I have a 98 Z28 and I have a pretty good shop installing my 3.73 gears and they ran into a problem late last night, so they had to keep my car over night so i'm trying to get all the info I can. The gear will not fit it is too tight. Not enough backspacing in there. Is there anything that we should look at or any problems that usually occur when installing 3.73's.

 

Do you have 3 series carrier ? If so, what could cause that is you have thick 3.73 ring which is for 2 series carrier.

 

what gears did you have? if they were too tight sounds like you bought thick cut gears (for a 2-series carrier) and tried putting them on a 3-series carrier

If it was the other way around (common mistake) then they would be way too loose

 

also...they do have the pinion fully installed with the crush sleeve crushed to achieve proper preload?

 

Yeah I have a 3 series carrier.

 

If they are the right gears, maybe they just don't know how to change the side shims to adjust for more backlash?!

FYI: Decrease the left shim thickness and add the same amount to the right shim. Usually the thickness will be like this:
Left shim: .243" Right shim: .237"

Now if its too tight you would want to loosen it by taking away the total thickness on the left shim, sometimes I just swap them left to right and vice versa and thats enough.

Set backlash in the .007-.010" range favoring the low side of that range - depending on gear pattern. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />