Aaarghhh! Suspension woes, '41 Bodge

[Wiggo]

Me again, with the 1941 D20. I mentioned earlier that the rear springs are shot, and counting the leaves a few minutes ago, they are not stock anyway - 8 leaves, not the 7 or 9 that the manual suggests for a P11 or P12 for that year. Anyway, whatever.

 

So the front was sitting oddly, too. With the car up on the lift, it was obvious that one front wheel hung lower than the other, and someone had fabricated their own shock top mounts to the frame rails. No idea if they're even or not, bu that can wait. But now we noticed that the car sits crooked on the ground. The right front wheel has more than an inch of extra clearance between the top of the tyre and the wheelarch than the left, but also the lowest point of the frame on the left is closer to the road, too. A rough measurement with a tape measure says the distance between the upper and lower control arm pins is different - about ¼" or more. That tells me the steering knuckle support rods are different lengths.

 

Any ideas what is going on here? I obviously have a Frankenstein front suspension, but what vehicle might the other steering knuckle support be from? And how do I tell which side is right?

Edited March 28, 2018 by Wiggo

[Plymouthy Adams]

first off I think you reporting that the body is sagging due to weak suspension components....not so much wrong mismatched components.  If one spring is weaker than the other....you got sag.  Often the drivers side due to the fact there is always a driver sags more than the other.  You could have a spring rate difference on the coils but only taking these apart to inspect the stamped number can confirm matching set.  The odds that the upper and lower A-arms, uprights etc being mismatch is a possibility but you can confirm these with a good tape.  If shock were relocated, are the shock installed proper operating parameter collapsed/extended, equally set left and right.  Again...springs rates and shocks will wear and vary with age.

[Wiggo]

OK, understood. The shocks are brand new, but the springs are of an unknown vintage and someone has already cut them down, so I agree there are a lot of variables here.however, if we swap the springs from one side to the other, nothing changes in terms of ride height. In summary, however, with the car on the ground:

• The top of the right front wheel is about an inch closer to the lowest part of the wheelarch that the left
• The lowest part of the left front chassis rail behind the K member is an inch closer to the ground than on the right.

I'm getting confused again, so I'm making up a drawing...

[Young Ed]

didn't they also make the cars slightly off level to compensate for the crown of the road?

[Wiggo]

If so, I'm screwed because we drive on the left here...

 

Anyway, I think I got this right (looking at the car from in front), but now I'm wondering if this isn't just because the left rear leaf spring has sagged badly, meaning the right rear is pushing the left front of the car down...

 

 

 

Actually, thinking about it, wouldn't different camber settings on the upper control arm pins' eccentric nuts account for the apparent difference in support arm length?

Edited March 28, 2018 by Wiggo

[Plymouthy Adams]

yes, the rear suspension if whacked even with low tire pressure will have an effect on the standing position of your front suspension....

[Plymouthy Adams]

am in the shop doing a bit of cleaning and sorting of materials on hand...I pulled the set of uprights out of the box that just happened to be sitting on the counter and as a goodwill gesture to let you know the center to center measurements of both left and right are 10.5 inch....in your drawing above, with the suspension assembled...your measurements are as stated approx. due to the eccentric positions.  A back to basics to set up your suspension seems to be warranted at this time.

[DJ194950]

Possibly the frame is twisted?

Long shot, but measurements could tell you or sure with suspension parts out of the equation if frame to leveled side to side and front to back on a good flat surface. ??

 

DJ

[Jerry Roberts]

Are your two front tires the same size ? If in doubt , switch them from side to side and measure again . 

[brian b]

I agree with dj194950, you could have a bent frame.  Your front fenders could also be out of alignment, giving you the  different  distances from tires to fenders.  My 39 business coupe fenders are a little lopsided, and the left fender is slightly different from the right.  Left is off a car, right was nos with a factory tag, spent its life up on end and settled a bit.

You need to get the car on a level floor and jack up the frame and get it level with the floor, at least at the jacking points, as the frame isn't perfectly straight like a model A.  Then start checking if your body is straight, or your frame is bent.  Bad body mounts will also sag the body.   If you have trouble getting the frame level, or one corner seems higher or lower, you found your first problem.   Take your time, measure carefully, think nice thoughts .  You'll figure it out.

 

                                                                                                                                               brian b

 

[Wiggo]

1 hour ago, Plymouthy Adams said:

am in the shop doing a bit of cleaning and sorting of materials on hand...I pulled the set of uprights out of the box that just happened to be sitting on the counter and as a goodwill gesture to let you know the center to center measurements of both left and right are 10.5 inch....in your drawing above, with the suspension assembled...your measurements are as stated approx. due to the eccentric positions.  A back to basics to set up your suspension seems to be warranted at this time.

Wow, thank you so much for that info! That is a massive help. First step will be to set the rear of the frame on axle stands, to eliminate the rear springs. My guess is that the front will sit more or less level. Any difference (I hope) will be down to the camber being screwed on one side. If so, back to basics it is!

[knuckleharley]

2 hours ago, DJ194950 said:

Possibly the frame is twisted?

Long shot, but measurements could tell you or sure with suspension parts out of the equation if frame to leveled side to side and front to back on a good flat surface. ??

 

DJ

That was my first thought,also. Before you go spending a lot of money on expensive repair parts,you need to take your car to a frame shop and find if if the frame is square.

[Wiggo]

OK, so thanks again for all the thoughts and ideas. This morning, we remeasured everything (I had the original drawing back to front) with the car on the ground, then jacked the rear up and rested it with the rear tires just clear of the floor. The results are as shown here:

 

 

So it seems the front is OK, more or less. The difference in the length of the front uprights is explained perfectly by the camber eccentrics, so thanks to Plymouthy Adams for that one. The rear springs are way out of whack, with the right spring being much stronger than the left one. Oddly, this has caused the right spring to kick out to one side, and actually lowered that corner as shown...

 

 

Edited March 29, 2018 by Wiggo

[Frank Elder]

Wonderful pictures and explanation, you should print those out and hang them in the garage for future reference.

[Adam H P15 D30]

Posies makes Super Slide rear leafs for our cars.  I believe both stock height and lowered.  Might as well get a better ride too....

 

Adam

[Wiggo]

4 hours ago, Frank Elder said:

Wonderful pictures and explanation, you should print those out and hang them in the garage for future reference.

 

Thanks, the final one to explain the odd ride height. The final image has one upright ¼" shorter than the other, which compresses the spring slightly and probably lowers that corner by ½" or so.

 

[Frank Elder]

I see bug eyes, cross eyes. rolled eyes and wall eye.......lol.

[Wiggo]

22 minutes ago, Frank Elder said:

I see bug eyes, cross eyes. rolled eyes and wall eye.......lol.

 

You were obviously watching me trying to work out what was wrong ;-)