79 TRANS AM FRONT END CLUNK

[Jolo]

I have a z code 400 4 speed. I have had the car on the lift with my wife turning the steering with the wheels on the ground and off. The only see a little play in the steering gear, but that does Not explain the clunk I get when slowly rolling in reverse with the steering hard right. Does not happen with wheel straight or hard left. I don’t see play in the tie rods, idler arm, or the center link. The upper and lower control arm bushings seem fine and I cannot generate any play in them when I pry against them.

i guess I will have to bring it in for inspection, but before I incur the cost, do do you any similar experiences out there?

thanks
joe

 

[melsg5]

You don't mention testing the ball joints for play or the condition of the front stabilizer bar end links.
The upper control arms dont appear to have lost any alignment shims?

 

[cammerjeff]

Also do your inner tie rod ends have grease zerks that point up? I have found that if the zerks point up they under some conditions can contact the bottom of the oil pan when the steering is full lock left or right. I have had to shim up the motor mount frame plates to cure it.

Just something else to look at

 

[Jolo]

Hey there

Sorry, I did not mention specifics but I did check everything, even though everything looks brand new. Shims still in tact. Stabilizer links are new and tightened down properly. No play in the ball joints with wheels off the ground and pry bar under tire or by moving tire in and out at 3 and 9 o’clock. The right side wheel bearing was loose, but after I tightened it, I still have the clunk. My left front outer brake pad is moving, so I need to pull the caliper and see if it is frozen, but the car is not pulling and that is not the clunk I am hearing and feeling under the floor.

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[melsg5]

You checked engine mounts and transmission mount?
The exhaust isnt hitting the frame?
The brackets for the front stabilizer bar bushings, not the end links, are the original factory brackets?

 

[Jolo]

When I lifted the engine to install the new oil pump, the front motor mounts looked good and i just rechecked the trans mount bolts at the tranny and the frame because I did replace the clutch. I checked the trans to bell housing and bell housing to engine bolts. The stabilizer bar bushings look good with the original brackets tightened down I really think it feels like the steering linkage because I can feel it under my feet and it only happens with the wheels turned far right and when rolling in reverse from a complete stop. I‘ll check the steering box to frame bolts but I don’t see any movement when the steering wheel is turned right and left, but there is some movement in the gear box shaft at the Pitman Arm. The box is leaking so I will start with a remanufactured unit from Classic Industries and see if that fixes the problem. Then, I think I need to focus on the center/drag link and the tie rods. There is probably some play I am just not seeing.

 

[Jolo]

Thanks much for the input. Problem solved. The clunk was a loose pitman shaft in the steering box. I used my phone to video the front linkage and steering box when turning the wheel. The box was leaking also, so I replaced it with a rebuilt close-ratio unit from NAPA. To ensure I had a completely clean system for the new box, I replaced the pressure and return lines, added an in-line filter on the return line and installed a rebuilt pump and reservoir (NAPA). The tie rods had been replaced and new outers are on back order, so while I installed a new Proforged Center/Drag Link (AMAZON) I reinstalled the existing tie rods, but I replaced the Pitman Arm (used on EBay, hard to find) and Idler Arm (AMAZON). The inner tie rods were available from Holley Performance but the outers are on back order. Good thing I called Holley, because they do not email or advise on back ordered items. I greased all joints. The car handles and drives so nicely now. Often, you do not realize how bad something is until ii is replaced.

Kind regards,
Joe

 

[melsg5]

Thanks for the update

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