K20 - big hub axle swap. Disk brakes help

[Krex]

Ok everyone I hope some one out there can help.

I have a big hub external spline Dana 44 on my 1970 k20. It also is open knuckle. I checked the axle code to confirm its oem to the year with the 4.10s anyway.

I also have a 76 Dana 44 from a 76 k20 internal spline hub open knuckle with 4.10. Also this was a auto locking front axle.

So the plan was to swap the 76 under my 70 and bolt everything up so that I could have disk brakes. But first I wanted to open up the 76 check replace ball joints etc and put in manual internal locking hubs.

Here is the PROBLEM. During disassembling I found that my small hub spindles were shot and would need replacing... So I looked around for new spindles. Found out very quickly that everything is out of my price range at the moment because I need to buy the internal locking hubs too. I only want new btw if I were to buy.

So the QUESTION is... For disk brakes what do I need for a the big hub big spindle external locking hub Dana 44 or do I have all the parts already. Can someone make me a list?

What I have:

76 Dana 44
76 rotors
76 brake calipers
76 rotor backing plate.
76 small hubs
76 small spindles (bad cannot use)
70 Dana 44
70 drums
70 brake shoes
70 drums backing plate
70 big hubs
70 big spindles
70 external locking hubs external premium spicer
72 3/4 ton brake booster
72 3/4 ton master cyclinder
72 3/4 ton prop valve

Again please provide a list for a big hub Dana 44 disk setup parts. Thank you

[jeffahart]

Well, that list makes it a bit confusing. Let's just say you have a complete axle.

Really all you should need is the locking hubs and new soft lines and steering damper.

So what about your original brakes. Were they not power? Because you can skip this.

72 3/4 ton brake booster
72 3/4 ton master cyclinder
72 3/4 ton prop valve

Here's why. If your not good at brakes or have a fair amount of experience you could become frustrated.

I would use the original booster, original master, original prop valve. Remove the residual pressure valve from what was the front drums.

Now you can run the vehicle and have a bench mark for how it brakes. Then start replacing/upgrading brake components.

Big bang parts changes, where everything gets changed at one, makes it hard to trouble shoot, prop valve/distribution block/booster/cylinder/disc/drum combos, as to what's causing problems. And it is unlikely in my eyes that you will be happy with how it brakes on first pass.


Also, check your front pinion angles before and after swap. Just as a sanity check to make sure nothing changed there.

Anyhow the swap should be pretty straight forward.
Have fun... it's a fun upgrade moving up to disc front.

[kwmech]

You would have to come across a couple of disc brake, bolt on locking hubs, wheel bearing hubs. Not available for years now. You may have to suck it up and buy new spindles, seals, (assuming the wheel bearings are good) and a set of 20990 locking hubs

[Krex]

Originally Posted by jeffahart

Well, that list makes it a bit confusing. Let's just say you have a complete axle.

Really all you should need is the locking hubs and new soft lines and steering damper.

So what about your original brakes. Were they not power? Because you can skip this.

72 3/4 ton brake booster
72 3/4 ton master cylinder
72 3/4 ton prop valve

Here's why. If your not good at brakes or have a fair amount of experience you could become frustrated.

I would use the original booster, original master, original prop valve. Remove the residual pressure valve from what was the front drums.

Now you can run the vehicle and have a bench mark for how it brakes. Then start replacing/upgrading brake components.

Big bang parts changes, where everything gets changed at one, makes it hard to trouble shoot, prop valve/distribution block/booster/cylinder/disc/drum combos, as to what's causing problems. And it is unlikely in my eyes that you will be happy with how it brakes on first pass.


Also, check your front pinion angles before and after swap. Just as a sanity check to make sure nothing changed there.

Anyhow the swap should be pretty straight forward.
Have fun... it's a fun upgrade moving up to disc front.

If i only need, locking hubs , I think you mean i need new spindles and locking hubs.

I had manual brakes before I recently upgrade manual to power brakes. I was just listing this so that everyone knows I am already power brakes.

I am pretty good about brakes. I would figure this out but it's a daily driver and did not want to brake it down then figure out I need parts, and no truck on the road.

Already have the new booster and new master cyc. and prop done. that was easy.

Power to manual was a huge upgrade to me. This drum to disk is not all about performance. It more about adjustment to the brakes, not hearing my cermic brakes squeal. Before I get them warmed up.

[Krex]

Originally Posted by kwmech

You would have to come across a couple of disc brake, bolt on locking hubs, wheel bearing hubs. Not available for years now. You may have to suck it up and buy new spindles, seals, (assuming the wheel bearings are good) and a set of 20990 locking hubs

I am a little confused on the answer this is what I was planning to do to see if they work. But I did not want to try unless its do able since its a daily, of course I can put it all back together if it does not work.

remove everything down to the knuckle on the 1970 k20 (drum axle)

list from inner knuckle to outer
70 axle still under truck
70 axle shaft
76 disk shield/ caliper mount
70 big spindle
76 rotor
70 big hub
70 external locking hubs
76 caliper

Would this work or no

[jeffahart]

You're right, I glanced over your spindles are shot.
OK you have power brakes. Drum Drum. you still have considerations on the Disc Drum upgrade or change or whatever you want to call it. You still need correct setup. I was just suggesting removing the rpv.

You may want to consider a different axle. Because I think the parts list might start ringing the register with spindles, locking hubs, bearings, seals ect.... Plus since it's your daily driver I think you might be able to scout a D44 as a take out and just pop it in with just a few parts and one days work.

Good luck!

[kwmech]

Originally Posted by Krex

I am a little confused on the answer this is what I was planning to do to see if they work. But I did not want to try unless its do able since its a daily, of course I can put it all back together if it does not work.

remove everything down to the knuckle on the 1970 k20 (drum axle)

list from inner knuckle to outer
70 axle still under truck
70 axle shaft
76 disk shield/ caliper mount
70 big spindle
76 rotor
70 big hub
70 external locking hubs
76 caliper

Would this work or no

No, for 1, the knuckle/spindle bolts are indexed differently for the drum backing plate (1970 only). Now you are changing knuckles or you could re-index the backing plate though, if you feel like drilling 12 holes. I think the 70 also had the smaller 260 u-joint. I don't think you can mount a rotor onto a drum hub (never tried though)

[Krex]

Originally Posted by kwmech

No, for 1, the knuckle/spindle bolts are indexed differently for the drum backing plate (1970 only). Now you are changing knuckles or you could re-index the backing plate though, if you feel like drilling 12 holes. I think the 70 also had the smaller 260 u-joint. I don't think you can mount a rotor onto a drum hub (never tried though)

i forgot to say i do have backing plates form a 1972 dana 44 as well. Do you think theses will work? to fix indexing, Or I will have same problem. I dont mind welding up the hole in the backing plate and drilling some new holes.

[Krex]

Bump still looking for help

[ND_guy]

I have a set of D44 spindles here but I can not recall what I got them off of. Tell me the dimensions of the spindle you need and if they are correct you can have them for the cost of shipping.

[Krex]

Originally Posted by ND_guy

I have a set of D44 spindles here but I can not recall what I got them off of. Tell me the dimensions of the spindle you need and if they are correct you can have them for the cost of shipping.

Thank you here are the dimenisions

Total length to base 5 5/8
Center hole from top 1 1/2
Top to first little angle out 1 15/16
First angle out to 2nd angle out 1 1/4
2nd to 3rd 7/8
3rd to base about 1

All measurements are not exactly but eyed with ruler quick this morning.

[kwmech]

It's easier to swap the steering knuckle out. The only difference is the steering tie rods..... and whether or not the tie rod comes up from the bottom or down from the top.

[kwmech]

Spindles for a chevy......I think this is where some things are getting confused. For the chevy applications there were essentially only 2 spindles.

706528x this is the small bearing spindle early 1/2 ton, this spindle took an inner bearing of a 603049.

706529x Early large bearing, took and inner bearing of 368 (2'' i.d.) this spindle is 3/4 ton, took the hub with the 'bolt on' locking hubs that what most people refer to as the HD 44 because the axle tubing was almost 3/4'' thick.

706570x This spindle was the fit all when Dana or GM went to the 10 bolt front end, (may have been a year or so sooner), anyways, this spindle fit both the 1/2 ton and the 3/4 ton. Took an inner bearing of 104949. The 104949 and the 368 share the same inner diameter of 2''. How about that?


All of the outer bearings remained the same through out the years along with the spindle nuts, All of the seal diameter surfaces were the same at 2-1/2''. Seals were different in that some of the hubs were different due to the bearing that was in the back.



So, you can go down to the wrecking yard and grab a set of spindles off...say a 1985 and they will work.



All of the lengths are the same, all of the bolt patterns are the same. There were/are some small differences in the back of the spindle on the early stuff in regards to how the stub shaft sealed to the back of the spindle along with the thrust washers.

[Krex]

Originally Posted by Krex

Thank you here are the dimenisions

Total length to base 5 5/8
Center hole from top 1 1/2
Top to first little angle out 1 15/16
First angle out to 2nd angle out 1 1/4
2nd to 3rd 7/8
3rd to base about 1

All measurements are not exactly but eyed with ruler quick this morning.

I have the tie rod and the knuckles from both the 70 and the 76.

I also checked the small spindle pattern this weekend for fitment on the 72 caliper support and the 76 caliper support.

Also the 70 (71) big Hub and the 76 big hub on http://www.quad4x4.com/category/GAX0...e-Parts/1.html

Appear to be the same and the 71 and 76 take the same 13 inch rotor.
The 70 and 71 and 72 are different by just drums.

So I believe my big hub should attach to the rotor and be the right size and fitment.

The only thing I may have to use is the axles shafts form the 76 since the website says it's a little longer.

What does everyone think?

[Krex]

Originally Posted by kwmech

Spindles for a chevy......I think this is where some things are getting confused. For the chevy applications there were essentially only 2 spindles.

706528x this is the small bearing spindle early 1/2 ton, this spindle took an inner bearing of a 603049.

706529x Early large bearing, took and inner bearing of 368 (2'' i.d.) this spindle is 3/4 ton, took the hub with the 'bolt on' locking hubs that what most people refer to as the HD 44 because the axle tubing was almost 3/4'' thick.

706570x This spindle was the fit all when Dana or GM went to the 10 bolt front end, (may have been a year or so sooner), anyways, this spindle fit both the 1/2 ton and the 3/4 ton. Took an inner bearing of 104949. The 104949 and the 368 share the same inner diameter of 2''. How about that?


All of the outer bearings remained the same through out the years along with the spindle nuts, All of the seal diameter surfaces were the same at 2-1/2''. Seals were different in that some of the hubs were different due to the bearing that was in the back.



So, you can go down to the wrecking yard and grab a set of spindles off...say a 1985 and they will work.



All of the lengths are the same, all of the bolt patterns are the same. There were/are some small differences in the back of the spindle on the early stuff in regards to how the stub shaft sealed to the back of the spindle along with the thrust washers.

Attached is a 76 spindle that looks like mine but mine.

[ND_guy]

Krex, the spindles measure
2.5 at the seal surface.
1.99" inner bearing diameter
1.60" outer bearing diameter.
Aproximatly 6" tall from knuckle suface to end of spindle threads
1.624" bore where the axle stub shaft bearing goes.
I got these over ten years ago and they have been in the shed ever since. Some surface rust but will clean up with emery cloth if you decide to take them

[Krex]

Originally Posted by ND_guy

Krex, the spindles measure
2.5 at the seal surface.
1.99" inner bearing diameter
1.60" outer bearing diameter.
Aproximatly 6" tall from knuckle suface to end of spindle threads
1.624" bore where the axle stub shaft bearing goes.
I got these over ten years ago and they have been in the shed ever since. Some surface rust but will clean up with emery cloth if you decide to take them

Those seem like they would work. I would like to give them a shot. Send me a pm with shipping to 75023