Front rotor question

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Doubletop

Junior Member
Joined
May 25, 2020
Posts
21
Reaction score
6
Location
Muncie, IN
First Name
Doug
Truck Year
1987
Truck Model
Sierra 1500
Engine Size
305
1987 GMC R1500 long bed with 305. I have the JB5 code in the glove box for the bigger brakes but when the front rotors came in, the inner bearings are bigger than what came off the truck. Outer bearing and seal are same size. It appears the smaller rotors for the 2” rear shoes are the size currently on the truck. Is it possible someone just put the smaller rotors on the truck at some point or would the whole spindle need changed for that? Can I change it to the larger rotor ?
 

Keith Seymore

Full Access Member
Joined
Jul 13, 2015
Posts
2,639
Reaction score
8,124
Location
Motor City
First Name
Keith Seymore
Truck Year
1987
Truck Model
R10
Engine Size
4.3L
I suppose the first thing to check is to make sure it's the right SPID label in the glove box (make sure the VIN and other option content matches the truck).

If it's a JB5 then it definitely originally had the 1.25" rotors and 2.75" rear brakes. If it doesn't have those now then somebody has made some changes.

K
You must be registered for see images attach
 
Top