Rear end swap Drum to Disc--- Pain in the Ass???

Hey guys, I basically wanted to know if anyone out there has done a rear end swap from drum to disc brake setup.? Is it much work. What will I need other than the donor cars brake booster and master cyl?

Also, is it poss to upgrade the front brakes from stock size (?) to the larger 1LE size rotors? Will it work without alot of extra fabrication> Thanks all

Will

You can keep your original master cyl and booster, you just have to change the proportioning valve to get the right amout of pressure to the rear discs. As far as the hardware at the wheels is concerned, I hear it's easier to swap the whole rear than to make the drum flanges work with disc brackets and calipers. The 1LE upgrade is a bolt-in replacement for the original front rotors, calipers, and brackets (I think).

Originally posted by TheGreatJ
You can keep your original master cyl and booster, you just have to change the proportioning valve to get the right amout of pressure to the rear discs. As far as the hardware at the wheels is concerned, I hear it's easier to swap the whole rear than to make the drum flanges work with disc brackets and calipers. The 1LE upgrade is a bolt-in replacement for the original front rotors, calipers, and brackets (I think).

it is alot easier toi just swap the whole rearend.

and as for the 1LE stuff, that swap will cost alot of money and does require some fab. to the stock spindles. one of the mag.s is doing complete 1LE swap right now but they didnt get to the point of showing the fab. yet to the spindle. but they did mention it. I believe stainless steel brakes company sells kits as well as Scoggin Dickey chevrolet. but for the money if its cheaper Id just get an aftermarket kit/upgrade.

chris

Thanks guys. I had planned on just swapping thw whole rear end anyway. Know where I could come up with a proportioning valve to get the right pressure?

As for the front, I just wanted to get a little bigger setup. These stock rotors are pretty whimpy, and I will be getting some bigger wheels soon so I figured might as well fill in the gap.

THanks for the info guys!

Will

Should be the J65 prop. valve that came on any 3rd gen with rear disc. You can probably get the pn from your local dealer and then order it from a place like gmpartsdirect.com for about 1/3rd the price lol. Or you could go with a adj. prop valve like the Wilwood piece. I gotta tackle this too when I swap my disc rear in.

The J65 prop valve is what you need; however, GM changed the thread pitch on the prop valve in either 90 or 91, so you need to get a valve with the correct thread. DEFINITELY go by part# for your car's year on this. I.E. if it's an 87 car getting a 91 rear then use the 87 J65 prop valve. This change is what has been causing the myth about needing to swap the master cylinder as well as the prop valve.

Good Sh*t guys! Thanks for all the info. I found a nice posi **** rear with 3.27 gears. I think that will do my application well. I have a buddy that used to work parts for GM and I work for BMW so i might be able to get my parts guy to look into it for me!

Thanks guys

Will

Stainless Steel Brakes may have a kit to do just that. They even had a kit to put rear discs on a 89 Merkur XR4Ti.

..You can use the same J65 prop valve and master cylinder...

Not exactly right. I just did a 1LE swap on my '88 Iroc with factory J65 disc setup. I had to change out both the prop valve AND master cylinder to be correct. In my case, the original J65 prop valve is wrong for the 1LE brake system, and you need the master cylinder from a disc/drum car, which is the same for the 1LEs. Since your car is an '86, you need the "first design" prop valve with 1.0 pitch threads in it. They are different for '89 and newer cars. Check Daniel Burke's page on this.

You have to either get 1LE spindles (good luck) or modify a set of stock spindles by doing a little cutting. It's not too hard if you have access to a band saw (I used a Milwaukee) or have a lot of time and arm strength and do it with a hacksaw. Then you have to get the spindle brackets and caliper cradles, which are also hard to find. Steve Spohn sells a complete kit with modified spindles if you need them, go to www.spohn.net and look in the brake section. It's not a hard swap and is worth every penny. AndyZ28 over on www.thirdgen.org has a CD rom that fully covers the swap in detail with pics of it all. He knows this 1LE thing like no one else I know. As for going with Baer or SSBC, the 1LE system is essentially the same but for less $$$, which is why I did it.


Look on my rebuild page for more info on the brake swap and my suspension rebuild here:

http://photos.yahoo.com/taramiller72

Also, look on Daniel Burke's page for more info and part numbers here:

http://www.ws6transam.org/1LEbrake.html


HTH...

Ed, with 1LEs;)

PS: As for the rears, just swap the entire rear. It's a lot easier than doing a disc /drum swap or the like. I picked up an '89 rear with the PBR calipers and it works great. Plus, you can get one with a better ratio and not have to worry about a gear swap.