Semi-catastrophic Rockwell Failure ? Anyone ever seen this?

[rivercreek]

The Patient: M35A3. Brief History: Driving down highway at about 50mph having traveled about 25 miles at same speed. Began to smell gear oil about 3 miles from house and started hearing a noise at about the same time. Stopped the truck, underneath covered in gear oil in plane with front pinion seal on rear axle. Drained fluid - app. 1 qt came out, did have some metal flake and magnet was pretty packed. Note: this failure happened in the last 50 miles. Minor seepage at front pinion seal then, normal for this age vehicle in my opinion. All differentials were checked, full and clean 50 miles and 2 weeks ago. No chunks at all were found in drained remaining gear oil - at least small enough to fit through drain hole. Re-filled diff and drove last 3 miles to get her home. Was quiter but still noticeable gear/bearing noise. Laser thermometer read 255 degrees on top of case just behind rear pinion about 10 minutes after shutting her down. Once she finished dripping gear oil and cooled down a bit, I climbed underneath for a closer look and this is what I found. Attached photos of front and rear pinions, also a photo of front pinion of center axle for reference. The input shaft has been driven backwards 1/2" to maybe 5/8". Have not pulled center driveshaft yet to check to see if front pinion nut backed off allowing this shaft to slide back as it did. I'm obviously assuming at this point, but I'd guess the shaft hasn't broken in half since the distances look to be the same on both side. First question: Has anyone ever seen this? 2nd question: How likely is it that there is catastrophic damage already done and how deep? I plan to tear this axle down just for exploration purposes (curiosity) at some point, but I'm on the fence whether to try and fix this one or look for another used axle. Side Note: I use this truck for snow removal. It's contracted to VDOT for the winter, so a quick repair is essential for me. One last question: Are the gear ratio's in all the A3's the same and are they the same ratio as A2 axles? Just trying to determine how broad my parts pool is. Thanks in advance for any insight.

 

[turnkey]

Might be faster and cheaper to go whole removeable and replacement with winter here...Just a thought.

 

[porkysplace]

The gears from a A2 are the same as a A3 6.72:1 gear ratio. If time is a factor just get a used center chunk and swap it out .

 

[rivercreek]

I'm kind of leaning that direction. Replacement likely the quickest easiest route. Just thinking out loud here but couldn't I pull the rear rear driveshaft, pull both axles and replace the axle caps, allowing me to use the rear axle just as a non-powered load bearing axle? I've never even pulled a deuce non-steer rear apart to know for sure, but it seems to me as though that would allow all the guts to remain stationary and get me back on the road for now. Thoughts? Yes? No? Maybe? Terrible idea? Looking at the diagrams in the TM it seems to me that this would work - i'd just have a 4wd Deuce instead of a 6wd Deuce. A 4wd Deuce is a whole lot better than a broke 6wd Deuce..

 

[brianp454]

As said the 3rd member (differential and housing) of the A2 and A3 are the same.

As you said it is completely ok to pull the drive axles on the rear axle, install a jig on the hub to keep the crud out, and remove the drive axle between the rear and intermediate axle. You can just leave the "bad" 3rd member sit there until you have a replacement lined up. This is part of the advantage of having the bearings packed with gease and sealed independently of the gear oil. Without the driveline and axles installed it just becomes a load bearing axle.

Some guys take the front hubs and machine off the splines to give them a manual method of disabling the front or rear drive without the expense of lockouts. If memory serves I made a 3D model of a cap for the rears. If you have a buddy with a machine shop you can get them made up. Let me know if you want me to send you the 3D files.

Please post pics and share how it failed when you have a chance. It looks like whatever controlls end thrust for that top shaft assembly came loose or failed in some way.

You may want to poke around on craigslist or find one fo the guys that bobs trucks to sell them to preppers. They often have a few non-steering axles piled up. I wouold recommend giving the replacement a good check out and maybe replace the shaft seals on that upper shaft. Good luck!

I'm kind of leaning that direction. Replacement likely the quickest easiest route. Just thinking out loud here but couldn't I pull the rear rear driveshaft, pull both axles and replace the axle caps, allowing me to use the rear axle just as a non-powered load bearing axle? I've never even pulled a deuce non-steer rear apart to know for sure, but it seems to me as though that would allow all the guts to remain stationary and get me back on the road for now. Thoughts? Yes? No? Maybe? Terrible idea? Looking at the diagrams in the TM it seems to me that this would work - i'd just have a 4wd Deuce instead of a 6wd Deuce. A 4wd Deuce is a whole lot better than a broke 6wd Deuce..

 

[rivercreek]

Porkysplace, I hear what you're saying and actually found the whole top loader assembly at Eastern for $450.00 - not too bad moneywise frankly. I had expected it to be more. My concern is how far down the damage is. I'm concerned that the damage may not be isolated just to the top loader assembly. I never heard any deafening Kabooms or Bangs (I've blown apart truck rears before in my day - not anything this big - but one ton truck rears. There's not much question of what happened when you hear/feel that), but as I mentioned - the gear/bearing whine was fairly pronounced during the last 3 miles of my trip - even after topping up the diff with new fluid.

 

[rivercreek]

Brianp454, thanks for the input. It is a big relief to know that I can still keep the truck in service for now by just eliminating driveshaft/axles. This is a really bad time of year for this to happen. I've already got an M923 Cummins 250 torn apart taking up half my shop with a blown #5 cylinder liner. Another plow truck down.. Still waiting on parts for that one... Welcome to my world... I absolutally will post the point/cause of failure of this differential once I pull it apart. I have to say that I'm really curious myself. Theory: Pinion bearing failed due to failed pinion seal/loss of gear oil. As pinion bearing began to bind up at failure, pinion gear tried to "run off" the top of the ring gear, pushing entire shaft backwards. Anyways, just a theory for now. I'll know exactly in a week or two hopefully, and i'll let you guys know. Thanks for the quick and helpful input. I was pretty discouraged a few hours ago.

 

[Wildchild467]

yea, its good to check the oils and not take anything for granted. I blew a bearing on my transfer case on my deuce when I let it get too low. I knew better. The seals did leak a little bit and a long time ago i found a piece of bearing cage on the drain magnet, so I knew it was not 100% (but it worked fine). I pulled it apart, rebuilt it where it was needed, put in a take out upper shaft, one new hub and all new seals. A little oil would save a lot of grief. Take out parts are good and save a lot of time.

 

[zout]

Not much to do with an answer - but when I see a complete thread with no paragraphs my pea brain goes dead and I stop reading. Sentences really really really help put down your thoughts of what your trying to ask and say.

If that is disturbing to read - I have 54 years in the trucking industry as a service manager - service advisor - mechanic and I was starting to read till I got a headache and stopped - only trying to help if I could.

 

[Jeepsinker]

The toploader is one assembly. Pull the shafts, unbolt the toploader assembly, lift it out, drop in the used replacement, reinstall axle shafts, be on your way. Doesn't matter how damaged the old one is because you are not reusing any of it.
What we are calling the toploader assembly here is commonly referred to as a "third member", not to be confused with Goldmember.

 

[rivercreek]

Update: Pulled Rr driveshaft, pinion bearings completely gone. 1/2" or better vertical movement in both front and rear pinions. I wonder where all that metal went ??? So, that's the result, perhaps badly blown pinion seal the cause? I only know for absolute certain that this diff lost all its fluid within the last 50 miles. Anyway, lesson #1 learned: ALWAYS check for fluid puddles prior to departure. Very surprised how quickly this thing happened. Which brings me to lesson #2 I've learned today: NEVER use one's bandsaw to attempt to "NEATLY" cut a 2 1/2 ton Rockwell axle in half. Yes, I should've known better. Still tried. BAD! I've taken the liberty to attach a photo of my attempt at this simply so everyone can point their fingers and laugh at me. If you look closely, you may make out the nick I made in it. LOL. Oh well. Note to self: Stop by Tractor Supply tommorrow and buy new bandsaw blade... Idiot. Confucious say: 2 1/2 ton Rockwell Axle much much harder than Chinese bandsaw blade. Will post photos of inevitable carnage inside diff once I've found and installed a nused one.

 

[rivercreek]

2nd attempt at attaching incriminating photo..

 

[patracy]

For that to be polished like that and the bearings being gone, it's like you said, low on oil. The pinion bearings are the last things to see lube in these axles. So they ate themselves. I'd suspect the gearsets to be worn out as well since the backlash was completely outta whack from the lack of bearings/preload/positioning. I'd just swap the entire third member from a A2 truck.

 

[rivercreek]

Jeepsinker, so what you're saying is that this "Goldmember" is the ENTIRE guts of the differential? There's nothing else that goes in the housing besides that? Looking at the pictures in the TM, it appeared to me as though there was another ring gear below and presumably another set of bearings and races. ?

 

[Jeepsinker]

Third member. And it is all one assembly. The whole top housing will come out with all of the gears and guts in one shot. It is self contained. These axles are simple, you have the main housing, third member, and axle shafts, that's it! No more to it.
The Goldmember reference was a bad pun.

 

[rivercreek]

Jeepsinker, I got the Goldmember pun LOL. I was just kidding about that part. Thanks though, I did not realize that the "Goldmember" was the ENTIRE guts of the diff. As I said, looking at the illustrations in the TM, it seemed like there was more guts underneath it. Live and learn I reckon. Anyways, I don't have but one spare Goldmember and let me just tell you it ain't never gonna end up inside a Rockwell if I have anything to do with it. I've already put the bandsaw to bed and broken out the hot wrench. Kinda made me throw up a little in my mouth to cut those axles, but it couldn't be helped. If the daggone spindles didn't stick out so far, I could have just made a plate and drilled bolt holes to cover the hole into the axle tube, but I haven't got a machine shop handy. I've got to have this girl moving directly, new Goldmember or not. Now the search begins for a replacement Goldmember AND a pair of axles...

 

[jamawieb]

Not much to do with an answer - but when I see a complete thread with no paragraphs my pea brain goes dead and I stop reading. Sentences really really really help put down your thoughts of what your trying to ask and say.

If that is disturbing to read - I have 54 years in the trucking industry as a service manager - service advisor - mechanic and I was starting to read till I got a headache and stopped - only trying to help if I could.

I think most would agree but when someone post a question or report, I don't think it's necessary to critique their typing abilities. Would you like him to take an entire page because he has 10 paragraphs? I think his description is accurate and easy to understand; if you don't have any valuable input, maybe you should keep your thoughts solely to yourself.
I'm sorry that everyone is inferior to you but maybe you should try to help, instead of being inconsiderate.

 

[doghead]

Actually, I agree with his post and it's the rules.

I think he meant it constructively, and even if he did not, you rebutting as you did turns the thread off track and into an argument(that the mods will have to tend to).

Move along.

 

[jamawieb]

From my personal experience, it is easier to replace the rear end, instead of changing the third member under the truck. It would be the perfect time to put a locker in the axle. lol

 

[Jeepsinker]

It is easy if you have the equipment.