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Thoughts on cutting backing plates.

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Old 03-12-2007, 12:09 AM
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Default Thoughts on cutting backing plates.

I recently purchased a used 12 bolt. I need to install my backing plates and was wondering if anyone has cut the backing plates so they can be installed without pulling the axles and pressing new bearings on.

Its a 33 spline axles.
Basically I want to know if this is safe.
And do the backing plates need to be machined to fit over the bearing.
I am using stock 94 LT1 brakes.
Old 03-12-2007, 01:10 AM
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LT1 Brakes should fit over the end of the axles. When I upgraded from drum to rear disc on my 94 I only had to remove the drum flange and bolt on the disc flange. You'd still have to pull the axle out to mount the flanges, but you don't need to have the bearings pressed.

Last edited by ROCNDAV; 03-12-2007 at 11:47 AM.
Old 03-12-2007, 01:22 AM
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do it
Old 03-12-2007, 11:38 AM
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The caliper brackets mounts over the axle tube:


Last edited by ROCNDAV; 03-12-2007 at 11:47 AM.
Old 03-12-2007, 12:32 PM
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I cut mine to take them on and off (LS1 brakes) without fooling with the bearings, those brackets are plenty stout. I couldnt use the parking brake anymore naturally but that stuff was long gone anyhow, LT1 stuff is different though. I have strange rears on the car now and they are open on one end as well.

But I remember when I bought my rear new it had some extra spacers to space the axles out a little with LT1 brakes so if the rear was in a LS1 car you may need those to get everything lined up and and press the bearing off anyways..
Old 03-13-2007, 03:00 AM
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Cool. Thanks for the replies.
I guess I am just going to have to get in there and see whats what. I want to get this problem solved before I install the rear. Pulling the axles will be much easier if they indeed have to come out.
Old 03-13-2007, 06:36 AM
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It is not a problem to cut the backing plates. We do it all the time. Any aftermarket plate will be open and they are usually made from 1/4" aluminum... That 1" thick piece of steel on your LT1 will be fine!

Also KP is correct, the LT1 cars do require a .125" spacer behind the bearing to push the rotor out for stock caliper alignment.
Old 03-14-2007, 10:36 PM
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Originally Posted by XtraCajunSS
It is not a problem to cut the backing plates. We do it all the time. Any aftermarket plate will be open and they are usually made from 1/4" aluminum... That 1" thick piece of steel on your LT1 will be fine!

Also KP is correct, the LT1 cars do require a .125" spacer behind the bearing to push the rotor out for stock caliper alignment.
do you by chance have a picture of how you cut them? Or are you just cutting the bottom section out that would make the backing plate look like the lower half of a "H" Could this also be done for a 9" rear end and be considered safe?
Old 03-14-2007, 10:48 PM
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I may be a bit dense here, but why the need to cut them? Is it just to avoid pulling the axles when installing the plates? or is there some other reason for drag racing (swapping out rears?)
Old 03-15-2007, 12:20 AM
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well I just picked up another set of LT1 backing plates today as the other ones I bought for some reason wouldn't line up with my moser 9" housing ends. Therefore I don't know which backing plate is which and won't know unless I could bolt it all up on the housing which would need the backing plates already pressed on. Each backing plate is stamped with a different number on it but I can't find the GM part number for which side is which online anywhere, so having them cut like a "C" shape would let me swap them if needed and not mess up 2 brand new bearings.
Old 03-15-2007, 03:50 AM
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Thats where I am at. Basically new bearings and I don't want to trash em.

So let me get this straight.

I measure the diameter of the axle, cut the backing plate just a wee bit bigger and slide the backing plate over the axle. Backing plate goes against the bearing and I install the 4 bolts to snug the bearings into the axle housing. Is this correct?
Where do the spacers come in? between the backing plate and the bearing?
Am I going to have to cut them too?

Where can I get some of these spacers?

Thanks for taking the time to answer all my annoying questions.....I've only dealt with C clip axles up till now.
Old 03-15-2007, 08:45 AM
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Originally Posted by xpndbl3
do you by chance have a picture of how you cut them? Or are you just cutting the bottom section out that would make the backing plate look like the lower half of a "H" Could this also be done for a 9" rear end and be considered safe?
I cut them between the two holes farthest apart (the top). Just measure the diameter of the axle at the point between the bearing and the hub and cut a slot just a little bigger.

Shane
Old 03-15-2007, 08:48 AM
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Originally Posted by revtime
Thats where I am at. Basically new bearings and I don't want to trash em.

So let me get this straight.

I measure the diameter of the axle, cut the backing plate just a wee bit bigger and slide the backing plate over the axle. Backing plate goes against the bearing and I install the 4 bolts to snug the bearings into the axle housing. Is this correct?
Where do the spacers come in? between the backing plate and the bearing?
Am I going to have to cut them too?

Where can I get some of these spacers?

Thanks for taking the time to answer all my annoying questions.....I've only dealt with C clip axles up till now.
See my above post... As far as spacers are concerned, if your calipers don't line up with the rotors properly, you have a choice of installing spacers under the rotor or cutting the bearing off and installing it between the bearing and axle flange.
Old 03-15-2007, 12:58 PM
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Originally Posted by revtime
Thats where I am at. Basically new bearings and I don't want to trash em.

So let me get this straight.

I measure the diameter of the axle, cut the backing plate just a wee bit bigger and slide the backing plate over the axle. Backing plate goes against the bearing and I install the 4 bolts to snug the bearings into the axle housing. Is this correct?
Where do the spacers come in? between the backing plate and the bearing?
Am I going to have to cut them too?

Where can I get some of these spacers?

Thanks for taking the time to answer all my annoying questions.....I've only dealt with C clip axles up till now.

Ohhhh, so this 12 bolt has the C clip eliminator option?
Old 03-16-2007, 02:46 AM
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Originally Posted by ROCNDAV
Ohhhh, so this 12 bolt has the C clip eliminator option?
I believe so. The axles are tied to the rear with wire, I think to keep them from popping out. I am thinking the backing plate is whats going to be holding the axle in.

I will get some pics this weekend.

Thanks
Old 03-23-2007, 12:20 PM
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I've never dealth with a C clip eliminator before, but to me, that doenst look like it has one.



http://www.moserengineering.com/Page...iminators.html

I believe if you pull the rear cover off (have a pan ready to catch the gear oil), remove the center piece and pull the clips outs (if they are in there) then the axles will just slide out, enabling you to install the backing plates.
Old 03-23-2007, 07:44 PM
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That looks just like my moser 12 bolt.I can't tell for shure in the pic,but it looks like the spacers are on the axles already.It's simply a steel "ring" so to speak.I am sort of in the same boat,I lost one when I pulled the bearings off mine last time.I have a friend that owns a machine shop that's going to make me one.
Old 03-23-2007, 09:51 PM
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Originally Posted by ROCNDAV
I've never dealth with a C clip eliminator before, but to me, that doenst look like it has one.



http://www.moserengineering.com/Page...iminators.html

I believe if you pull the rear cover off (have a pan ready to catch the gear oil), remove the center piece and pull the clips outs (if they are in there) then the axles will just slide out, enabling you to install the backing plates.
The bearings are pressed onto the axles. The backing plate bolts on to hold the bearing in thus keeping the axles in as well. I think thats how it works.
there is a spool in this rear and I don't think there is any way to do C clips with a spool. I am going to pop the axles out this weekend and see if I can get a part number off the bearings and order some new ones.
thanks for the replies.
Old 01-24-2008, 07:33 AM
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does anyone have pictures of them cut at all? id like to see them.
Old 01-25-2008, 08:41 PM
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