Rear Disc Help

[89BlazerK5]

i'm trying to do a rear brake job. it's got a disc conversion on the 10 bolt. i had no idea what the brakes came off of. after spending an hour in O'Rilley's, we figured out the calipers are from a 1984-1986 Ford Mustang SVO. but, the rotors are 6-lug.... and we have no idea what they could be from. anybody know what had 6-lug rear disc??? all i can think of is '99 and up chevies (drum e-brake inside rotor), Nissan, Toyota, and newer Fords.... the people at O'Rilley's looked at all the rotors they had in stock, and couldn't match anything. any ideas? /forums/images/graemlins/confused.gif

 

[Beast388]

Did you try matching it to a 6-lug Chevy front rotor? /forums/images/graemlins/thinking.gif

 

[89BlazerK5]

it's definately a rear rotor... it's much smaller than a front.

 

[Beast388]

[ QUOTE ]
it's definately a rear rotor... it's much smaller than a front.

[/ QUOTE ]

Did you try a 99-up Chevy 1/2 ton rear rotor? /forums/images/graemlins/thinking.gif

 

[89BlazerK5]

i'm pretty sure the newer chevies have the drum stye E-brake inside the rotor.... mine do not.

 

[Rob 85K5]

Toyota and Nissan are 6 lug??

 

[89BlazerK5]

they checked all the nissan and toyota rotors, and they were all substantally smaller. it doesn't matter much anymore. i was wanting to know the specs of the rotor to know if it had enough surface left, or to know what to buy to replace them........ BUT, i got them resurfaced, and there was just enough surface left. .......... so, i'm good to go.

 

[CyberSniper]

Take some pictures of it.

It might be a Trooper rotor.

Like I said, take some pictures of it. I've spent tons of time researching the easiest way to do rear disc and checked out just about all the rotors with 6 on 5.5 or close pattern.

 

[89BlazerK5]

 

[CyberSniper]

OK, what is the thickness of the part the pads rub on?
What is the diameter of the rotor?

What is the thickness of the hat (the part sandwiched between axle and tire)?
What is the diameter of the hole in the hat?

 

[Confedneck]

those sure do look like a gm rotor to me..

 

[89BlazerK5]

what is the thickness of the part the pads rub on?..... .975" (just resurfaced)
What is the diameter of the rotor?...... 11.5"

What is the thickness of the hat?..... .15"
What is the diameter of the hole in the hat?....... 3.575"

the inside of the hat is offset from the inside pad surface 2.075"

 

[CyberSniper]

Yeah, they look like the thin two piece IFS rotors. The first thing that made me think that is the stamped steel center with the 14mm lugnut holes. However, it has a 3 1/8" center hole which won't fit since our axles require a 3.5" center hole.

I can't remember the dimensions of the IFS rotors but those numbers look pretty familiar. They're just a tad different than our front rotors as far as the offset, diameter, and thickness go.

They are probably modified thin two piece IFS rotors. Two piece meaning there is a stamped steel hat set in a cast iron rotor. These rotors seem to becoming rare. The last time I bought them AutoZone was the only place that had them.

Anyway, call up the local auto parts stores and ask them for this rotor:
1989 K1500 standard cab long box. This is the thin rotor. The extended cabs got a thicker rotor. Then ask them if the rotor is a stamped steel center section rotor.

You can then enlarge the center hole. I used a 3.5" hole saw in a drill press. You can probably get away with doing it with a die grinder if you're careful.


Here is a picture of what I did for rear disc brakes:

The white things around the studs is 1/2" CPVC that I used to center the rotor just in case I was off in my hole saw manipulation.

 

[89BlazerK5]

thanks.....

mine have those metal ring things on the studs to keep the rotor centered. the holes in the rotor are bigger than the studs.

i wonder why the guy who did the conversion used Mustang calipers rather than chevy ones....

i don't need new rotors..... mine will work. i was just wanting to know for future reference.

thanks for the help!

 

[dyeager535]

Have them pull the front rotors for a '95-ish Toyota Tacoma 4wd. Checked a set without my good tools, looked like the diameter was about right, the thickness was under 1", and the cutout in the hat looked large enough to clear the axleshaft flange.