C3 A-Arm Cross Shaft Install - Lube?

[Michael C.]

I've removed the A-Arms and bushings from the left side of the car. I've read many posts with tips for installing new bushings. One thing I haven't seen is whether or not the ends on the cross shafts should be lubricated in any way during the install process. Of course I'm referring to the ends that will be inserted into the inner sleeves of the new bushings. At this point before installation the bushings turn freely on the ends of the shafts.

Thanks,
Mike

[Duke W.]

Re: C3 A-Arm Cross Shaft Install - Lube?

It's not clear to me what you are saying. All angular movement in the bushings is deflection of the rubber - like twisting an eraser. The outer shell is pressed into the A-frame and the inner steel bushing is held firm by the bolts. The is nothing to lubricate.

Duke

[Michael C.]

Re: C3 A-Arm Cross Shaft Install - Lube?

Duke, thanks for the reply and sorry for the unclear question. I was thinking there should be some movement of the shaft within the inner sleeve after installation. I came to this conclusion after reading a how-to document on the Corvette Magazine web "Control Arm Bushings...). In step 13 there is this statement: "Make sure that the cross shaft can be turned by hand. It should not bind after it is installed." Is this incorrect, or am I misinterpreting it? After closer inspection of the shafts, I do see what appear to be "teeth" marks on the shoulder of the shaft left by the inner sleeve. To me this would imply that the sleeve is held firmly against the shoulder after the arm is installed and the bold torqued down. This might be consistent with your description of the deflection of the rubber.

Mike

[Duke W.]

Re: C3 A-Arm Cross Shaft Install - Lube?

Forget what you read in any magazine. All you need is the appropriate Chevrolet service manuals. As I said there is no relative motion between steel surfaces. All control arm motion is deflection of the rubber part of the bushing.

Duke

[Terry M.]

Re: C3 A-Arm Cross Shaft Install - Lube?

Duke, thanks for the reply and sorry for the unclear question. I was thinking there should be some movement of the shaft within the inner sleeve after installation. I came to this conclusion after reading a how-to document on the Corvette Magazine web "Control Arm Bushings...). In step 13 there is this statement: "Make sure that the cross shaft can be turned by hand. It should not bind after it is installed." Is this incorrect, or am I misinterpreting it? After closer inspection of the shafts, I do see what appear to be "teeth" marks on the shoulder of the shaft left by the inner sleeve. To me this would imply that the sleeve is held firmly against the shoulder after the arm is installed and the bold torqued down. This might be consistent with your description of the deflection of the rubber.

Mike

Michael
Those "tooth" marks hold the inner sleeve to the shaft once the end bolt is tightened to torque specifications, and the pressure compressing the outer sleeve holds it to the control arm. Any rotation is in the rubber compressed and bonded to those two metal parts. The rubber is intended to take up all the movement (if any). This is why one doesn't tighten the bolt through the end of the shaft until the vehicle is resting at normal ride height. One doesn't want to "pre-load" the bushing. Damage to the rubber is likely to result if the bushing is "pre-loaded." This is also why it is not a good idea to store a vehicle for a long time on a lift using chassis lifting points. Long term storage with the wheels hanging free in the air will keep the rubber in those bushings at the limits of their flex and risks permanent damage to the bushing.

I believe the article you cited is inaccurate if the text reads as you describe.

[Michael C.]

Re: C3 A-Arm Cross Shaft Install - Lube?

Thanks for the clarification Duke and Terry.

[Richard M.]

Re: C3 A-Arm Cross Shaft Install - Lube?

I always brush on a light coating of anti-seize on the shaft ends for the next guy so when they're removed in 25 years for rebuild they come apart easier. They're usually seized to the steel bushing sleeves on original arms.

Also add a bit of blue Loctite to the end bolts. Check your bolts after a while. They can have a tendency to loosen up. You can get a torque wrench on those lowers, but impossible on the upper forward bolts, especially left side.

Rich