rear clunking under load

[aznpoopy]

well. i installed subframe spacers about 2 months ago. one of the bolts stripped the threads in the chassis, but was fully screwed in. rear made a clunking noise when i drove it around so i parked it. i figured the subframe was floating b/c that bolt was a little loose.

then i had finals, intern, etc. finally i got a chance to get to it today. we drilled out the bolt. we bored out the hole. tapped it, inserted a helicoil. screwed in a new bolt, torqued everything down. lo and behold, the clunking is still there!

the clunking only occurs when you are accelerating at low rpms. it gets quiet and dissappears at higher rpms. the clunking gets faster with road speed. it does not clunk when changing between accel / accel off / braking etc. it sounds like it is coming from the rear driver side (where the threads in the chassis had stripped). there is no clunking during coasting, braking, or engine braking.

i'm at a loss. i figure maybe one of the spacers didn't seat properly? i'm going to take them out tomorrow and see if the clunking goes away. anyone have any ideas? T_T

btw: they are the two piece spl spacers with the top slotted insert.

[NIK90s13]

I was wondering what ever happend to your sub problem. If I understand you right it's a continues clunk? clunk, clunk, clunk? If so wile you are rechecking the spacers, check the drivr line, ie carrier bering, the bolts that hold the diff, your hubs are all the way in your diff, ect.
If I'm thinking right, if it was the sub it shouldn't clunk faster with speed. It should clunk at acelerating, decel, breaking, and hard turning.

[aznpoopy]

yep... only when you accelerate at low rpms. clunk clunk clunk, faster and faster until it dissappears.

i heard the spacers add more noise to driving... but not this kind of noise.

thanks for the suggestions. i'll post up if i find anything.

[vutony]

i have the same problem after dropping my subframe (installed vlsd, subframe spacer, and coils) havent had time to figure it out yet....keep me updated if u find a solution

[projectRDM]

Check for freeplay in the wheel bearing, along with maybe a loose axle nut.

[NIK90s13]

I've got sub spacers on mine, it doesn't clunk at all. I'm still betting drive line because it speeds up.

[aznpoopy]

well i grabbed the hell out of the wheel and tried to shake it every which way but it didn't budge. it was pretty solid.

we retorqued all the suspension arms, which are still all stock in the back. everything checked out.

i started screwing around with the axles, and there's no clockwise or counterclockwise play. we were short on time today, so i haven't checked the six bolts/nuts off the diff.

i didn't try torqueing down that big ass nut on the hub. the cotterpin is still on there, but imma give it a try. i don't have the socket so i'll have to buy one. anyone know what size it is?

I'm still betting drive line because it speeds up.

yeah... it definitely has to be something rotating. diff, axles, hub, driveshaft, etc. i'm going to go back under later this week and look for signs of damage from metal to metal contact. something has to be binding or hitting to make that noise. for now the car is indefinitely parked yet again.

maybe the change in the subframe positioning is causing some contact when the rear squats? that's my best guess at this point.

[projectRDM]

36mm, you knew that.

[Jon-S14]

I'm having the same problem as you right now but my situation is a bit different. I recently installed new camber arms in the rear and after i installed it i noticed the clunk noise on the left rear. So I checked it out and found that the camber arm swivels on a ball joint and was slanted. I re-aligned everthing and went for a drive. Noise went away. A few days later, I took the car for a 4 wheel alignment. After getting it back I noticed that the noise is on the Right rear. I re-aligned that side and checked the left side too and made sure everything was tight and straight. This time, the noise is staying. As for my condition, the clunking comes at low rpm and at low speeds. It gets worse when turning and gassing at the same time. It's really buggin the shit out of me so I hope someone on here will figure this out.

[RedtopTech]

did you torque the arm bolts while suspension was loaded. IF not the bushings twist as the arms move up when you set the car back on the ground which can rip the bushings. Why did you use a heli-coil? If you tapped the hole you should just use a larger bolt. The subframe is under tremendous load and that coil will likely shift up and down.

[aznpoopy]

it went away for me after i swapped axles and installed new diff bushings.

i'm guessing that its the differential bushings.

[Jon-S14]

Can anyone help me out on my situation? It sounds like CV joints clicking inside when I'm turning and accelerating at the same time. Could it be the angle in which the driveshaft is sitting thats causing the noise? My car is lowered with Megan Racing street series.

[Jcommerford92]

i have the same problem. I recently welded the Differential on my s14 and sure enough after i did this i have this clunking noise like described above (under acceleration or cornering). I have some pretty good experience rebuilding differentials and i know my work inside the differential is solid, so that leaves me with the cv/axles. I replaced both cv axles with new oem replacements and the noise went away for maybe the first day of driving and then it came right back. its getting progressively worse and i know the welded DIff isnt helping,but the only thing i can think of is that the oem cv joints were not designed to work at angles now experienced with lowered cars like mine. i didnt have this noise before i welded the Diff because the axles werent locked together therefore they had much less stress when cornering and under straight acceleration. an open differential would allow the cv axles a lot more freedom so they wouldnt bind or wear out rapidly. With the differential now locked any play in the cv joints is now clunking and wearing the cv's because there is no way for the cv axles to release the torsion energy into the open differential. so simply put in the end i think a different quality cv axle with greater angle limitations will fix this. i know the driveshaft shop has what seems like the perfect example of a solution but whos has a grand to drop on axles alone. another alternative might be a q45 differential swap with 300zxtt drivers side and q45 passenger cv axles. as for me i may make up a custom u joint style axle similar to a drive shaft with a slip yolk. hopefully this helps..

[Jcommerford92]

Can anyone help me out on my situation? It sounds like CV joints clicking inside when I'm turning and accelerating at the same time. Could it be the angle in which the driveshaft is sitting thats causing the noise? My car is lowered with Megan Racing street series.


Jon-s14
if i read this right, theres no way its the "drive shaft" is making this noise. when you lower the car the drive shaft stays in the same place it was before you lowered it. However when you lowered your car you did increase the angle on the cv axles. and i think you are dead on in saying that noise is from you cv joints. i would consider a fresh set of cv axles that allows more angle. hope that helps.

[Jcommerford92]

Hey guys. I've been through the same problem and solved it completely. It is the cv joints in the axles. Again, cv joints!!! Haha Basically oem axles use a tripod style bearing that cannot take big changes in angle or length. So as I keep reading above, pretty much everyone including me who has or has had this problem has changed the suspension geometry in some way from its stock form. That also changes the angles in the cv joints and for this set up in our 240's it's basically the end of the tripod bearings hitting the end of their allotted space. Aka the klunking you keep hearing. If you want to keep your ride height basically you have to swap to a ball and cage type cv joint. There are three set ups out there that I know of that will work. Drive shaft shop 600 hp axles if you got the $, 350z axle swap with adapter plates for cars that aren't too low or get nuts lab custom differential output shafts made for 350z axles. I hate to be mean and not give links but searching for yourself is the best way to Get car knowledge and come across new parts. It's really not too hard to find. Hopefully this helps!