Hello all, Just want your opinion on suspension. I have a 29 A Tudor. Stock frame, boxed, front extended 10 inches, rear Zed. Front has Split bones with super bell axle. Rear is a 10 bolt with Speedway rear radius rod coil kit. I am a leaf spring guy and can not seem to figure out my issue. -As I drive it feels as if the rear jerks to the side. This causes handeling issues. I hav trouble shooted and touched everything I think. Just haven’t put my finger on the issue. Yes it has a panhard bar and it currently sits a little high at frame but have had other vehicles with more angle and handled better. Any help would be great. Thx
everyone here will want pics of the rear setup as well as the front end setup. Then they will tell you what's wrong.
Had a car with a broken rear axle and it would sort of do the watusi as I drove it. I would start looking at the mounting points on the chassis. Pics are always good. If you have a panhard bar that works it makes it pretty tough for the rear end to move to the side very much. Bushings at any mounting points should also be checked. They might look ok from the outside but might be worn in the middle.
A picture is worth a thousand words and its way easier than typing a thousand words. Sounds like you have an extensively modified frame so there are lots of places to screw up in design and fabrication. Guys on here will look at your front end, wheels & tires (how much air?), shackles, steering and then they will tell you it is not a good idea to run a SuperBell with split radius rods. With the Speedway rear set up and a properly mounted panhard there should not be much wiggle there. You said coils, do you mean coilovers? We'll wait for pictures.
Verify both rear springs are the same rate, also the shocks. One being softer or stiffer than the other could give you action like you describe. The shorter the panhard bar, the more side movement it gives during suspension travel.
You may want to re-check the panhard bushings. Do you have a front panhard bar as well? My roadster was very skittish before I installed one (in the front).
If your panhard bar isn't pretty level at rest then as it cycles through spring compression it can kick your rear ( or even front axle) over to one side causing the car to feel squirlly. A Watts link is really the way to go but it burns up a lot of real estate. Throw up a pic if you can.
You don't need or want a panhard bar with parallel leaf springs. It causes it to bind up with movement. You do need it on the front with split bones.
Hi all and thx for the replies so far. I will post pics as soon as possible. I have run split bones same set up before and never ever needed a front panhard. The centering action of the traverse leaf didn’t allow much side to side movement. But there may be something to it. I will try to simulate side movement. I may need one. -The feeling I am getting it definitely rear. The rear panhard is not perfectly level and again have run vehicles with same angle and never an issue. When I get some time I will fab another longer mount and try it. You never know. Thx
Oh, as for tire pressure I have tried from 19lbs thru 35 lbs all testing this as well. that only changes the ride. Didn’t change the action I feel. And for the coils they are not coil overs.
While this may not cause the issue you’re describing I hate seeing spindles flipped to put the tie rod out front. It throws the Ackerman angle out the window.
I know photo angle can play tricks with what you see verses what's actually going on. That said looking at the photo with the Tires turning Left it looks like your driver side tire is not turned out as far as the Tire on the passenger side. That makes them travel on a different Radi in a turn causing issues for sure. This is very common with Tie Rod out front on an I beam Axle. There are ways to cure that. To test for yourself park on a real smooth Cement floor like your garage. Turn the wheels either side to stop point. Now hold the steering wheel and try to push the car forward 3 feet. What happens?
When you said SuperBell axle of course I jumped to the conclusion it was the tube axle they were famous for. Concerning the Ackerman.... baring distortion in the photo... the tie rod appears longer than the distance between the kingpins, which if you run a string thru the centers it stands a better chance of meeting close to the centerline of the rear end. And of course the inner and outer tires run thru a different radius when turning. So far, so good, if everything that is supposed to be tight is tight and everything that is supposed to move, moves freely. On to the rear.
Only with cross steering and / or a transverse spring that's too long.....with the correct length transverse spring and side delivery steering a panhard bar is not needed or wanted..
Besides the angle of inclination through the king pin to center of the tire that is wrong the shock absorbers could be bottoming out and throwing your steering off. That's a lot of weight to be throwing around with that little front spring JMHO
I will get other pix when I can but found a pic of a temp panhard bar I used. I will put it back in and take some pix soon. But when I did this it helped level the panhard. I may have to fab up another slightly longer and get the bars as level as possible. That is probably it. I got got this car from someone that had a lot of weird stuff done so just trouble shooting. I appreciate all of the input so far.
I am glad you all pushed me a little more about the panhard not being parallel enough. Was in my thoughts just needed a nudge. I did another temporary extension with 2 more inches. Test drive was quick but seemed to improve greatly. I will eventually make a perminante Mount. Thanks All.
I intended to ask if the Super Bell is a tube or I-beam. The tube axle is designed for a 4-bar setup, NOT split 'bones. Even hairpins are a bit forgiving, offering a smidgen of flex yet still not kosher for a street-driven rod.
Maybe your front shackles are hanging a little low. They should be at 45 degrees if possible. Hard to see yours, but I am guessing they are not at 45. Panhard bar if not level can cause some sideways movement. Even on some factory cars I have driven with a panhard bar in certain situations you could feel the sideways push.
Firstly I'd check that the frame is square and measure lengths on both sides as well as diagonals. I'd then check that both front and rear axles are square in the frame and centred side to side. Next check diagonals of both axles and wheelbase, note any discrepancies between measurements. Lengths should be the same side to side; diagonal measurements should also be the same from side to side. Suspension works better in parallelograms or triangulated. Pictures are worth a thousand words! Steering arms, shackles, axles not centred, staggered wheelbase with offset axles; could be a plethora of issues and not one single issue.