Well I drove to the alignment shop, and he put the 56 with all new/rebuilt front suspension on the fancy computerized/laser-guided machine, and ... cannot get anywhere close to the factory specified 1 degree postive caster, and cannot get any positive camber either (toe-in of course is not a problem). Reason: very little adjustment built into these early cars, and I have dropped the front end 2 inches and raised the rear end about 4 inches, introducing over 3 degrees of negative caster into the front end.
Steering is OK driving down the road, turns really easily, BUT the return-to-center feature we are all accustomed to is gone - I have to crank it back to straight. So I have 3 choices:
1. Live with it. Drives OK except for the missing return-to-center feature which is kind of weird. But it does drive OK, no wandering, no pull, no twitching.
2. Buy a pair of tubular upper control arms that have 6 degrees more positive caster and 2 degrees more positive camber built into them. (They do this by relocating the upper ball joint towards the rear of the car and out a little bit too.) Easy bolt-in, cost about $350. Ouch, not really in the budget but you know how it goes. I would be wasting the parts (bushings and ball joints) and labor (to press the bushings out and in) I have in the original upper control arms, could put them on the shelf, maybe use them for some later project ...
The alignment guy can easily add shims to bring the caster and camber into line with specs with those control arms.
I am not a big fan of tubular control arms, they do not fit the type of car I am building, but I could live with them.
3. Fabtricate my own upper control arms. I have a spare pair of uppers that I picked up a while back. The bushings and balljoints in them are junk. And they need sandblasting or other cleanup for surface rust. But these are not a problem at all, for what I have in mind.
What I could do is cut both arms sort of in half, but in such a way that when you welded the pieces back together, the the upper ball joint would be moved towards the rear of the car and out a little bit too - giving you positive caster and camber. I have done the trigonometry (and here you thought nobody would ever use trig, eh?) and 1 inch to the back and 1/4 inch outward would be just right.
Here is how I would cut the pieces:
- This shows the two donor control arms, one laid on top of the other, one with the bushed shaft correct for bolting to the car, the other with the ball joint in the corrected location - you can see where the width of the 2 arms is the same so they could be welded together with minimal gaps:
- The spare control arms would be cut as shown here:
- And this is the part that would be used:
- The rebuilt control arms that are in the car now would be the donor for "Part b" because the bushings are brand new. I would also take the brand new ball joint off them and put the ball joints on "Part a" from the spare control arms. Here's the cut:
- And here's the part that would be used:
- End result:
I would have to farm out the fabrication, because I am not a good welder. I would do the "where to cut" on each of the donor control arms, because I *AM* a good mathematician and can make accurate measurements (I would probably fabricate a jig out of wood to ensure the balljoint would be moved the correct amout).
I would not grind the welds to keep the strength, so they would not be pretty, and with the angle being very obvious, they might look weird. But they would allow alignment to be done according to factory specifications.
What do you think?
Dave
P.S. if anybody wants to see the trigonometry calculations, just let me know.
-- Edited by davelacourse on Friday 23rd of October 2009 12:29:10 PM
-- Edited by davelacourse on Friday 23rd of October 2009 12:33:33 PM
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
Was the alignment (at least the caster) on a 56 not done entirely with shims anyway?
Shim in as much positive as you can get...find another set of arms on top of your spares, and start on your geometry project. Drive the car while you take your time working on the new arms.
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65 Laurentian post, 67 Grande Parisienne 4 door HT.
Yes shims alone for caster and camber adjustment, they have been tweaked as much as possible, still a lot of negative caster and no camber. (Toe is set by adjusting tie rods.)
The alignment guy said "Just lower the rear" and I said "That is not an option" since I like the stance and also it's the only way those big tires will fit in there without cutting the wheel opening in the rear fenders (and I like the factory lines).
Thanks, Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
Well I drove to the alignment shop, and he put the 56 with all new/rebuilt front suspension on the fancy computerized/laser-guided machine, and ... cannot get anywhere close to the factory specified 1 degree postive caster, and cannot get any positive camber either (toe-in of course is not a problem). Reason: very little adjustment built into these early cars, and I have dropped the front end 2 inches and raised the rear end about 4 inches, introducing over 3 degrees of negative caster into the front end.
Steering is OK driving down the road, turns really easily, BUT the return-to-center feature we are all accustomed to is gone - I have to crank it back to straight. So I have 3 choices:
1. Live with it. Drives OK except for the missing return-to-center feature which is kind of weird. But it does drive OK, no wandering, no pull, no twitching.
2. Buy a pair of tubular upper control arms Easy bolt-in, cost about $350. Ouch The alignment guy can easily add shims to bring the caster and camber into line with specs with those control arms.
I am not a big fan of tubular control , but I could live with them.
Buy the tubular ones LATER you can't make them for less than 350.00 Its a Hot Rod not a show car... tubular are cool and professionaly built
Had a similar problem with a 61 Pontiac Tempest wagon I built a couple years back. Altered the upper control arms, relocated ball joint [Used Chrysler screw-in style] was a massive pain in the ass. In the end I went over to McColls racing products [London] and got off the shelf uppers [Cascar Tubular] and was done with it. It turns your problem into a no-brainer!!
HMMM, Unless it really bothers you to have to "return" the steering to centre , everytime you make a corner, I'd leave it as is...Maybe purchase the tubular ones later on, if you feel nessesary
My 2 cents
Ken
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1960 Pontiac Strato Chief Safari 1960 Laurentian Safari 1960 Laurentian 4door(scrapped) 2001 Grand Am Traded on a '96 Suburban 2WD 2002 Hyundai Accent(SOLD) 1968 Grand Parisienne Scrapped and SOLD
Thanks for all the input, guys - I decided that I wanted the alignment done right, so even though I could live with it, I will change the upper control arms. And I decided to go with powder coated tubular upper arms from Eckler's - their Halloween sale was 15% off so I got them for $305 US, they have 5 degrees positive caster (mine is now 4 degrees on one side and 4 degrees on the other side, both negative caster - so adding 5 will allow both to be shimmed to the specified 1 degree positive), 2 degrees postive camber (mine is now a tenth or two negative, so this will allow shimming to the specified 1/2 degree positive).
Thanks again, I did take into account everything everybody said.
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
an old rodders trick on the 55- 57 is to cut the welds on the rear side of the mount for the upper, then tap them up against the frame rail and re weld. This corrects the castor. If you look at the last picture , you can see how this would work. I got this tip from a friend who ran an alignment shop for years, and drives, races, breaths 55 chevy's.
sorry for coming to the party late !!
The tubular looks real cool , nice and clean !!
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later...rog
AADD supporting member !!
I'm a collector...not a builder!!Located in sunny central Saskatchewan at the lakehead!
great, now you have me really worried!! I just dropped the whole car about 3 inches all around, and from what i have read i knew it would mess with the car a bit, probally go through tires faster, and might not handle as well, but is it dangerous?? I have not driven the car yet so im not sure how it handles. I just figured i would have to watch for potholes and big bumps!
great, now you have me really worried!! I just dropped the whole car about 3 inches all around, and from what i have read i knew it would mess with the car a bit, probally go through tires faster, and might not handle as well, but is it dangerous?? I have not driven the car yet so im not sure how it handles. I just figured i would have to watch for potholes and big bumps!
The main reason I had a problem with front end alignment is that I changed the rake of my car substantially. The calculation is as follows (and here you thought trigonometry would never be useful in the real world, eh?):
The wheelbase of a 1956 Canadian Pontiac is 115 inches. For every inch of rake (done by either raising the rear end or lowering the front end, or both in combination) the caster changes by the tangent of 1/115 = 0.5 degrees. In my case, I lowered the front 2 inches and raised the rear 4 inches so I added 6 X 0.5 = 3 degrees of negative caster. Hence my need to make some other major change to get alignment within spec, since there was not enough range of adjustment built into the car by the factory.
Since I used stock height front springs (the front end lowering came via dropped spindles) there should have been no other changes in geometry that affected my allignment.
In your case, you lowered both ends equally, so you did not change the rake, so you will not have the same problem I did.
Good news eh?
However, you still should consider the following.
Given no rake change, the only impact lowering the rear on a solid axle car like yours should have is (1) less suspension travel over bumps (as you know) and (2) in theory, slightly better cornering at speed since you have lowered the center of gravity. Maybe a somewhat harsher ride, too, since coil springs are designed to operate with a given length.
In the front, you should have the same as above, plus whatever changes in geometry resulted from the drop - my guess is that you would have significant change in camber (because most independent front suspensions are designed to have camber change during cornering when one wheel will drop and the other rise due to weight transfter), which is not good - for sure front tires will wear out fast (unequal wear) and handling will be adversely affected. Take the car to an alignment shop (if you are like me and do not have the [expensive] tools to do it yourself) and find out. Hopefully the alignment shop can shim enough to get your car in spec so you will not have those problems. Otherwise you will have the same dilemma I did - live with it or fix it somehow. I do not know enough about the 59 Chevy chassis to know about possible fixes.
You probably have introduced a change in caster when you dropped the front, since you have changed the static location of the lower ball joint compared to the upper ball joint. I don't know the geometry and measurements for a 1959 front end (similar desingn but not interchangeable parts compared to 1956) so I can't do the trigonometry again to find out - but the same trip to the alignment shop will give the answer.
Good luck Trevor!
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
thanks dave, math was not my strong subject plus i dont really know how everything works as far as the suspension camber, toe in, and all that stuff. Reading this post and what you were saying made it a little clearer though, thanks. After march the cars going in to tinys for the alignment. I love the rake on your car, looks awesome.
thanks dave, math was not my strong subject plus i dont really know how everything works as far as the suspension camber, toe in, and all that stuff. Reading this post and what you were saying made it a little clearer though, thanks. After march the cars going in to tinys for the alignment. I love the rake on your car, looks awesome.
And the 3 inch lowering job on your 59 looks great!!!!
If shims won't get the job done now on your front end with the cut coils, maybe do the best you can and then when you have the cash to do the dropped spindles (and new stock springs) do the alignment again, is what I would suggest. And put cheap used tires on the front until then
I would also suggest that you go to power disc front brakes when you do the spindles - you can get spindles specifically designed for the calipers without extra brackets, and disc fronts plus the power booster make for WAY better stopping - the improvement on my 56 was amazing. When the time comes, let me know, I can fill you in on where I got mine (direct from manufacturer, complete kit including all the bolts/hoses/dust caps, no extra trips to the parts store).
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
sounds good. When i was looking at the droped spindles i figured i would get the disc brakes as well. When i sold my trans am i kept the brake booster so i could use that, i was actually thinking ahead for a change!!
Dave, good choice on tubular arms, I think the re worked ones would have worked, but in the back of my mind I'd be worried all the time "is this going to break" I also "love " the RAKE look!!!
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Some times I wake up GRUMPY, but today I let her sleep in !!!!!!!!BLACKSTOCK Ont.
Hey Trevor the 59 looks soooo neat lowered and the brake upgrade is probably one of the best mods you can do. That car is a heavy weight and discs will give you way better performance and safety. The suspension geometry has changed when lowered and Tiny is the man to make it right.
its going to tiny for sure, same with my PT Loser, needs some front end work as well. With the car lowered it looks more hot rod/custom, which is what im going for, cant afford an original looking resto, plus thats not really me. is the T/A ready for the summer? You have to take me for a spin, i miss mine a bit, that part when you let the foul barrel open and get pushed back in the seats is what i miss the most. The 59 is a slow and now low rider!
Well Trevor i had a camshaft let go ,1 lobe and lifter ground to dust. This happened the last week in August and i was to say very ticked. The motor has been out for 3 months and i stripped it down (bare block) and it is at a machine shop. I decided to go with a complete rotating assembly from British Columbia , company is called SD Performance. I am going all in with a stroker kit ,this will take me to 464 cubes. The owner Dave Bisshop is a very well known pontiac engine guy and we talked for a long time about the parts industry and the problems camshaft makers are having. I have decided to go with a full roller cam and this also has made me get into full roller rockers and diffferent springs. I am getting everything shipped this week and hope to get the parts to the shop friday. The motor is going to be a monster torque producer and i cant wait to fire this thing up down the road. I will for sure give you a ride when its done.
1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
