rear end movement - ZR-1 Net Registry Forums

crazyb1 · 05-04-2007

I had my rear right wheel bearing/hub assembly replaced last week. Today I noticed that that the same wheel was squeeking again. I also noticed that when I accelerate and decel, the rear end shifts under load, and then shifts back when unloaded. It's very unnerving when at highway speeds you shift and the back end shifts. That's not right. What gives?

Ccmano · 05-04-2007

What you describe was happening on my car before I changed out the rear hubs. So I would suspect there is a problem with the install that was done. Of course deteriorated rubber bushings can cause the same feeling. I would jack one rear wheel off the ground at a time, grab the top and bottom of the tire and see if there is play in the bearing or in the rear suspension bushings. You may have to have someone else watch the bushings to check for movement. Just be safe when jacking the car and use a jack stand to support the car.

tomtom72 · 05-05-2007

I would respectfully add from an apprentice Z owner that you might also check the "C"-beam bolts? If they come loose at the anchor point at the diff housing you could get some pinion rotation...wind-up under load and un-winding under no load....the beam attaches at the front of the diff housing where the pinion gear is.

Just a thought.

Tom

bldavis11 · 05-28-2007

I'm just curious what the outcome of this was. Bearings gone bad?

tomtom72 · 05-29-2007

Quote:

Originally Posted by bldavis11

I'm just curious what the outcome of this was. Bearings gone bad?

crazyb1 · 05-29-2007

I've been out of town for a few weeks. The tire place couldn't figure it out. I just lost my mechanic I've used for the past 9 years so I'm trying to find a reputable shop for the Z. I did drive it a little this past weekend and I noticed that when stopped and I pressed on the brakes, a squeek/type noise comes from the right rear axle area. Same spot as before. Maybe I missed this but could the brakes have something to do with this?

bldavis11 · 05-29-2007

Quote:

Originally Posted by crazyb1

I've been out of town for a few weeks. The tire place couldn't figure it out. I just lost my mechanic I've used for the past 9 years so I'm trying to find a reputable shop for the Z. I did drive it a little this past weekend and I noticed that when stopped and I pressed on the brakes, a squeek/type noise comes from the right rear axle area. Same spot as before. Maybe I missed this but could the brakes have something to do with this?

The brakes could certainly cause squeeks. You could have a caliper that's not releasing all of the way among a number of other things. Jack the right rear and spin the tire. Does it bind?

crazyb1 · 07-30-2007

Update and advice: Found out the new hub/bearing assembly was bad. It will be replaced. Also, the mechanic found that the rear arm bushings were cracked and worn. He's trying to replace the whole arm assembly w/bushings but he can't find the whole assemblies from Chevy, and other parts searches. Can/should he just replace all of the rear bushings with one of the available poly kits from a favorite vette catelog or should hereplace all bushings and control arms. That sounds a lot more expensive!

bldavis11 · 07-30-2007

Quote:

Originally Posted by crazyb1

Update and advice: Found out the new hub/bearing assembly was bad. It will be replaced. Also, the mechanic found that the rear arm bushings were cracked and worn. He's trying to replace the whole arm assembly w/bushings but he can't find the whole assemblies from Chevy, and other parts searches. Can/should he just replace all of the rear bushings with one of the available poly kits from a favorite vette catelog or should hereplace all bushings and control arms. That sounds a lot more expensive!

Why do you need new control arms? I'm missing something.

Ccmano · 07-30-2007

Sounds like it's time for new bushings, the vette catalogs carry them all, poly or standard. Personnaly I'd go with the poly. There's even a variety that has graphite impregnated poly. (less chance of squeeking)

Your mechanic should be able to replace the bushings only.
Hans

05-04-2007	#1
crazyb1 Join Date: Jul 2005 Location: Star, Idaho Posts: 56	rear end movement I had my rear right wheel bearing/hub assembly replaced last week. Today I noticed that that the same wheel was squeeking again. I also noticed that when I accelerate and decel, the rear end shifts under load, and then shifts back when unloaded. It's very unnerving when at highway speeds you shift and the back end shifts. That's not right. What gives? __________________ '90 ZR-1 Red/Red #1239 SGC P/P Plenum/IH, Headers, B & B, Hurst, K & N "Red RocketShip!"

05-04-2007	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: rear end movement What you describe was happening on my car before I changed out the rear hubs. So I would suspect there is a problem with the install that was done. Of course deteriorated rubber bushings can cause the same feeling. I would jack one rear wheel off the ground at a time, grab the top and bottom of the tire and see if there is play in the bearing or in the rear suspension bushings. You may have to have someone else watch the bushings to check for movement. Just be safe when jacking the car and use a jack stand to support the car. __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

05-05-2007	#3
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: rear end movement I would respectfully add from an apprentice Z owner that you might also check the "C"-beam bolts? If they come loose at the anchor point at the diff housing you could get some pinion rotation...wind-up under load and un-winding under no load....the beam attaches at the front of the diff housing where the pinion gear is. Just a thought. Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

05-28-2007	#4
bldavis11 Join Date: Mar 2006 Location: Portsmouth, VA Posts: 245	Re: rear end movement I'm just curious what the outcome of this was. Bearings gone bad?

05-29-2007	#6
crazyb1 Join Date: Jul 2005 Location: Star, Idaho Posts: 56	Re: rear end movement I've been out of town for a few weeks. The tire place couldn't figure it out. I just lost my mechanic I've used for the past 9 years so I'm trying to find a reputable shop for the Z. I did drive it a little this past weekend and I noticed that when stopped and I pressed on the brakes, a squeek/type noise comes from the right rear axle area. Same spot as before. Maybe I missed this but could the brakes have something to do with this? __________________ '90 ZR-1 Red/Red #1239 SGC P/P Plenum/IH, Headers, B & B, Hurst, K & N "Red RocketShip!"

07-30-2007	#8
crazyb1 Join Date: Jul 2005 Location: Star, Idaho Posts: 56	Re: rear end movement Update and advice: Found out the new hub/bearing assembly was bad. It will be replaced. Also, the mechanic found that the rear arm bushings were cracked and worn. He's trying to replace the whole arm assembly w/bushings but he can't find the whole assemblies from Chevy, and other parts searches. Can/should he just replace all of the rear bushings with one of the available poly kits from a favorite vette catelog or should hereplace all bushings and control arms. That sounds a lot more expensive! __________________ '90 ZR-1 Red/Red #1239 SGC P/P Plenum/IH, Headers, B & B, Hurst, K & N "Red RocketShip!"

07-30-2007	#10
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: rear end movement Sounds like it's time for new bushings, the vette catalogs carry them all, poly or standard. Personnaly I'd go with the poly. There's even a variety that has graphite impregnated poly. (less chance of squeeking) Your mechanic should be able to replace the bushings only. Hans __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.