19 replies to this topic

[sibhs]

Hi Guys,
can anyone tell me the thickness of a new standard rotor off an LJ/LC?

I have looked up my Manual and it says it's 9.525mm exactly the same thickness as the pad, I think this is a mistake.
Also If you know minimum thickness as well.

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Marty

Edited by sibhs, 01 October 2012 - 09:37 PM.

[dattoman]

12.7mm standard
12mm are throw away thickness

[S pack]

The GMH LC Torana workshop manual has the disc thickness listed as .375" so it appears the specs in your manual are correct.
The pad thickness specs are also the same.

I don't have any data on the minimum disc thickness spec however it I expect it would be approx 1mm less than the original thickness.

Edit: Thanks Datto, I thought they were thicker than 10mm, so the GMH shop manual also has the wrong spec listed.

Edited by S pack, 01 October 2012 - 11:01 PM.

[sibhs]

Thanks guys,
Datto, is 12.7mm the new size? I've just bought a second hand set and they are almost 15mm.

Marty

[S pack]

Mos likely xu-1 rotors.

Yep, XU1 rotors are approx 3mm thicker than standard ones.

12.7mm will be the thickness of new std 6cyl rotors (discs).

[sibhs]

I've just noticed they're one piece, the hub and rotor are one. Is that an XU-1 thing or after market.

[dattoman]

They aren't LC-J ones then
They are LH-X-UC ones

[Ice]

Thanks guys,
Datto, is 12.7mm the new size? I've just bought a second hand set and they are almost 15mm.

Marty

You can buy them new to suit lj torana and there not expensive let me know if you need to get some new
cheers gene

[sibhs]

Hi Gene,
So can I buy new hubs and rotors?

Makes me wonder if the stub axles which came with them are LH or LJ, any way to tell? I can't quite read the numbers on the outside but has an E on the inside.

Marty

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[dattoman]

I think we established the stubs interchange
But the brakes don't
So if your using twin piston cast iron calipers you need the hubs and discs to suit
You can't use the 1 piece version as they foul on the caliper

I prefer the 2 pots (LC-J) over the later caliper myself

LH-X-UC look like this


LC-J ones look like this and bolt to hub

[S pack]

Datto is correct, the LC/LJ stub axles carried over to LH but the discs and calipers are different. You can't use LH discs with LJ calipers.
BTW, you can buy new repro LJ discs but you'll have to find second hand hubs to bolt them to.

[sibhs]

Appreciate your input guys.
I'm finding out that just because you got parts off an LJ, doesn't mean they belong there. Welcome to the world of rebuilding a car.....

This is what I've learn't so far.....
My stub axles are good because LC to LH model are the same except LH ones are used on opposite wheels.
I need LC/LJ hubs to go with LC/LJ calipers. One piece hub/rotor is from the LH series and will foul on the LJ caliper. I can buy new rotors but need LC/LJ hubs.
Am I on the right track now?

Are my calipers the 2 pot LJ ones?
Yes, they're filthy but I'm not getting them reconditioned until I know they're right.

Cheers
Marty

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Edited by sibhs, 03 October 2012 - 06:52 PM.

[S pack]

Appreciate your input guys.
I'm finding out that just because you got parts off an LJ, doesn't mean they belong there. Welcome to the world of rebuilding a car.....

This is what I've learn't so far.....
My stub axles are good because LC to LH model are the same except LH ones are used on opposite wheels.
I need LC/LJ hubs to go with LC/LJ calipers. One piece hub/rotor is from the LH series and will foul on the LJ caliper. I can buy new rotors but need LC/LJ hubs.
Am I on the right track now?

Are my calipers the 2 pot LJ ones?
Yes, they're filthy but I'm not getting them reconditioned until I know they're right.

Cheers
Marty

Yep you're getting the hang of it.
The LC/LJ calipers have two pistons. One behind each pad.
AFAIK the calipers you have are actually HK,T,G but don't panic cause they are the same as LC/LJ except for the cylindrical protrusion cast onto the back of the inboard half of the caliper, LC/LJ calipers don't have this cylindrical protrusion.

Cheers
Dave.

[sibhs]

Yep you're getting the hang of it.
The LC/LJ calipers have two pistons. One behind each pad.
AFAIK the calipers you have are actually HK,T,G but don't panic cause they are the same as LC/LJ except for the cylindrical protrusion cast onto the back of the inboard half of the caliper, LC/LJ calipers don't have this cylindrical protrusion.

Cheers
Dave.

Thanks Dave
Far - out.. more bitsa other cars in the build. What would happen If I cut that protrusion off?

[S pack]

Thanks Dave
Far - out.. more bitsa other cars in the build. What would happen If I cut that protrusion off?

Nothing, as far as I know it's a solid casting, however I would pull the pistons out first and confirm that there isn't a hole running down into the protrusion.

[Ice]

Marty give me a call and i can help you out with the reconditoning of the calipers and tell you where you can buy brand new rotors from pretty cheap

[dattoman]

Or me

[its Paul]

They look the same as what is on the HB, with out Stealing the thread, can LC LJ stubs fit the HB to run 5 stud rims, just a question, as I'm curious

[sibhs]

Marty give me a call and i can help you out with the reconditoning of the calipers and tell you where you can buy brand new rotors from pretty cheap

Or me

Thanks, I'll call you both.
I quickly panic'd and looked on ebay at all the calipers for LJ's for sale and they all had the protrusion on them, are these people just trying to get a better price for a HK/T/G part?