Creaking and Groaning in passenger rear quarter

[Zealous]

Ok so I am stumped on this one I have a bad creaking and groaning at low speeds when the right (passenger) rear suspension is unloaded and loaded. So far we have checked over all the bushing and they were replaced within the past 2 years from the paper work. They also all look new and the bolts are all marked was done professionally at Z Car Garage in San Jose by previous owner. We have replaced the rear wheel bearing and stub axle+lugs, repacked and torqued lock nut (280zx without peening) to 200ft/lbs. It was a PITA to get the old lock nut loose. We also did the u-joint in the half shaft. The only thing I can think of is something in the shock/spring. I was thinking of buying some new shocks all round for track days but don't want to spend the money if I don't have too.

I have also read all the good and bad posts about riding on bump stops the lowering of the cars and not much travel and the problems with springs. I don't want to spend the money on coil overs at this point. But back to the problem any ideas what this noise could be? This noise sounds real bad not like the creaking of interior plastic or old car but more metallic and louder almost a worrisome groan which is why I have not driven the car the past few months. There is now noise at highway speed or driving straight just at low speeds and unloading/loading the suspension? Strut housing and A arm all look fine.

So here is the breakdown:

• 1972 Datsun 240z
  
• Panasport 16 inch wheels
  
• New Diff mounts (done with previous owner at ZCarGarage)
  
• New bushing (done with previous owner at ZCarGarage)
  
• New diff rear seal and fluid
  
• New lugs and Torqued lug nuts
  
• Replaced stub axle
  
• New Rear Wheel Bearings (inner + outer + seal + lock nut) and all torqued up
  
• New u-joints on half shaft
  
• New cusco strut brace bars (noise was there before them)
  

Any advice and help would be greatly appreciated especially from people with more experience in this area than me.

[FastWoman]

Creaking and Groaning in passenger rear quarter...

I have a bad creaking and groaning at low speeds when the right (passenger) rear suspension is unloaded and loaded....

It was a PITA

Me too. Old age is a b**ch!

Edited December 27, 2010 by FastWoman

[bobc]

Your post is a little confusing. When you say loading and unloading the suspension, do you mean going over bumps or accelerating and decelerating?

Groans and squeaks are usually suspension parts rubbing against each other and are not necessarily sensitive to speed. More sensitive to movement.

Grinding noises that change (get louder, higher pitched, go away and come back) are more associated with bearings, i.e., universal joints, wheel bearings, etc.

If you just push down and let go on the right rear of the car does it make the same sound?

You might check in the top of the right shock tower to make sure the nut that secures the top of the shock is on tight. I had this problem once and it took me a while to locate it.

You might also WD-40 around where the spring rests in the strut and at the top as well and see if this makes any difference.

Sounds like you've done everything else I would normally recommend checking.

Good luck.

Best,

Bob

[Zealous]

thanks Bobc,

Ill try those. To answer your question it is more over bumps or turning corners. The same sound cannot be produced by pushing down on the car. Not produced by just accelerating/decelerating in a straight line. It is produced by suspension movement as best as I can tell.

Not so much a grinding noise more a groan, I agree that would indicate rubbing/binding. It is not the universal joints or bearings they have all been replaced.

Ill try your suggestions, thanks

[spitz17]

Hey JC, sorry to hear about the problems on your car!

I am guessing you want to avoid taking it to a shop and try to fix it yourself. If you do, however, decide to take it to a shop and don't wanna pay big ZCG bucks, I'd try out Dando's Automotive in Fremont. I have been going their for the Fairlady's head and exhaust work, and they use to be a Z Specialty shop. Ask for Benjyee, I believe he used to work for Rebello and knows his stuff.

[palosfv3]

Is the lock pin in place on the lower outer control arm bolt that passes through the lower knuckle ?

[Oiluj]

James,

I had the exact same problem after I R&R'd the springs and struts.

I tightened everything, no joy. I R&R'd the right rear suspension, (twice), no joy. I did the spray lubrication trick, no joy. Went back and added shrink-wrap over the springs where the contact the mounts and that seemed to solve the problem.

Thing is, I don't really know if that was the root cause of the problem or if I just did something "a little different" upon re-assembly...

Good luck and let me know if there's anything I can do to help.

Julio

[Zealous]

Thanks palosfv3 yes the lock pin is in place.

Thanks Julio, maybe I can bring it around one day and you can show me what you did with the shrink wrap. As an engineer like you I would like to find the root cause of the problem as it is not a pleasant sound and must be doing something to metal somewhere.

Hoping some of the suspension gurus here might know

[Zed Head]

My rear sway bar mounting rubber groaned after I put new urethane end link pieces on. The mounts are right on the body so transmit the noise directly in to the cabin.

Worth checking if you have a sway bar.

[Zealous]

Thanks Zed Head, No rear sway bar but I have been considering one

So was out cleaning up the garage still after the move and trying to sort through things. I tried again pushing down on the car and I get a distinct metal sound almost a clicking but really a clicking which makes me think it is the spring in the perch. Guess I need to jack it up tomorrow and use a spring compressor to see if it is the spring moving in the perch. Any other thoughts?

bobc, while out there I checked the strut nut at the top and it is all tight.

[Oiluj]

James,

I just slid electral shrink-tube on the spring for about 1 coil to cushion the metal-to-metal contact between the spring & upper perch. No that I think back, I also applied a thin coating of silicone grease to the top of the rubber strut cap before installing the strut into the tower.

[Zealous]

Thanks Julio, hopefully that fix works but there must be some underlying problem it is hiding.