I have an 88 formula with a 350 tpi and 5spd.
Has a 4th gen rear end, with a 342 posi.
when you let off the clutch, the rear end hops like a ****!!! its bad.
If you look under the car, the rear end pinion moves up and down like crazy!

so I am thinking either,
Bad torque arm or bushing.
Perhaps bad tranny?
Bad clutch?
Slave cyl needs to be bled?

spohn lower trailing arms have been put in to try and reduce it, w ith no joy.

I need some ideas

 

I thought you sold your car?

tranny mount and or torque arm are first thoughts, since you said the pinion moves. oh, pinion as in the whole rear end rotates right? not like the rear end stays, but the pinion moves? (that'd say pinion bearings...)

 

No, I am parting it out! I bought the formula today.

The whole rear end moves, I will replace the shocks tomorrow, and check the torque arm, if it is bent I will buy the edelbrock onesince it is the cheapest. Hopefully it isnt anything major, but it is bad... just letting off the clutch makes that sucker hop like crazy.

 

Broken or busted torque arm?

Worn bushings on frt of torque arm of failing tranny mount?

Also worn old stock control arm bushings in the rear contribute greatly to this.

later
Jeremy

 

I have spohn rca's on the back so I know that isn't it. if the torque arm is busted, I will just buy the edelbrock one I guess.

 

Well, I changed out the tranny mount with a poly one, unfortunately it did not fix the problem. As I was taking it for the test drive, (you let it slowly out of gear, the car shudders violently, rear hops around.) then I heard a loud bang! I think the clutch exploded. I can no longer start the car, (since it is manual) and all clutch resistance in the pedal is gone. I checked to make sure the slave didnt blow out. So tonight, I will take out the tranny and clutch and see where we are at. However, this thread is now off topic and is a transmission section topic. Thanks for your help guys.