8 3/4 Rear Disc Brake Conversion

[dickdale]

found this on Ebay: http://www.ebay.com/itm/mopar-8-3-4-dana-60-rear-disc-brake-conversion-/230575563732

for 75 bugs more you do have a emergency brake...

 

[mosquito13]

eldorado calipers and trans am discs. is a true bolt on

found this on Ebay: http://www.ebay.com/itm/mopar-8-3-4-dana-60-rear-disc-brake-conversion-/230575563732

for 75 bugs more you do have a emergency brake...

 

[kb67mopar]

found this on Ebay: http://www.ebay.com/itm/mopar-8-3-4-dana-60-rear-disc-brake-conversion-/230575563732

for 75 bugs more you do have a emergency brake...

That doesn't appear to even be for an 8 3/4 the axle flange spacer is wrong but hey it may fit. I looked at those eldorado calipers, also about the same as a 93 buick Riviera. Not sure of the rotor thickness they use but might be easy to swap to a different caliper and use those. For now I am sticking with what I've got.

To the comment about "enough meat", yes they should be fine, these brackets are more then twice as thick as the scarebird stuff. Also the bolts that go through those holes are going to be welded to the bracket as studs instead making that all one piece again.

Basically I have got so many negative comments about it I think I am going to pass on making them for sale, by the time I satisfy you guys I'll be in the same price range as those already on the market. (hence the reason I started this thread).

Thank you guys for your input. If anybody wants to know how to do this just send me a pm and I'll give you as much info as I can and will even send you my CAD drawings to have them laser cut if you want. Once they are cut out you have to drill and tap the caliper holes yourself, take some more meat off to fit around the axle tube, grind off the head of the bolts you buy and then do some welding to put on brake pad tabs. So its a couple hours in the garage but overall not too bad and depending on your shop cutting these things maybe prices aren't so bad. i got pretty lucky they were testing their machine on my stuff and ended up out the door for $55 with these but typically would have cost me nearly $100 had they not been learning on my stuff.

 

[YY1]

I hope you didn't take my comments as "negative".

Just curious and trying to pass along other info.

I couldn't find any used eldo calipers at the u-pull and remans were over $80 each.
I wasn't keen on gm parts and I didn't want to have to machine the center on rotors each time I replaced them (or machine the center of the axle) at about $50 a pop. 300M rotors aren't real cheap, either.

That's why I sold my scarebird kit. (it was 3/8 as well, but it was a VERY early design).

I was interested in the mustang swap, but I don't really want to move the bearing location.

I thought e-brake provision was in most rear calipers. Not so on the jeep?

 

[old tired rebel]

I think everyone wants to know how well your system works as far as negative comments I haven't seen any. The biggest thing is like you said cheaper than scarebird. You bracket looks beefy enough. And using factory rear disc systems all of them have the E Brake system so how hard can that be hard to figure in. I'm all for it because I have a 8 3/4 rear which I would like to have disc brakes on. I would suggest to you if you want to do this do a step by step build thread here for everyone to see. Also it's not flat here in Oklahoma and E brakes are a must.

 

[kb67mopar]

I didn't mean that any of your comments were truly negative, all very constructive. What I meant was that to really satisfy as a kit I would either need to switch to a different style caliper with e-brake or completely re-design what I have. Unfortunately I just don't have the money to do that.

If I find a way to do it inexpensively I will of course take it on, but right now I don't see it happening. Investors? haha..Don't worry my wheels won't stop turning on this, I am sure I can't leave well enough alone.

YY1, most rear calipers are like these with a mini-drum setup inside which is the jeep setup. The problem lies in being able to mount that inside. It would have to take the place of my spacer plate which may be possible and I will look into probably a little down the road when its not 9 degrees outside.

Old Tired Rebel...don't fret, we can get your car stopped and figure out a parking brake, I'll be running one too, it just won't be "typical". My plan currently is a line lock (or ball valve in the brake line to the rear, pump up the brakes turn the valve and insta-parking brake) but I'd still like a mechanical one too, so I am sure I will keep working on it, though it may end up one off instead of reproducible.

 

[old tired rebel]

I didn't mean that any of your comments were truly negative, all very constructive. What I meant was that to really satisfy as a kit I would either need to switch to a different style caliper with e-brake or completely re-design what I have. Unfortunately I just don't have the money to do that.

If I find a way to do it inexpensively I will of course take it on, but right now I don't see it happening. Investors? haha..Don't worry my wheels won't stop turning on this, I am sure I can't leave well enough alone.

I guess some research is needed. I hate to say if it has to be Chevy parts then make it so. The parts don't know their names or cars they come on. For example Some trucks came from the factory with disc brakes on the rear. My 2002 GMC had them. so there is lots of places to look.

 

[kb67mopar]

I guess some research is needed. I hate to say if it has to be Chevy parts then make it so. The parts don't know their names or cars they come on. For example Some trucks came from the factory with disc brakes on the rear. My 2002 GMC had them. so there is lots of places to look.

I think these would work but without cores would be around $100 each. $200 for the calipers, $10 for pads (cheap) and would probably have to attempt to use the Grand Cherokee rotor. But these calipers should be found easily in a salvage yard...

BUICK	RIVIERA	(1992 - 1993)
CADILLAC	ELDORADO	1992
CADILLAC	SEVILLE	1992
OLDSMOBILE	TORONADO	1992

 

[Budnicks]

Basically I have got so many negative comments about it I think I am going to pass on making them for sale, by the time I satisfy you guys I'll be in the same price range as those already on the market. (hence the reason I started this thread).

Thank you guys for your input.

Don't let a few negative comments discourage you, keep up the good fight... march on soldier...LOL...

- - - Updated - - -

I don't disagree one bit, my only issue is I have to have enough interested parties to make it worth any additional investment here. Just doing it the way I did it in one off form just the laser cutting is around $100 for one set. So quantity starts to reduce price and finding somebody with the ability to bend 3/8" plate the way I want might be a bit more expensive then its worth. Also adding in a parking brake would be another expense which would have to be justified. I can't go out and spend 1k making a package only to have 3 guys buy it because the rest like their drums... I suppose this is why nobody really makes kits for less than $500.

I understand completely< I was referring to down the road mostly, only if you got enough interest to "do a run of them" & cheap enough, you really need a buddy with equipment/machinery...LOL... that always helps, for costs.... cheaper & easier rear disc brake conversion deal, it's been tried allot, I commend & welcome your efforts & for sharing with us & putting up with all the advice & crap from all us damn "know it alls"...LOL.., I think most posters here are honestly, just trying to help, with good intentions, not to be a kill joy, but something you may want to think about also, brakes & parts/safety equipment,could also bring in allot of personal liability issues on you, if they were to fail... there's some very unscrupulous suit happy people out there, nowadays... you need to protect yourself, 1st & foremost, no matter how much you trust anyone, if you plan on producing something in a large quantity &/or just sell them a dozen or 2 only in lessor numbers... don't get discouraged, you need to be aware of all aspects... have fun & keep up, continue the great work, march on soldier...LOL...

 

[YY1]

Yep, one year only and no they're not easy to find.

I go to three different u-pulls about every six weeks, and two more a bit less frequently.

In the several years (2002-2008 IIRC, which should have been prime time for those being 10-15 years old) I was holding those kits and contemplating the swap, I saw exactly ONE donor car, and one caliper was missing from it.

Now that IS a negative comment, but not on the OP's adaptor project.

 

[kb67mopar]

Thanks guys. Don't take it the wrong way, nobody discouraged me from my efforts. It has just been abundantly clear that to get what everybody looks for in a brake kit I will be on par with current kit costs and really no savings there.

I'll keep looking at it and like I said I still want to look into a parking brake for myself. I am thinking about a driveshaft brake...haha the wheels never stop turning do they! And when it gets decent enough outside I am going to see if I can acquire some brake parts from the local salvage yard.

 

[mosquito13]

i did need to buy shorter bolts for the bracket. ones supplied were 1 1/4" too long. eight bolts . other then that really was super ez with good directions with diagrams written by someone who's native langue is english. wish it was ma mopar but the parking brake was mandatory. sprayed the whole thing with diamond coat, not that anyone else will see it with the steelies. damn thougt i was adding this on to the pics. no delete option?

 

[dickdale]

Don't let a few negative comments discourage you, keep up the good fight... march on soldier...LOL

My 2 cents! That's whats separates the men from the boys... :headbang:

 

[Supershafts]

Im not being negative, BUT if you are going to sell these you NEED to test that brake upgrade in all kinds of situations and you should rent a road course for a day or so and really you need to hammer the hell out of it...

Here is why, if you sell them and a guy like me buys them who drives or races everything you need to know the heat fatigue on that bracket and the weld won't fail... These are problems you can have.

You really need to test that at all kinds of speeds repeatedly and really over work that so if it does have a failure you can fix it.

 

[snakeoil24]

Rear drum brakes work better than using discs. Save your money. With 70 percent of the laod on the front brakes, having the mix of rotors and drums you get a far better track and brake performance.

 

[Supershafts]

Thats not true snakeoil, 1st lap on a road course with disc and drums and you are really driving it, the 2nd lap you are NOT hitting the brakes at the same location entering the turn you will be on the pedal earlier.

 

[RustyRatRod]

Drum brakes are theoretically more efficient than discs......but they are not. If that makes sense. Compare the surface area of drums VS discs. IF there were a way to make drums as efficient at changing energy of motion to energy of heat, drums would win hands down. There are some companies that offer HP drum setups. Dirt track racers use them in certain classes. Think how much lighter drum brakes are. The weight difference is staggering. To my knowledge, no one has made drums as efficient at converting energy of motion to energy of heat. If they ever do, you'll see drums make a comeback. I'm not sure that's possible though.

 

[Supershafts]

Drums are way lighter, they just don't stop after a bit. Braking is also a area that can hurt performance, it's great to add big 14" rotors and stop quicker, but the weight of the rotor and the wheels to stick them in there are a issue. There are the lighter set ups that use the AL hats and they are lighter.
On a drag car we always kept the drums until it became a issue of stopping as most guys will admit of what happens when you get into the single numbers and you have 4 wheel drums, they work at the 1330 ' mark. . . .they go away as quickly as you covered the 1320

 

[RustyRatRod]

Yup, brake fade is their biggest drawback. It's kinda sad considerin how much more contact area they have compared to discs. lol

 

[YY1]

I thought the one of the main advantages of disks, besides better heat disspation, was that they were able to do the same work with a much smaller contact area.