|01-24-2013 05:36 PM|
|39 chev||I have installed 3 stock mustang crossmembers in early chevy's.2 in 39's and 1 in a 38.I heated and dimpled the frame rails where the control arms hit the frame rail. a little heat and a couple of blows with a large ball pein hammer did the job. looks like it came that way. I did my 39 about 25 years ago and the others a few years later. I retired from the frame and front end business after 39 years,so I know what works,but I don't argue with the engineers.|
|01-23-2013 09:06 PM|
Sorry for so long to provide an update. Had car in Cavalcade of Customs and wife had surgery so not much time in the garage. I finally got the front wheels off and it was obvious that the problem is that the cross member when welded into the frame was too low to allow proper adjustment of the rear of the upper control arm shaft. These photos show the amount that the control arm shaft is cocked to get the camber adjusted and it causes the caster to be off. You can see the adjustment slot in the front and the slot is covered with the cross shaft in the rear. The lower A Arms are level across the car and are in the center of the cross member. It does not look like the lower arms are out of position.
I really didn't want to cut the cross member out and start over as I would probably have to pull engine etc. In looking at alternatives, I found that tubular upper A Arms have much smaller diameter housings for the bushings. The stock A Arm flange has a radius of around 1.25" where it is hitting the frame. The tubular A Arm has a radius of .800". The height of the frame to the centerline of the cross shaft is around .750".
New Tubular A Arms arrived today and my plan is to tear apart the front end, put new bushings etc in existing lower support arm, and make a small recess in the frame to clear the A Arm when it is at the inside end of the adjustment slot. I will weld in additional steel to make certain the new recess does not affect strength of the frame, it won't take much of a recess compared to what would be needed for the stock A Arms. I estimated that to use the stock A Arms would require a recess of a minimum of .75" while the tubular A Arms will only require about .25" depth and much less in length across the top of frame section.
I will give an update when I get it all done, will take my time to make it all look good as well. Thanks again for everyones help in getting this thing sorted out.
|12-04-2012 08:02 PM|
I really appreciate all the effort everyone has put into this situation. My ability to get time to work on it has been put on hold due to my wife just having surgery.
I was able to get the before and after print out of the readings. Camber before was 1.3 on left and -1.3 on right. Caster before was -1.1 on left and -5.3 on right. Toe was -0.17 on left and -0.04 on right. SAI was 9.1 on left and 12.2 on right. Included angle was 10.4 on left and 10.8 on right.
Front readings before were as follows. Cross Camber was 2.6, Cross Caster was 4.1, Cross SAI was -3.0.
Rear Readings before are - Camber -0.3 left and 0.1 right. Toe was 1.30 left and -.069 right.
Rear Readings before were Cross Camber -0.3, Total Toe 0.61 and Thrust Angle was 0.99.
I have had the car out and driven it and it really doesn't seem to have any 'bad habits'. It tracks straight and doesn't pull. Doesn't seem to oversteer when turning. The power steering may be masking effort.
The Actual Final Readings per the print out are as follows:
Camber 0.2 Left and 0.4 Right, Caster -3.2 Left and -3.5 right. Toe 0.02 Left and 0.05 Right. SAI 10.1 Left and 19.1 Right. Included Angle 10.2 Left and 19.5 Right.
Front Final Readings were Cross Camber -0.3, Cross Caster 0.2, Cross SAI -9.0, Total Toe 0.06.
Rear Final Readings were Camber -0.5 Left and 0.2 Right, Toe 0.34 Left and 0.26 Right.
Rear Cross Camber -0.7 Total Toe 0.60 and Trust Angle 0.04.
I still intend to pull the wheels and take measurements and more pictures. It may be awhile before I can get the time to do it.
Thanks again to all who have spent so much time on this. I will post more information as I get to it
|12-04-2012 10:48 AM|
I would be willing to bet it was read wrong..
I would go back to the way it should have be done in the first place..Do it yourself.. You will come just as close..I can't remember the last time I let someone do mine..Get a good protractor/angle finder, And go to town... I have seen a lot of people go get it done on a machine and was worst off then they went in with..
|12-04-2012 09:57 AM|
I just went and looked up the stock Mustang II specs, it only calls for .75 degree positive caster!
|12-04-2012 09:46 AM|
It's tough with things are off this far. I know in repairing collision damage there is NO WAY we would attempt to "align" out something this far, wouldn't even be tried, there is something seriously wrong with structure or components. That SAI is so far off I also have to wonder if it wasn't read wrong with the machine, that is REALLY a mile off. It says bent spindle when the SAI is that far off and the camber is the same, there is really nothing else it could be. However, never saw anything like it, 9 degrees, holy cow, we are usually talking a three or four max.
Unk, just going back to a real basic idea here, how far is the tire/wheel from the upper ball joint/control arm side to side. For that SAI to read as it does there would have to be a BIG difference side to side.
|12-04-2012 05:40 AM|
The question now would be if the crosmember is canted foreward at the wrong angle, using the shorter arms and possibly longer slots moving the upper ball joint back to get the spindle at the right castor and camber angle MIGHT have the bottom ball joint binding, or too far out of the optimum operating angles. time for more measurements. mabe removing the springs and shocks. move the spindle up and down , checking, that and see if the tie rod to rack angles change enough to induce some bump steer, the 'Fox mustang racers use spacers to move the tie rod for autocross handling.
|12-03-2012 09:41 PM|
|12-03-2012 09:21 PM|
You can go the heidt's website and check out their installation instructions. A few years ago when Gary was in charge he had a lot of Mustang II engineering info on the site..If you down load their New catalog read pages 67 thru 69 most of the old stuff is there,
|12-03-2012 04:44 PM|
By the way Unk, you can also put a protractor/angle finder on the upper control arm shafts. That can help you find one more piece of the puzzle. If you had a stock Mustang to match it to, that would also be interesting.
|12-03-2012 01:47 PM|
But we still have the SAI off 9 degrees! I honestly can't see how that is even possible! Something is really goofed up here.
And those upper control arms would have to move a LOT, it has to go 4 or 5 degrees on the caster!
|12-03-2012 01:21 PM|
after looking at the pics of his upper arms and where they are hitting the frame
why couldn't the arms the just be ground down/trimmed where they are hitting?
|12-03-2012 12:54 PM|
would just using tube type arms like these, give him enough clearance at the frame, to make the needed adjustments?
or maybe some narrowed upper arms like these shoved out to make room?
|12-03-2012 06:58 AM|
A guy I used to work with road raced his pinto, I think some of the guys in his class custom built tubular Upper A arms, 1 in DOM, chrysler screw ball joint sockets They were more of a wide U instead of an A shape. It might be easier for the new owner to Buy a new bolt in crosmember, cut out the stock one and use His pieces, The Mustang II stock crowmember probably should have been notched to get it the right level position, It looks like the spring pockets are still factory welded. My son still has the pieces to put a stock crosmember under his 36 plymouth coupe. He looked at a car last summer at a car show and said the guy had built a couple wedges to go between the stock crosmember and the frame to get IT Right. The chevy front frame rails are fairley straight, the ply dodge cars hump up the frame . If the original builder just C clamped the stock crosmember to the frame everything started wrong. Frame should have been at ride height and rake. then the crosmember adjusted by notching or wedging make everything plumb, level, square, take it apart and grind or sand blast the crosmember weld area both sides inside and outside of the weld area, hospital clean, I have seen stuff welded where the other side of the metal was coated with grease and crud, hard to get a good weld welding in greasy mud contaminating everything, . tack, recheck, tack recheck.
|12-01-2012 09:57 PM|
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