Hi
I just put my '85 Z28 in for its annual roadworthiness test (what we in the UK here call the 'MOT' or Ministry of Transport test) and the mechanic failed it on rear-axle bearing rock, but to me it looks like endfloat at the wheels - I can't get the wheels to rock at all but they move in & out about a sixteenth of an inch or a little less.
The mechanic is adamant it's unacceptable.....
The question is, should I expect to see endfloat, and if so, what is an acceptable amount?
Thanx
Malc

 

in and out movement is normal. print this out and show him, like it'll do some good.

 

1/16" (2mm) is about right. They all have about that much, sometimes more.

Sounds like your "roadworthiness inspector" needs to get checked out by the "car knowledge inspector".

 

yup, natch. But how much?

 

Thanx RB83L69 - my last post went before I saw yours.
I'll pass this back. Can't see any mention in the Chilton or Haynes books so is there anywhere I can get this a bit more official if he screams and hollers? ;-)

Malc

 

if it rocks when you pull the wheel in and out, just replace the C clips... that usually snugs it up some.

 

1\16th of an inch endplay is perfectly acceptable on C\clip cars. Being in the UK, the inspector is probably not familiar to GM cars using C\clips. Most European cars do not use this method.

Hard to find specs on endplay...but take it to another inspection station with an inspector who is knowledgeable about GM c\clip rear ends.

C\clip replacement will may not help, although it;s certainly worth a try. On my car ( 10 bolt and Eaton Posi ), with new C\clips, the endplay was .050". Not a problem with PBR rear brakes ( sliding calipers ), but when I switched to 4-Piston WilWoods this caused pad knock back and an inconsistant low pedal.

Solution was to machine some " Lash Caps " that fit over the end of the axles ( between the axle end and the pinion cross shaft ).

Again...not necessary with stock rear brakes.

 

You might find this link interesting. Dirt cheap way to eliminate virtually ALL axle end-play....

Thicker C-Clips