can anyone tell me what angle there running there rear shocks? its for a 31 coupe, and im using 37' lower shock mounts that bolt to the backing plate. but since im running a wide 46' truck rear end it putting the shocks at about 20 degrees. and it seems like there binding up. any idea..please help
I think 20 degrees is a little too much angle. I'd say ten degrees at the most. I'll be interested in seeing what others have to say to this good question.
20 degrees from vertical should not be a problem. If you have a bind,I'd be looking at something besides the angle. Could be an alignment issue in the mounts,could be a bent shock, could be a bind in the suspension.Are you running split 'bones on the back ?
yeah i am running ladder bars in the back made out of early 40's radius rods. i thought that the binding might have been coming from somewhere else. but i took the shocks of completely and the rear spring travels up and down very nicely? . they are old shocks, but they dont seem to have any leaks and are nice and tight, would you recomend getting new ones?
due to the angle i would try to get some heavy duty shocks with stiffer valveing . Check to make sure the mounts are even top to bottom. if they are ****ed it will cause some binding.
What do you mean when you say your shock binds up? To address this question you will have to explain at what point the suspension binds up. You should have no trouble with 20* angle of your shocks however this is about the maximum angle for efficency. If you have mounted your shocks using the cast brackets with a shock spud that bolts to the backing plate bolts correctly they will only act as a spring damper. If your ladder bar setup swings freely with out the shocks hooked up and you experience no bind, the installation is ok. The slight arc that the axle rotates on during compression and rebound is taken up by the rubber bushings in the shock absorber. Body roll should be checked to insure that the angle of the shock does not position the shock to hit the frame or rub on the tire. With 20* angle it is pretty sure that this is not going to happen. The shocks can be easily hand checked by collapsing them and extending them fully back out to check for soft or hard spots in operation. This can also determine if the shock is in adequate condtion by comparing the resistance necessary to open or close the shock. Since most shocks are 50/50 or 60 rebound 40 compression you should experience about the same feel when bench testing each unit. The only other potential for binding up would relate to the extention of the shocks.At ride height the shock should be at approximately 50% of travel up or down. Check to ensure that they are not bottoming or topping out due to incorrect travel installation. ****
nope..no torque tube..its a 46' open truck rear. ive checked all my angles and the shocks are perfectly even, top and bottom and have about 15 degrees of angle on them..and without them on, the rear end moves very freely up and down. but once i hook the shocks up its so stiff it doesnt even really move when im on top of the rear crossmember jumping on it. Is it normal for it to be that stiff.
Drop the axle to it's lowest position, without the shocks on, then fit them in place. They go on okay with no hammering? Right, remove them and bring your axle to it highest ride position. Try to fit the shocks on again. Do they go on easy enough? See if the bushes are all out of line, if the shocks won't slip into place. If they shock goes on easy in both positions then try it half way up. If it still seems to slip into place easy enough then it must be the internals of your shocks. it can be nothing else. Are you sure you have enough flex in the bushes to allow for the rotation of the axle due to the ladder bars? Are your bushings spaced internally (compression tube) so you are not tightening down onto the mounting brackets?
I've read all the posts on this and I have a question? Are you calling shock absorbers, really coil over shocks? If you have coil overs you kind of left out some important information. And yes it is possible to appear very stiff with coil overs the next question is what kind and what is the spring rate?
****, definitly not running coil overs. its an original A frame z'd 10".. with the rear end hung from an A spring, im using 37' lower shock mounts in the back.
Well, that clarifies that. Next, start by unhooking your spring and allowing the rear to raise and lower produces no bid , correct? Hook up the spring with no shocks, if there is no body on the ch***is and you try to jack up the rear end the suspension should only move about 1" before the ch***is lifts. Set the ch***is back down and stand on the ch***is, your weight should only compress ch***is about 1". Now take the shocks and compress and extend by hand they should work smoothly. Put the shocks in place and again stand on the ch***is, ch***is should compress same as with out shocks. It is the appearance that the ch***is is rigid but in reality is not. The suspension is to support the weight of the vehicle and if you only weigh 150 just by standing on it is not going to show much deflection. If you had and exceptional amount of spring travel with just your weight you are vastly under sprung. Since your rearend travels without a bind it is highly unlikely that there is a bind in the shocks. The only other scenarios would be that you have the shock mounting bolts tightened so tight that it does not allow the shock to pivot or that you have the eyes of the shock at 90* to each end. While this does not necessarily produce a shock bind it can put stress on the eye during travel and cause the end weld to crack.
sounds good. im not sure of the exact year of the shocks im using. were there different shocks for p***enger cars and trucks? could these be truck shocks, and more stiff because of that? thanks a lot mike
If you're using the old lever shocks and not tube shocks, you need to post some pictures of the installation, before doing another "50 questions" on this. If they're tube shoucks they are whatever make got installed last time the source vehicle went in for a lube job and the owner got sold new shocks.
there not lever arm shocks...there tube shocks..and i dont know what vehicle they came off of. But im taking ****'s advise and hopefully they will work fine thanks mike
If the original shocks were standing straight up and down and are now angled, are you sure your shock mounting brackets are allowing the shock to travel at the needed angle? If the shock mounting brackets were designed for the shock to remain straight up and down through out the shock travel and you are now trying to force the shock to one side, you will get a bind, esspecially if the angle of the shock angle increases as the shock compresses. The bind would be much worse if the shock mounting brackets were built with the intension of the shock angling forward and backward throught out the shocks travel but you are now trying to angle the shock outward. The shock brackets have to be designed so the shocks can work at the angle they need to travel or they will bind. 15 degrees is asking for a lot of give in the rubber bushings, and that angle probably grows as the shocks compress. If the shocks can not opperate at the angle they need to, down the road they will break the mounting brackets. I know, been there, done that. Gene
Pull the shocks off. Can you move them by hand ? I had some that looked brand new,but seemed to have siezed solid. Or maybe you got a nice set for a Dump Truck. The eyes on the ends of the shocks should be parallel when mounted. Pictures might help.
I think you're missing something very basic here, like you can't push the rear end down because it has a ****** great spring holding it up??? Have you tried like I suggested; simply move the rear end top to bottom and try to fit the shocks in each position?? WITH THE SPRING OFF! It's hardly rocket science, yet you're still baffled by a problem that should stick out like dogs balls by now.
Do you have the body mounted on the ch***is. If you only have a naked ch***is mounted and have installed the shocks, it will be stiffer than Hell.---its supposed to be that way.
im going to work on the car tommorow, so im gonna try everything everybodys suggested and let you know how i make out. thanks again mike
Also one thing to look at is the position of the shocks to the rearend......if both shocks are in frount of the axle it pushes the ft of the rear downward(pinion angle) at take off .......if both shocks are behind the rear it pushes it upward (pinion angle)..........to keep it from rotating too much stager the shocks...one behind the rear .....one in frount.......help keep the tires planted.......
This is somewhat an erroneous statement. A shock is a static unit that can neither push nor pull. On acceleration, the clockwise rotation of the driveshaft causes the pinion to technically rise. Stagering the shocks on either side of the axle center line is done to help eliminate wheel tramp during hard braking or rapid acceleration, which inturn does help keep the tire in contact with the road surface. .
And that usually only comes in to play in any noticable way on a parallel leaf spring live axle setup anyway.
Right, we're working with ladder bars here if memory serves. Thus eliminating (and the WHOLE perpose for them) any "axle wrap." As for shock angle, 90 degrees, or plumb, is for straight line drag racing. Most ch***is books I've studied recommend no more than 12 degrees, toward center, for both shocks in a street application. Although 20 or 15 degrees will work, I'd tend to agree with the ch***is books. Once the angle of the shock is over a certain amount, I'm sure it does add a bit of side play (or "pushes" the axle) toward the oppisite side of the car in a corner. Although not noticable, I'm sure Detroit doesn't place shocks at more than 12 degrees for a reason. Just a thought.
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