So what I have is a 1959 Chevy pickup with the stock frame. I took the stock axles out and replaced them with front and rear out of a dually dodge motorhome. I believe 70's. I used leaves, mounts, everything without a sway bar. I have it all bolted up and driveable. The leaf packs in front have 8 leaves and rear has 6 leaves from the motor home so you can imagine the rough ride being a much lighter truck. I have shocks in the rear and shocks for the front ordered, but not installed. Now, the problem. When driving id guess 15-20 mph the truck will sometimes get a "bounce" the left and right tires bouncing up and down one at a time. Almost like the frame twisting back and forth as well. I dont feel a pull side to side though. Some reading online has said shocks fix the wobble but im not convinced thatll fix my problem. The suspension being to tight and stiff? Any thoughts would be appreciated! Posted using the Full Custom H.A.M.B. App!
add Shocks,then most likely you should remove some leafs out of spring pacs. tire psi maybe should be lower
Shocks will fix that. Bad or no shocks will take a normally small unnotacible shimy or bounce and amplify it. Think of a basketball bouncing, now think of that same ball trying to bounce under water. That's what the shock does.
Exactly. Read up on the Natural Frequency of a system. You are probably hitting the natural frequency between 15 and 20 mph, hence the amplified bounce. Shocks reduce the amplification that occurs when a system is excited at it's natural frequency.
same here. ive tried to explain skocks to a kid here at the shop not to long ago.this would have been dead on had I thought of it.hell its perfect!lol
It's often called "death wobble" and shocks should fix it unless you have worn bushings or screwed up steering geometry. I had it on my new 4x4 truck and adding positive caster fixed it.
Well sounds pretty unanimous that I need shocks. Ill make some mounts and put them in the see what happens! Thanks all! Its just a stock rebuilt 305 with a 350 turbo trans. Nothing fancy at the moment. Sort of a money saver at the moment. The intent is to put a motor and trans that fits more with the big heavy duty truck, you know. Posted using the Full Custom H.A.M.B. App!
my friend has a 57 mounted on a 69 ih 1600 fram and it dosent have shocks but it has weight a 5.9 cummins with a 4speed main box a 3speed brownlite with a 2 speed rearend a steel flatbed with 15 ton winch and a wrecker pole
All vehicles require shock absorbers, on all four corners. It is never okay to run without them. Running without them could result in catastrophic loss of control of the vehicle, with little or no warning. You could easily get yourself, or someone else killed.
Well got some shocks installed and tire pressures all set to 35. Test drove it. It felt better but it still had the shake/ bounce back and forth between tires and up and down. What next? Im thinking taking some leafs out. Should I start with the bottom smaller leafs? Any other thoughts?? I do appreciate it all. Posted using the Full Custom H.A.M.B. App!
I had a walk-in van that had bent wheels. It did the same thing. When they were put on a spin balance machine the were prob. about 1/2 inch runout. The guy used to hop curbs to deliver at mom and pop stores.
There definitely could be other things wrong like your toe in/out, caster angle (may need shims between axle and springs to correct that). Have you taken it to an alignment shop? Balance the tires also. Im wondering if you are getting some lateral movement of the springs with the rear spring hanger dropped down from the frame as you have it. I would think the lateral movement along with improper alignment could also cause your condition. Also have you checked the front bearings for wear and proper installation? If you have a lot of free play in your steering box that could also be a culprit.
I bought the axles and made mounts and everything myself. I measured everything to get it evenly spaced and straight. Posted using the Full Custom H.A.M.B. App!
I'm not sure how the normal suspension mounts to the frame but if you lifted the body of the truck and did not change the steering you in essence shortened the angles of the steering. I can't really tell from that pic but you might need a dropped pitman arm to realign things. If it has a steering stabilizer on there also check that. I really have no idea how that steering works so i might just be babbling.
I thought about the axle being bolted so far from frame could cause some problems. I took front tires to have balance and the guy told me I wouldnt feel it around low speeds. Only around 55. I do know I need an alignment or at least have it checked. I didnt think that'd cause a shake. I thought alignment would be a pull. Posted using the Full Custom H.A.M.B. App!
I dont know how the mounts were either. When I bought the axles the guy had them pulled from the motor home. I called him when I got home to get specifics on what type of motorhome and he never answered or called back. I did install axles and then designed steering components after truck was lifted. Not saying I dont need a drop pitman just saying I designed it afterwards. No steering stabilizer. Should I have one? Not sure what purpose is for them. Posted using the Full Custom H.A.M.B. App!
Usually an alignment checks caster, camber and toe. If you have to much toe in or out it causes tire scrubbing and the tires will fight each other to try and go straight which could cause a vibration. Caster angle helps with getting the wheels to self center out of a turn or just staying centered driving straight down the road.
So if there fighting could it cause them to bounce back and forth up and down one at a time? Posted using the Full Custom H.A.M.B. App!
Well it isnt going to hurt me to get the alignment checked. Ill give that a shot on Monday. Thanks! Posted using the Full Custom H.A.M.B. App!
I bought the axles and made mounts and everything myself. I measured everything to get it evenly spaced and straight. Posted using the Full Custom H.A.M.B. App!
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