Rear Knuckle Replacement/ Need Help

[RaycinSS]

Anyone have access to the factory repair manual with the torque specs and the procedure for replacing the rear knuckle?

Had a clunk coming from the rear when starting from a stop or decelerating and accelerating. Was fearing that it might be the differential but it appears that the bushings for the left upper control arm are shot. GM wouldn't sell the bushings separately and I bought a complete new knuckle with the bushings installed.

I'm trying to get this new one on before the weekend is over since this is my daily driver. Looks like it may be reasonably straight forward but any help and especially the torque specs for all the bolts would be greatly appreciated.

['10CamaroDude]

All the bolts need to be FINAL torqued at ride height. You can tighten them up, then
the car has to go to ride height for final torque. I just did all mine back there, and
to be honest, I didn't torque them on, I just honked them on.

However, here ya go:


AS you can see, they're torque-to-yield bolts, so you will need to make a decision on how tight you
REALLY want them. You can reuse the bolts up to three times in this application, but they want you
to buy new ones. I have never bought new, and never had them come lose or cause problems. I just
just went to 150 ft-lbs on those large bolts.

The reason you can't convert degrees to a final torque value, is because the bolt size and thread changes the torque.
Thus, a 3/8 bolt turned 120 degrees will be a different torque than a 1/4 bolt turned 120 degrees.

[RaycinSS]

10CamaroDude,

Thank you that is extremely helpful. Do you happen to know if the specs are the same for all models 10-15 or if any are Z/28 specific since the bushings are different?

['10CamaroDude]

None of that is model specific. The bolts to not clamp the bushings in place, they
clamp the sleeve in place. Does not matter what the bushing is, or is made of, the
clamping force has to be the same, on that metal sleeve. You can rip yours out and
put POLY bushings in, the torque specs remain the same. Remember, AT ride height
from snug, to final torque.

[RaycinSS]

Originally Posted by '10CamaroDude

None of that is model specific. The bolts to not clamp the bushings in place, they
clamp the sleeve in place. Does not matter what the bushing is, or is made of, the
clamping force has to be the same, on that metal sleeve. You can rip yours out and
put POLY bushings in, the torque specs remain the same. Remember, AT ride height
from snug, to final torque.

Makes perfect sense. Would you happen to have the brake caliper to knuckle torque spec?

['10CamaroDude]

Originally Posted by RaycinSS

Makes perfect sense. Would you happen to have the brake caliper to knuckle torque spec?

Brake Caliper Bracket Bolt - Rear (L99, LS3) 40 N.m + 90 degrees or 30 lb ft + 90 degrees.
Brake Caliper Guide Pin Bolt - Rear 27 N.m or 20 lb ft
Brake Hose Fitting Bolt 40 N.m or 30 lb ft
Brake Rotor Bolt 10 N.m or 89 lb in
Brake Shield Bolt 9 N.m or 80 lb in

Same specs for V6.

[aris]

It's an easy repair. I had the exact same issue with mine late last year.

['10CamaroDude]

As long as you do not loosen any the bracket side bolts on the UCA, LCA, TOE, or
TRAILING arms, you should not have to worry about having to get it aligned. The
major ones being the TOE and LCA cammed bolts. I replaced all those arms, except
the upper, and even marked the spots, and the rear tires were " / / " toed like that.
I lost one mark when I had to burn out the driver side LCA bolt from the bushing
sleeve. Got it all lined up a few days later.

[SIM GhostrdrZ]

Originally Posted by aris

It's an easy repair. I had the exact same issue with mine late last year.

How many miles on yours when you had the issues? Did you replace the entire knuckle as well?
Thanks

[SIM GhostrdrZ]

Originally Posted by RaycinSS

10CamaroDude,

Thank you that is extremely helpful. Do you happen to know if the specs are the same for all models 10-15 or if any are Z/28 specific since the bushings are different?

This might be a common replacement part. How many miles when it began giving you issues?
Thanks

[aris]

Originally Posted by SIM GhostrdrZ

How many miles on yours when you had the issues? Did you replace the entire knuckle as well?
Thanks

Fairly low - maybe 18,000. A lot of track use though. Other than that, the rest of the car is like new.



I replaced the entire knuckle.

[SIM GhostrdrZ]

Originally Posted by aris

Fairly low - maybe 18,000. A lot of track use though. Other than that, the rest of the car is like new.



I replaced the entire knuckle.

Having 2 with the same issue peaked my interest. I’ll have to see if the rear knuckles can still be had through the GM system. I think the parts outlet had them for $150 or less.
Thanks for the info and didn’t mean to hijack the thread

['10CamaroDude]

The knuckle isn't the problem, it's the bushings. They can be pressed out and
new ones put in. I have a set of polys for the knuckle side of the UCA. The
knuckle is a sold piece of aluminum, which is easier to replace than pressing out and
in, bushings. At 18,000 miles, would be under warranty had the time not expired 1st.

[SIM GhostrdrZ]

I just finished up ordering both rear knuckles. Both are supposedly discontinued and a few right ones in the system but 2 wholesalers from opposite sides of the country pointed to one Cali dealer for a left one. I called and it was spoken for but had been awhile. They called back and said they’d sell it to me. So if you need them, I’d suggest grabbing some if you can find them. Hopefully GM gets another run of them. I don’t need them now but like to have spares of wear items. If I ever replace them, I’ll find a good set of bushing replacements to make those spares. Not sure even extended warranty would help you if there are no parts to be had. These are only Z28 specific, unlike a lot of suspension parts that are shared with Zl1 or 1le.