im having a problem with the rear suspension. when i changed the tranny out last weekend i noticed that the drive shaft is contacting the tranny tunnel when i launch. i thought it was only the tailpipe making contact. i hve a set of traction bars that i havent installed yet. i also have a new set of gas shocks on the car. ive been trying to hunt some air adjustable shocks but cant find any. suggestions? thanks steve.
Is the car lowered?
Do you have the (a) pinion snubber installed?
Bill
not lowered and no pinion snubber>
I reccamend installing a stock snubber if it is missing. On the later cars they mount like the bottom-out bumpers so if you can't find a snubber, you can modify the bottom out one to work.
Bill
I would stay away from air shocks. They tend to beat out the upper shock mount on cars...
It sounds like your springs are letting the axle wrap up too much.. Adding a snubber(like others said)will help.. Slapper bars would do the same as a snubber or add or get new leaf springs..
When racing my duster I used an extra main leaf with the eyes cut off and removed the smallest leaf to get the rear back down..
i have a 7.5 out of a tbird in it for now. dont think a snubber was on there when i got the rear. ill look at the 2 spare 8.8s i have and see whats what. and i guess its time to add the ladder bars.
Quote from: 4CAMMER72 on January 02, 2008, 10:05:21 AM
...dont think a snubber was on there when i got the rear...
The stock Pinto snubber should be on the car, not the rear.
Bill
What T-Bird did the rear come out of? If it was not made for a leaf spring car, then it has no spring purches (unless you added them). Are the axles tubes (round part) just clamped to the leaf springs? If this is the case then that is likely the cause. I don't mean to sound insulting, but had to ask.
Did the transmission change alter the location (vertically) of the trans. output shaft? There is an angle that is appropriately called the pinion angle on the rear end as it relates to the drive shaft. If that is not set properly (typically with wedges on leaf spring cars, adjustable heim joints on coil spring cars) that can cause the driveshaft to be inclined too close to the tunnel.
Tom
its a turbo coupe rear. i cut the perches off the pinto rear and welded them to the 7.5 rear. used the same pinion angle as the pinto rear so it should be right. it compresses the rear suspension a ton. im actually considering mounting an air bag to help this. how much will traction bars help with this? i have the set that replaces the bottom mountin plate on the axle and bolts to the front of the leaf with a u bolt of sorts.
This could get long.
The stock pinion angle is set for normal driving, and might not be the best for hard launches. The stock rubber bushings in the spring eyes, shackles, and the perch mounts will also have an effect on the torque load. If they are in poor condition or installed incorrectly (I have seen some SCAREY modifications to the perch clamps and rubber) it will cause problems regardless of traction bars. Rear anti-sway bars could also cause problems.
Leaf springs wrap when under load, both in braking and acceleration. This is a good thing as it absorbs shock loads and helps keep traction. "Traction Bars" can hinder this, depending on the set-up, and can decrease traction on take-off. IMHO: If 'wheel hop' is not your problem I would do other things before traction bars.
I would: 1) Make sure the stock pinion snubber is there. 2) Inspect all the rubber including the bottom out bumpers. 3) Be SURE the axle is centered and the pinion angle is CORRECT. 4) Make sure the driveshaft length is correct. 5) Install perch shims to see if that helps.
Bill
thanks, i'll check and recheck everything. ill post up what i find or dont find. unless of course its a bonehead mistake :look: that i cant live down.