual except for "E" "F" and "G". The back measurements are a little squirely. Below are the measurements that are call out for in the manual/link of which "K" is the questonable one. My measurements are in parens () A = 38 1/4" (38 1/8) B = 35 1/4" (35 1/4) C = 54 3/16" (54 1/8) D = 44 9/16" (44 11/16) E = 33 3/4" (34 7/16) F = 76" (75 1/2 right to left) (77 9/16 left tp right) G = 65 1/4" (65 7/8 left side) (65 right side) H = 33 1/2" (33 3/8) I = 55 3/16" (56 left side) (55 right side) J = 66 11/16" (67 1/2 right to left) (66 11/16" left to right) K = 43 7/8 or 42 7/8", WHICH ONE IS CORRECT? (42 13/16) L = 44 7/8" (44 1/16)
I am going to verify the rear measurements again to be safe. I am no expert with this stuff, but if I understand it correctly, by the measurememns that are off, would this show that I have some rear frame issues?
I don't know the answer to K. Doesn't matter too much so don't sweat it for now.
But...F is a serious problem. If you're getting more than 2" difference in a comparative cross measurement, this explains why your rear end is installed crooked and one wheel is sitting forward. That is WAAAAY out of square. Not good. Your G, J and I measurement variations are substantial too, and what you report seems to indicate that this car has some issues with the placement or shape of the rear frame rails. It seems one rear frame rail is a full inch shorter than the other? Possibly wrecked (rear-ended right rear corner most likely....pretty hard, and poorly straightened) or maybe replaced fully or partially due to rust repair and improperly located?
Hate to bear bad news but I'm not very good at sugarcoating things...so my apologies in advance. But your car has some issues here that are not easy to fix. Are you prepared and capable of handling a possible full rear frame rail replacement? If no, you might want to get this car over to a good frame/body shop and get some input from them, see what they feel is bent/misplaced and if maybe it can be straightened or relatively easily repaired somehow.
Unibody/frame repair is sometimes LESS expensive than you think with modern frame pulling equipment. But if someone has already welded on a new rear body panel and quarter panel, while the floor/frame rails were not in the correct position, it may not be possible to repair the unibody without destroying all body lines and gaps in the process.
I believe you'll never get this car to track straight with numbers like that, and it needs some structural repairs.
Thanks Craze, I had a feeling someone might tell me this, but am truthfully glad you did! I know this car has been in a accedint, but I only know of it being hit on the front end because of the reciept for the front end work with subframe replacement. It is obvious that something is wrong and thank god I havent done the frame off restoration which I am going to do SOON! And this will only add to the cost, but I now know something that I must let the body folks know about when I get my estimate for the restro. Thanks, and I do appreciate your honesty as that is what I was looking for. Hopefully, it can all be corrected. Thanks again bud!
Craze, I might add that I took a very good look into the trunk area and up the body line from inside the trunk and I cant see any weld marking inside there that might indicate that a quarter panel has ever been cut out and replaced.
possibly when the were pulling on the front left they only had it anchored on the rt. rear torque box area (rt. ft. leaf spring mount). Done in the days before 4 point anchoring. Not the easiest thing to fix. would definitely explain the axel position.
possibly when the were pulling on the front left they only had it anchored on the rt. rear torque box area (rt. ft. leaf spring mount). Done in the days before 4 point anchoring. Not the easiest thing to fix. would definitely explain the axel position.
Thanks Neill, that might explain things cause it looks like the car was hit before on the front left side as I have an original inner fender on the pass side, but an after market inner fender on the driver side. I dont know when it was repaired for an accident, but PO had body work done back in 92 and front subfram was replaced in 2002
I agree that's a possibility. Or hard left front hit that simply put the unibody into a diamond and drove the whole left side of the car back. This can happen, and was rather common on full frame vehicles like pickup trucks through about teh 1990s...but not so much anymore now that truck frames are stiffer and better engineered. But the type of construction like we have on the Firebirds was long gone before I got into crash repair, so I frankly have no practical experience dealing with accident unibody damage on these types of cars. I would think the main center floor pan would buckle long before the energy would reach the front leafspring mount, but maybe not. Or maybe just poor pulling/anchoring during repair like you said.
In any event, if paying a shop for a full frame resto is the plan, just make sure the shop is well aware of these measurements before they try to do anything else, and if not equipped with their own rack/frame techs that they know a good frame shop the can straighten it. It'll most likely need a pull or two on a rack...half day to a day I'd suspect? And if that takes care of it like I believe it should...$500 or maybe less.
So it's not a total catastrophe and it is fixable, but I believe it's job #1 before doing much of anything else on a body resto. Let the shop decide if it's better to attempt the pull/straightening prior to other disassembly, or after. Who knows what kind of tear-down will be necessary to hook up their pull chains and tie-downs. Might need the whole doghouse off the car if firewall needs to be tugged forward, or if it's just a rear pull that's needed it might be accomplished with only the rear suspension removed and that's it. It's hard to tell much without seeing the car and taking yet more measurements.
Something tells me that if the interior and carpet is fully removed and you know what to look for, good chance you'll see some damage somewhere in the center of the car.
Thanks for the input Craze, I am by no means a body person, but I have been under the car many times, doing the rear end and supension replacement and tranny replacement and havent notice any buckling of the center pan at all, it actually looks pretty good, but I will take another look when I get under there again. Thanks again!
