1962 GMC 4x4 Front Axle with disk brakes.

[JPBrecheisen]

I've searched this forum and have seen most recommend swapping the entire front axle to something 73 and later if wanting disk brakes. I don't wish to do that, but the latest project I'm working on has had some "upgrades" to it already. Its the original closed knuckle set up, but PO had somebody put disk brakes on it. The disk brakes appear to be off an early Dana disk set up. I've read a few articles already about the differences in u-joint size, spindle length, and outer axle stub length....So here is my issue. Brakes work fine. But the knuckle seals need attention. So i started pulling everything apart. First thing i noticed when taking of the locking hub is that the axle stub doesn't protrude out past the locking hub insert to allow for the small snap-ring to be put on. Next thing is, the axle has literally no end play at all inside the spindle. I am used to these things having some end play with the outer axle snap ring installed. Anyway, I continued disassembly and once I go to the spindle and backing plate bolts off...the outer axle stub is "stuck" inside the spindle. It rotates freely, but I can't get it off. I don't see any form of retention clips of any sort. Here are some pics so you can see what I'm talking about. I sort of have a feeling the spindles and backing plates were swapped as they will "bolt on"...however I don't think the axles are the correct length. I read an article and it clearly showed the axle stups for a factory disk brake set up a a smidge longer than those that were factory drum brakes. Any tips or ideas would be helpful. I'm not opposed to the disk brakes at all...but I also want to un-frankenstien this thing so its the way it "should" be. Thanks in advance. I put the picture of the backing plate on so maybe hopefully somebody will know about what year these things came off of. The PO said "70 something".

[JPBrecheisen]

I wanted to explain the "stuck" spindle thing a little better and include the link to the article for the disk brake swap. When i unbolt the backing plate and spindle from the knuckle...the spindle pulls the whole axle out of the housing...but the axle spins freely inside the spindle...not sure whats going on. I looked at the back of the spindle and I don't see anything holding it in there. I wanted to ask before I try to start separating anything with some "force".

http://www.4wheeloffroad.com/techart.../photo_06.html

[JPBrecheisen]

Here is a picture of what happens when I pull the spindle off the knuckle...the whole axle comes with it..and I can't really pull them apart.

[JPBrecheisen]

No takers on this one I guess?

[rcbildr]

Sounds like it might be a press fit, but I've never worked on a closed knuckle front end before.

[maxwoof]

I don't see how that spindle can be attached to the axle stub that way. Is there any play there? I had my closed knuckle apart not too long ago, and nothing unusual like this. The picture kind of looks like the spindle has a weld on it? I'm stumped too.

[JPBrecheisen]

Yeah, I've not seen it before either. The "weld bead" you're probably seeing is some grime that has been since cleaned off. I'm going to go ahead and get the axle out and see about getting then separated. Its just so strange how the axle can spin in there with no problems but be stuck in there at the same time. Talking to John at RandP 4WD, he seems to think possibly the bushing/bearing might have a groove of some sort thats catching but doesn't think it will be a big deal to get it appart.

[maxwoof]

There may very well be a bushing in that spindle. Now that I think about it, I seem to remember a bronze bushing in there. I remember it because it was different fro the last axle I had apart - an 85 K-20 - which had a needle roller bearing in there. Maybe, the bushing got stuck to the axle, but spins in the spindle? I would be ineterested to find out. Good luck

[DirtyLarry]

I’ve seen happen before. There is a cage bearing inside the spindle towards the back where the axle goes into it, not a bushing in these old closed knuckle axles if I recall, and when it is dry it seizes to the axle shaft. Give it a good whack with a dead blow hammer and it should pop loose. The axle shaft stub maybe ruined if it is seized that badly. Been a LONG time since I’ve been into a closed knuckle axle. Odd how they added disk brakes to a closed knuckle axle as I too would have suggested installing an entire later open knuckle axle to get disks.

[JPBrecheisen]

Hey Guys,

Thanks for the input and information. I was also talking to John and Paul at R&P 4WD out in Orgeon City, OR and they said almost the exact same thing. I sent them some pictures to try and help identify these spindles and brakes. They say the spindles are a 74-76 1/2 GM half tone disk spindle....which has a bearing on the inside of the spindle that could have gotten siezed in some manner to the outer shaft. I will be removing the axle this weekend and trying the dead blow hammer, or a press if needed to get the 2 apart. I talked with them a bit about the "disk" conversion, and they also said that on an early closed knuckle 44, that is the best way to put disk brakes on it. I'd still like to find some original drums, hubs, backing plates, and spindles so I can have parts to go full original at some point. I'll keep you posted when I get the spindle/axle separated. Thanks again for the tips.

[JPBrecheisen]

Okay, So here is an update. I set the spindle back in the knuckle and with about 3 swift hits with a big dead blow hammer, the axle popped loose from the spindle. I removed the spindle and found the following:

There is in fact a needle bearing on the inboard side of the spindle as I was told to expect. It is damaged, and obviously in need of replacement....but I don't think its because of age. I believe that its because the other shaft bushing/bearing shoulder/race is too big for the ID of this bearing. Its kinda hard to see in the pictures, but the inboard face of the bearing is all caved in. If you look at the very outer edge of the bushing/bearing race on the outer shaft, you'll see a bright colored ring. Thats where the outer shaft was "forced" into the bearing...and thus caused it to be "stuck" on. I also believe this is what caused the damage to the bearing..the cage is wasted....So I will take measurements etc, but it still appears I don't have the right combination of items for this disk brake set up. I'll try to see if I can't find a bushing or bearing that will fit for this application, but I'm kind of skeptical at this point. Anybody have some drum brakes off a closed knuckle they want to sell???

I posted some pics so you can see and follow along. Send advice or tips as you are inclinded.

Thanks.

[DirtyLarry]

Glad you go it apart easily but I got nothing else to add to your dilemma but I suspect that you are correct in that the closed knuckle/drum brake axle shaft may not be compatible with the disk brake spindle. If you are going for originality with this truck, you would be better off locating drum brake pieces as you mentioned or……locate a complete disk brake front axle with the correct gear ratio to swap in. Not sure what kind of bag of worms that presents with spring perches and steering connections.

Good luck with your project. I wish I could find a 60-66 4x4 to add to the nest. I looked up a picture of your truck in a different thread. Great looking machine!

BTW….welcome to the best GM forum on the web!

[JPBrecheisen]

Thanks for the help, and the welcom. I like this forum quite a bit. Its been helpful so far.

I found this truck not too long ago. I have been working on a 65 long bed 2WD for a while. I kinda like the 4x4's, but the 60-66 types are hard to come by.

I'd like to go original to be honest, but I haven't been able to locate parts yet. Most seem to send the old closed knuckles to scrap. I like the disk brakes and all, but the old drums stop ok when they're adjusted correctly and have good quality shoes etc. I've kinda always found it easier to keep things stock since you know what parts go to it. Until I was able to identify the spindles I didn't know what calipers/pads/bearings I would need to get it fixed.

I spoke with the guys at R&P 4wd again and they suggesed getting .015 taken off of the bushing/bearing race on the outer shafts so the outer stub will fit inside the spindle bearing. They seemed to think that would be the easiest way to do it. I think if I get that done, it may all work out pretty well...hopefully. I'd sort of rather just put drums back on it so I don't have to "cut" anything, but I guess we'll see.

Anyway, thanks for the help and the welcom to the forum.

Jonathon

[JPBrecheisen]

For anybody thats following along or cares, I'll make a few more updates.

So I got the knuckle all the way aparts so I can replace the ball seal and the trunion bearings. The ball has some damage from years of dry/dirty usage. I have a plan to get it repair. What I'm going to do is use some JB weld epoxy (original formula). It takes longer to cure, but its much stronger. What I'll do is mix it up, then paste it into the grooves that have been cut on the ball, then fair it down with a strip of emory paper. I've done it before, and it works pretty well, so the new seal will have a nice smooth surface to seal against. Its kinda like doing body work on a knuckle ball.

I talked some more with Paul and John out at R&P 4WD in Oregon about the compatibility issues with these disk brakes on this closed knuckle drum-original axle. The reason the spindle was stuck was because the newer spindle bearing ID was smaller than the bushing/bearing race on the outter axle stub. They recommended that I take the outter stubs off and have a machinist take about .015 off the axle so it will fit inside the spindle bearing.

I'm still looking for some original parts to go back to stock, but no luck so far. I have no issues with drum brakes as I usually don't take my old 4x4 stuff above about 55 mph. The guy that had this truck before complained it wouldn't stop really well, but after looking over the back brakes..the wheel cylinders weren't even replaced..and they're frozen and leaking...no kidding the thing wouldn't stop.

Anyway if anybody has wheel hubs, backing plates and spindles, let me know. I can get the rest of the stuff aftermarket, but I'd rather go back to drums than cut more original stuff.

I posted some pics so you guys can watch the progress.

Jonathon

[maxwoof]

I agree with you in that I like the original closed knuckle axles. A lot of people don't. I see posts from time to time here where people are swapping them out, so keep an eye out and maybe you will come across one. Also, I think they may have been used in other trucks of that era, check eBay and craigslist as well.

I think you have a good idea as to how to fix up that scored knuckle. Even so, they are prone to leaks. Back in 2009, when I rebuilt mine, I packed all the associated bearings like conventional wheel bearings that you would find in a typical open knuckle. I don't put any oil in the knuckle, I just occasionally wet down the wiper seal. So far, so good. When I took the knuckle apart, the wheel bearings were very dry, and the knuckle bearings were destroyed from lack of lubrication. The grease won't run out like the oil. Something to think about when you get there. Good luck, and thanks for the pictures.
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[JPBrecheisen]

I agree maxwoof. I just think its kinda nice to see them once and a while when they have the original equipment under them. I am still looking for parts, but leads are slim at this point. It seems like everybody that I have called has recently scrapped what they had. I do have a lead on 2 parts truck that may have some items of use. I don't disagree with the open knuckles being better, but this truck is almost 100% original, so I'm gonna try to keep it that way if possible. I've done the same trick you've talked about with the closed knuckles on my Willys wagon. There is special lube that is supposed to go in them...its really heavy, but still fluid. NOVAK sells the stuff. Its supposed to be heavy enough to the point where it won't leak out, but liquid enough where it still slings to lube the trunion bearings and u-joint. When I did my willys, I just put a bead of grease on the inside of the felt seal when I put it togther and made sure the u-joints were greased really well before I installed the axles. I used a needle fitting to make sure they were nice and full. That vehicle doen't go over 10 MPH when in 4x4, so I don't think it will sling out. I also packed the trunion bearings just like I would with a wheel bearing. I think it will work. So far it has. Thanks for passing on the tip though. I appreciate it very much.

I did find some extra outer axle stubs from R&P 4WD out of a ford and they are going to mill down the spindle bushing/bearing race as discussed in previous post so they will be compatible with the disk break spindles. I didn't want to cut the original axles and want to have them set aside when I do come across some hubs/drums/spindles etc.

Here are some pics of the axle bell/ball repair. Its JB Weld original formula metal epoxy. Takes time to cure, but it works pretty well. I pasted it in, let it dry, then started with 220 grit then on to 320 grit. I had to apply a bit more in a few spots, but so far so good. Once its painted, there will be a nice smooth surface for the seal to slide on.

[Ridgeback]

If you are interested, post your email and I will send you a copy of the Dana Spicer Maintenance Manual that contains the closed knuckle axle.

[JPBrecheisen]

I think I might have them already. Does it say Spice Axle on the cover, and say model 44 on it with the "44" being really huge?

Send me what you have anyway. JPBrecheisens@aol.com


Here is how my closed knuckles should look when they're all done. This is the work I did on my Willys about 2 years ago. I don't have the "spicer joint" tags on this one though. Maybe I can find some eventually. I think most repair shops tossed them out when they did seal work.

This is a model 25 axle with the lockheed style drum brakes which is what belongs on the axle under this 62 GMC.

[JPBrecheisen]

Ridgeback,

Its JPBrecheisen@aol.com

Sorry, the "s" at the end of my name was a typo.

[MikeS.]

JP, I'm sorry I couldn't help you out with my old 63 axle. TAlk about a day or 2 late.

[JPBrecheisen]

Originally Posted by MikeS.

JP, I'm sorry I couldn't help you out with my old 63 axle. TAlk about a day or 2 late.

MikeS,

No worries. It happens.

Jonathon

[JPBrecheisen]

Originally Posted by Ridgeback

If you are interested, post your email and I will send you a copy of the Dana Spicer Maintenance Manual that contains the closed knuckle axle.

Rideback,

Got the manuals. I only had 1 of the 4 you sent. I'm sure they'll prove helpful in the future. Thanks for sending those my way. Alawys good to have info on these things.

Jonathon

[argonaut]

Dude, I would have given you the entire closed knuckle dana44 that i pulled out of my 66. But no one wanted it so it went to the scrapper...

I think at this point you should use what you've got and get a few things machined to fit correctly where necessary. Then just maintain it and it will last as long as you do! And you'll be the only one on the block with a disk brake closed knuckle front axle!

[JPBrecheisen]

Originally Posted by argonaut

Dude, I would have given you the entire closed knuckle dana44 that i pulled out of my 66. But no one wanted it so it went to the scrapper...

I think at this point you should use what you've got and get a few things machined to fit correctly where necessary. Then just maintain it and it will last as long as you do! And you'll be the only one on the block with a disk brake closed knuckle front axle!

Man, thats a bummer. I seem to be tracking down folks that just got rid of their old one.

I am still looking for original parts, but in the mean time, I'm having a set of extra outer axle stubs machined down so they will fit inside the I.D. of the inner spindle bearing. After that is completed, most every thing should fit and work pretty decent. Once I get the stubs arrive, I'll post pictures etc so anybody that is interested can follow along. I'm out of town this week, so I've not had a chance to get it started.

This truck is so close to original, I'm trying to keep it that way, but as long as it works (correctly) is all that matters.

Jonathon

[Erl]

I have an original 63 front end. Send me a private message with your phone number.

Erl