Bolt in disc brake and 3.73 conversion?

[Joey D]

I would love for us as a group to identify the exact model, year for the easiest and best upgrade. I'm with Smithville, parking brake is critical, even though I have automatic, it's still a super safety feature.

Any 01 and up GM HD 2500 with the 6.0 gas engine will have the 10.5 axle in it with the disc brakes and parking brake.
The 8.1 and diesel trucks have the 11.5 axle and all single wheel 3500 trucks have the 11.5 no matter what engine, although I can't remember when they came out with the 3500 single wheel truck, 04 or 05 maybe.
You could use the 11.5 with no issues and get the same brakes but I like the 10.5 for the parts availability and it's long history of bullet proof reliability.

 

[guybb3]

I paid about 500 to have them installed. They had to install the ARB at the same time and it adds to the cost vs just doing gears. I use Mitchell Drivetrain for anything gear related as he does excellent work and has done a few other axles for me over the years.

Thanks for the heads up! I have been looking for a front shaft replacement or spline repair. I really would like the newer axle with the discs and wider spacing (I have 2 in. wheel spacers right now) but I have to figure out if getting the axle and changing gears will be cost prohibitive. Is it stupid to even ask if they can change the gears over from my old axle to the new one or are gearsets relatively cheap?

 

[Joey D]

Thanks for the heads up! I have been looking for a front shaft replacement or spline repair. I really would like the newer axle with the discs and wider spacing (I have 2 in. wheel spacers right now) but I have to figure out if getting the axle and changing gears will be cost prohibitive. Is it stupid to even ask if they can change the gears over from my old axle to the new one or are gearsets relatively cheap?

Depending on your mileage you could reuse the gears but I wouldn't chance it. Most shops will not warranty the work if you bring in used gears. The gears and install kits will run you $500. This will give you good USA made gears and timkin bearings.

 

[THEFERMANATOR]

One thing to consider is if you go to the 11.5" rear axle you can then run the TORSEN style DODGE diff in it which is a really nice limited slip unit. Don't know why they make it for the 9.5" and the 11.5", but decided the GM 10.5" didn'nt need one(the 10.5" DODGE version has one though:mad2.

 

[Joey D]

One thing to consider is if you go to the 11.5" rear axle you can then run the TORSEN style DODGE diff in it which is a really nice limited slip unit. Don't know why they make it for the 9.5" and the 11.5", but decided the GM 10.5" didn'nt need one(the 10.5" DODGE version has one though:mad2.

There is already one made, it's called the detroit true trac. Great street diff

 

[THEFERMANATOR]

There is already one made, it's called the detroit true trac. Great street diff

It's not made anymore for the 10.5", or at least that is what they told me last year when I built mine up. My old G80 is NOT happy with the DMAX in front of it, and I looked around for a replacement but couldn't find one.

 

[SmithvilleD]

Since first reading this thread, I've been diligently scanning my local Craigslist listings for this mildly elusive 14 bolt/10.5 ring gear newer axle w/ OEM GM disc brakes. And I finally got lucky (I think). I found a 2004 K2500HD rolling chassis (basically the frame w/ differentials) for a good price. Gotta get it hauled home sometime this week. The truck was a 6.0L gasser, & just as Joey said this model was still using the 14b/10.5.

Just glancing over the front suspension/brakes, I'll have to see if any of those components could be grafted onto my '95? Those forged lower control arms & the front, dual piston calipers look like they'd be nice upgrades although I don't know there's much probability things might just bolt together & be similar/the same geometry.

It also came w/ a MAS sensor that I might be able to use to measure intake airflow on my turbo project. Need to see what that OEM MAS calibration & flow range is?

Joey, are the spring pads you got to weld on, a common/std item? Where did you buy them? This rear end looks to have 2 sets of spring pads OEM welded on (it's using the outer set mated to the OEM leaf springs). I haven't measured my truck's spring center yet to see what's what.

 

[racer55]

One thing I haven`t read mentioned here yet is when changing to rear discs you need to consider that a 4 wheel disc master cylinder needs to be used and the combination/proportioning valve needs to be eliminated if equipped.
There is usually an engineered difference between the front and rear calipers to balance the braking effort also.

 

[SmithvilleD]

Soon as I get it hauled home & parted, I'll measure the piston diameter(s)(calipers & master cylinder pistons & stroke) & see how the area's compare. Then I'll see what might work.

I got the entire rolling chassis in the deal. The front end of the '04 K2500HD has dual piston calipers & rotors that are around 1" larger diameter & a bit thicker than my '95 HD 3/4T's brakes.

 

[handcannon]

I put four wheel disc brakes on my 71 Toyota FJ 40 Landcruiser and love it. I used early Monte Carlo calipers and 90's era half ton pickup rotors and installed a Wilwood adjustable proportioning valve in the rear system. After setting the front to rear balance I am enjoying some really fantastic brakes. You'll love having four wheel discs once they are balanced.

Don

 

[Grendahl]

Joey, are the spring pads you got to weld on, a common/std item? Where did you buy them? This rear end looks to have 2 sets of spring pads OEM welded on (it's using the outer set mated to the OEM leaf springs). I haven't measured my truck's spring center yet to see what's what.

The inner pads are for the bumpstops.

 

[SmithvilleD]

That makes sense. Haven't gotten it home to look it over more closely. Did notice the rear bump stops were different, maybe a bit more substantial. With a bare frame, it's easy to see improvements in the frame that make the newer trucks feel more solid.

Wonder what the chances are of finding somebody that could use a straight/no dmg '04 HD frame, when I'm done scavenging the parts I need? Hate to cut it up & sell for scrap if somebody could use it.

 

[SmithvilleD]

Here are a few quick pics of the '04 6.0L K2500HD 14 bolt/10.5 rear diff w/ dual piston, ventilated disc brakes & integral drum parking brake.

Also took a few pics of that truck's front brakes compared to a rotor & pad to fit my '95 K2500HD's front brakes. The newer brakes rotor is about the same diameter, but thicker w/ notably more mass & dual piston calipers. The newer brakes use quite a bit bigger pad as well.

Don't know if these front brakes can be fit to my '95 but I'm parting the steering knuckles, A-arms, etc. in case it's possible.

 

[handcannon]

Also took a few pics of that truck's front brakes compared to a rotor & pad to fit my '95 K2500HD's front brakes. The newer brakes rotor is about the same diameter, but thicker w/ notably more mass & dual piston calipers. The newer brakes use quite a bit bigger pad as well.

Don't know if these front brakes can be fit to my '95 but I'm parting the steering knuckles, A-arms, etc. in case it's possible

Now that's interesting! I've searched for front brake upgrades for my 94 K2500, unsuccessfully. It seems to me that the dual piston caliper would be way better than the single piston unit. Looking at your pic the pads for your 95 are shorter, but they look like they are wider than the 04 pads, for a wider swept area on the rotor. Also, the hat part of the rotors appear to be different sizes. The rotor hat on the left (95?)is smaller than the one on the right (04?). If so, then if the rotors are about the same diameter, the swept area of the rotor on the right is narrower than the other, which goes along with pad for it being narrower. Just out of curiosity I'd like to compare the sq inch area of the two pads. What are the width and length measurements of the two pads?

I wish I had the parts right in front of me like you have. I'm getting excited about the possibility here.

Are you going to be comparing the two brakes any time soon?

Don

ps--- I just did some quick searching through Rock Auto. For the 04 the front brakes appear to be the same for the heavy 3/4 ton and the 1 ton, just like for my 94. The 04 piston size appears to be 2.25" diameter. This works out to be 7.952 sq inch for two pistons. Compared to the 94 3.15" diameter piston at 7.793 sq inch. The 04 has a slightly larger piston area, but is this enough to give it a big advantage over the 94 piston area?

At this point the advantage to me would be in dual piston vs single piston, and maybe more sq inch pad area for the 04.

What is the mounting bolt distance center to center comparing the 04 and the 95?

 

[Joey D]

Here are a few quick pics of the '04 6.0L K2500HD 14 bolt/10.5 rear diff w/ dual piston, ventilated disc brakes & integral drum parking brake.

Also took a few pics of that truck's front brakes compared to a rotor & pad to fit my '95 K2500HD's front brakes. The newer brakes rotor is about the same diameter, but thicker w/ notably more mass & dual piston calipers. The newer brakes use quite a bit bigger pad as well.

Don't know if these front brakes can be fit to my '95 but I'm parting the steering knuckles, A-arms, etc. in case it's possible.View attachment 25228View attachment 25229View attachment 25230

Measure the size of the knuckle between the ball joints and check the tapper on the ball joints. Maybe you can swap the whole knuckle with the brakes onto your truck. That would be very nice.

 

[SmithvilleD]

It will probably be next weekend before I'll have time to pull the front rotor off the newer setup & get a better pic comparing just rotors. An easy way to compare outer diameter & rotor thickness is go to Summit Racing's site & look up the EBC rotors for our truck & then EBC rotors for the newer trucks. The description gives diameter & rotor thickness specs. The newer rotor is gonna be notably heavier so more mass of iron the heat's going into, so lower temp for a given amt of friction/braking.

I should be able to get a better pic with a tape measure of just the pads in the next couple days. Got a workout stripping down this rolling chassis to bare frame over the weekend.

A while back I saw a website that was selling what looked like just a steering knuckle that claimed it allowed using the newer truck's brakes on the '88-'98's. I'll see if I can find it again & post the link. Could well be they're simply selling the newer truck's knuckle & bearing/hub if the ball joint bolt/taper & geometry is the same as our truck's.

I plan to pull all my suspension apart, blast & powder coat the components, & then button things back together using urethane bushings next winter, so it will probably be a while before I have my stock knuckle & A-arms off to compare. If there are any interested forum members around Kansas City that have an already parted '88-'98 HD 3/4T steering knuckle & A-arms, I'm all for getting together & comparing them to the newer truck's components I have. If it turned out the newer truck's brakes could be a bolt on upgrade, that'd probably be of interest to a number of folks.

 

[SmithvilleD]

Measure the size of the knuckle between the ball joints and check the tapper on the ball joints. Maybe you can swap the whole knuckle with the brakes onto your truck. That would be very nice.

That could make for a pretty sweet & easy upgrade. The hub speed sensor connectors looked similar to our truck's.

BTW - if anybody has a project that needs a low budget set of 4.10 gears, that's what my rolling chassis 9.25 front & 10.5 rear diff have - just shoot me an offer. I'm running 3.73's on my truck so I won't have a use for the 4.10's. I bought this thing as a rolling chassis & obviously haven't driven it, the wear pattern on the rear gears is good/no excessive play, clean gear oil, etc. so I expect the gears are just fine & I wouldn't need much $ for them.

Was happy to find my newer rear-end has the G80 - need to part it & see if it's OK internally. I'm easy on equipment & wouldn't expect to have breakage problems w/ the 14/10.5's G80. If the G80 functions correctly, it should save a fair bit of engaging the front wheels just for a brief slick spot, etc.

The rolling chassis had no visible crash damage. Could well be I'll be able to sell the radiator core support, associated coolers, & straight frame for what I paid for the whole deal. The guy I bought it from bought it on an insurance auction for it's cab/box & figures it was probably a theft recovery as much of the interior was missing.

 

[SmithvilleD]

Here's a link to the site that sells a "brake conversion" kit to use the late model 2 piston brakes on the '88-'98 8-lug K2500's.

http://performanceoilstore.com/products.asp?cat=60

Apparently this swap to the late model K2500 HD front brakes is doable.

Need to study this more, but it appears they're selling the late model's steering knuckle somehow modified to mate to the GMT400/8 lug control arms/ball joints.

I'm not aware that any of our site vendors offer any product that competes with this, although there might be a business opportunity here if the mods to the late model steering knuckle are easy enough to do & a vendor can arrange a cost-effective source for the steering knuckles from salvage yards (although selling used parts may present too many liability issues?).

 

[nobby]

Now that is interesting, thing is SSBC already does a multi piston caliper kit for our trucks. IIRC Tim is running them, perhaps he'll chime in and give a cost comparison. Odds are the pricing is comparable in which case I'd rather go with the SSBC calipers.

Cheers
Nobby

 

[handcannon]

The only dual piston kit I could find was for half ton pickups, not for 3/4 ton rigs.

Don