[techteacher5561]

Been chasing a clunk noise. Had several diff people look at diff things to try to develop a game plan. Night before last, I took a easy low speed trip down the street two miles to a local car cruise, every time I shifted heard a clunk type noise, seemed to correspond to the front end raising and lowering w/ every shift.

First- coworker is an ASE cert mech, he helped me jack up frontend of car w/ jack under lower A arm, he wiggled the wheel movement seemed excessive to him, told me the ball joints are worn and to replace them.
Quest #1- would it make sense to do tie rods ends at same time as the front end will be apart and easy to do- didn't think to have him test out tie rods- and I'm not sure how to do so on my own.

I jacked up car and grabbed drive shalf at front and rear tried to see if the U JOINTS would deflect up/down or side to side- no apparent movement-
Quest#2 these U JOINTS should be "good" if they don't deflect right?

Also looked closely at the pinion to see if it would deflect when I was moving the shaft up/down and side to side, thought maybe the crush nuts might have loosened up- no movement -
Quest#3- should be OK?

Last night- Had friend stand out side car and listen for clunk- he said he hears it coming from the BACK of the car when I release clutch and apply throttle ( not hammering it just like normal driving to get the car moving.
He laid on ground and watched under car to look for unusual movement. he saw the pinion part of the rear end rotate up ALOT on acceleration pretty much corresponding w/ the clunk noise. if it matters the Single leg rear was replaced by previous owner w/ a 12 bolt posi out of a chevelle 3:23 gears
Question #4- this excessive upward rotation of the rear end would mean what?
-bushings? ( they look "old" and weathered)
-replacement of stamped steel control arms w/ ?
-weak springs need to be replaced?

Really curious if others have had the excessive upward rotation problem and what they did to solve it.

I tried searching the threads under "pinion rise/ pinion lift" and got some info but not really directly related- I have horrible luck guessing the right search words so if someone knows a specific thread that'd be cool to share too.

I have gotten info from other PY'ers that changed their suspension to a UMI upper and lower control arms to fix the wheel hop or torque steer, but I don't know if my problem is the same- they never mentioned clunking noises.
Yes if I hammer on it I'll get wheel hop too, but not sure if that means anything in particular.

Thanks Howard

[fdowdy]

This may sound silly, but I once installed a complete rearend out of a '64 GTO into a kid's tempest. He experienced the clunk syndrome that you're describing. Turned out that I hadn't torqued the bolts for the arms tight enough. He got someone to do that and the clunk went away.

[68addict]

Perhaps the u-joints are shot. Check those...esp since the rear rises, there is a U-joint back there and it may be whipped.

EDIT Do the tie rods too. Once you have front apart..I think you check for them by wiggling wheel left to right???? ....but I am not sure

[techteacher5561]

I editted the post Anthony's suggestion made me realize I left the word U JOINT out of question #2 .

The U joints don't seem bad on testing for deflect by HAND. however I'm seeing SO much upward rotational movement in the rear end that joint is getting WAY more force put on it by the engine then I could do by hand.

I'm leaning towards replacing the control arms back there.
not sure if you must do lower and upper at the same time.
Surfnuke used this kit With good luck
http://cgi.ebay.com/ebaymotors/68-72...mZ130124597452

[naughtygto]

You might check the trans mount to see if its broken. As for the hopping at full throttle, try installing anti hop bars from Lakewood. I did on my A body and now there is no hopping. I also boxed my lower rear arms.