Mystery axle noise

[Mastiff]

I recently put a rear Dana 44 from a newer model Scout (seems to match those from 1969 Scout with v8) into my 1965 Scout 80. Everything seems to drive fine, but with the top off I can hear a clickety-clunkety noise from the rear end someplace. I don't know exactly how to describe it, but it's a repetitive noise, not scraping... More like gear engagement or something. Would this be consistent with the gears being set up wrong and needing to be re-shimmed? Is that something that can happen over time? Any other ideas?

I've had it up on jackstands idling in gear and I can't seem to reproduce it that way. The best way to hear it is to coast down hill with the trans in neutral.

I'm going to go poke around at it some more tonight, but I thought I'd see if anyone had any ideas.

 

[ihwild]

I recently put a rear Dana 44 from a newer model Scout (seems to match those from 1969 Scout with v8) into my 1965 Scout 80. Everything seems to drive fine, but with the top off I can hear a clickety-clunkety noise from the rear end someplace. I don't know exactly how to describe it, but it's a repetitive noise, not scraping... More like gear engagement or something. Would this be consistent with the gears being set up wrong and needing to be re-shimmed? Is that something that can happen over time? Any other ideas?

I've had it up on jackstands idling in gear and I can't seem to reproduce it that way. The best way to hear it is to coast down hill with the trans in neutral.

I'm going to go poke around at it some more tonight, but I thought I'd see if anyone had any ideas.

I'm not sure how you would check but maybe you have worn bearings. The other possibility but I'm not sure is some sort of limited slip or locker in the back. I wish I could be more help for you.
Rich

 

[1hc72]

Sound like it might be a locker

 

[Mastiff]

sound like it might be a locker

If it's a locker it's totally destroyed because if it's jacked up and I spin one wheel, the other goes the opposite way. Also, drag from the brakes on one side is enough to cause all drive to go to the other side when I idle it in gear on jackstands.

 

[1hc72]

Id jack it up and rip off the cover and check the gears, but thats just me. Id also check the brakes as well

 

[Robert Kenney]

First, have you removed the diff cover and checked the ring and pinion? Also a good time to see if it is equiped with a power lok. I have a known pl 44 (factory) and the clutches are worn out so it acts open when jacked up.

When in the air are the wheel bearings slopy or rough when spun?

When at it make sure the hubs are torqued enough.

Could also be a loose wheel.

 

[1hc72]

Good advice Robert

 

[RobertC]

Besides what robertk stated --

did you check that the axle tubes are straight / true before you installed it?

Is it possible that there is a piece "brake hardware" loose in the drum?

U-joints?

 

[Mastiff]

The thing was a mess when I got it, so I had it down to the bare backing plates and had the cover off while I cleaned it all out and built the brakes up from scratch. I looked at the gears for obvious stuff like chipped teeth and such, but I'm afraid I could have a mangled locker and I might not even spot it.

When jacked up, everything feels tight at the wheels. This is the biggest reason I discarded my 27,I was sure it needed a rebuild because the tire could be wiggled around. The one thing that seems possibly loose is that there seems to be rotational play when the driveshaft/pinion is turned before it "catches" and turns the axle(s).

Good guess on the loose parts in the drum because I did have that earlier, but it was a different sound. I've had the drums off numerous times since then and I think everything is staying in place. It was amazing that somehow the pushrod from the cylinder to the shoe managed to get out during initial adjustment.

 

[Mastiff]

What would the symptoms be if one or both of the pinion bearings was shot?

I was just at an axle shop for another reason and the guy said it was like a 4-5 hour job to set up the gears. Does that sounds right? It seems like the axle must have been set up right originally, so to get slop in the pinion would require something to wear... Thus my question about bearings.

Robert, you asked about the hub being torqued properly. Do you just mean the lug nuts, or something else?

Thanks.

 

[Michael Mayben]

Charles...from your description of the axle "donor", I gather this d44 is a tapered hub d44 in the "narrow" width as used as an option axle for Scout 80 and in Scout 800. Except the Scout 800 version uses a "centered pumpkin" because of the d20 transfer case used in those rigs. Your d18 transfer case has a different offset as compared to the d20, therefore the already "non-linear" driveline angle of the d18/d27 oem combo is now more severe than the oem setup. That will tend to be kinda harsh on conventional u-joints, I don't care what the "common wisdom" in other forums thinks about that!

U-joint issues/noise are "amplified" by the driveshaft tube...kinda like the body on an acoustic guitar!

Also, those axles were only available with a powerlok limited slip diff, no locker! And there is a "breakaway torque" testing process for checking the clutches/springs in the manual.

So ya need to first verify if indeed the diff is a powerlok setup and go from there.

And it's very common to find the axle drive flange on one side has broken loose from it's taper and sheared the key, even though it appears "tight". So I'd pull both drive flanges (if this is a tapered hub/flange axle) and check that.

The biggest problem is that the axle bearings on these axles need to be "serviced" onna regular basis. When not serviced, the bearing will fail and the outer race will turn in the housing, destroying the bearing bore in the process. The same rear axle in my rig was "repaired" many years ago by brazing up the bore and then re-machining. I have another "tapered" 44 here now in the jig that the housing is destroyed on, someone had used some kind of shim stock to try and prevent bearing race rotation, but that did not work very long obviously!

Some folks claim the bearings and seals for those axles are impossible to obtain...not so! They are on the shelf locally at the supplier I use!

Any of the above ideas can be a root cause for your noise issue. And of course, there is always the "setup" in the ring/pinion/bearing system.

 

[RobertC]

Did you check the backlash on the ring / pinion?

Need a dial indicator -- a pretty expensive tool. My manual states .005 - .009 for a full floating d60 -- a d44 should be silimiar though maybe not the same exact numbers.

Did you rotate the diff using the pinion shaft before you put it back together? Was there "play"?

Another wag -- is the nut on the yoke / pinion shaft torqued correctly? The splines of the yoke / pinion shaft could be worn....

There is a good (though very quick) description of building a differential on the extreme 4x4 Scout buildup...

 

[Michael Mayben]

First off, this axle need to be positively identified and diagnosed!

I'm posting some pics that I May have put up elsewhere over time, but at least this gets everything in one place.

This pic is a powerlok diff inna d44 tapered hub axle exactly the same as the axle we think you are dealing with. This is the 19 spline side gear/axle shaft version used in "early" d44 assemblies. The powerlok is easily id'd because the case bolts together!

You mentioned "slop" in the driveline...that is all kinda normal in dealing with a powerlok, a transfer case, etc. So ya have to narrow down the slop point!

And with the rig on stands and running, there is no weight/load on the entire driveline, so the noise will be diminished/disappear if it's bearing/adjustment/slop-related.

And if ya remove the diff cover, you can certainly fire it up and let the rear axle spin with no oil in there for diagnosis! The gears/bearings are totally slopped with lube anyway, and there is no load on anything! That is an advantage to working with a Dana/spicer axle that doesn't use a dropout pumpkin.

 

[Michael Mayben]

This pic shows using the otc tapered hub puller, the only safe way to pull tapered hubs to prevent destroying the axle flange and brake drum. And sometimes, spot heating of the hub forging must be used along with this puller.

 

[Michael Mayben]

This shot shows the hub/drum removed, the key was completely missing, the hub was simply chattering on the axle taper. You can see the extreme amount of fretting corrosion caused by this and the extreme heat buildup due to friction of the slipping taper.

 

[Michael Mayben]

This is the axle bearing bore in the housing showing how it's been previously repaired inna really nice manner! Took a bigazz lathe to spin that housing for machining!

 

[Michael Mayben]

The driver side of a tapered d44 axle contains the "adjusting" component for proper axle bearing setup. The shims are swapped around until proper endplay is achieved, this takes a while to accomplish, this is all part of periodic maintenance on that type axle.

Axle bearing adjustment is done after the differential is set up in the pumpkin. I use a dial indicator for doing this, but it can also be down with feeler gauges and eyeball if needed. Dial indicator setups are real cheep at harbor freight. And if I drop one and smack it, toss it away and get another one!

 

[Michael Mayben]

Here is a replacement key installed on the cleaned and lapped axle taper. This one shows to be heavily greased so I can pull it off with my hands, this was a "trial fit" deal I had going on.

Once you do the final install, both the axle and hub tapers are cleaned with carb cleaner and dried. Then the shaft is treated with loctite green and the hub final torqued in place. It will never slip/shear again!

Any and all the above can be contributing to your noise issue.

 

[Mastiff]

Thanks for the help. It looks like some of the pics didn't come through though?

 

[Greg R]

The noise appears in coast while in neutral. What's it like when in gear and in coast? Going from easy to hard, I'd check u-joints, wheel bearings, and then gears. If you hadn't serviced the wheel ends, then now is the time to get it done.

that will tend to be kinda harsh on conventional u-joints, I don't care what the "common wisdom" in other forums thinks about that!

That'sa fact jack!
I went from a d20 to a d18 in the 69 800 to take advantage of a warn overdrive deal, and the lower compound low the d18 has. It's 9 years later, and I've gone through 5 sets of u-joints. It don't matter the brand,(I've used the best), or the best grease,(swepco 101), or by the book assemby; there are optimum angles that just can't be achieved with an offset transfer case and a centered diff. It's not the elevation, or the offset alone, it's the resultant compound angle at road speed that kills them.
I've got an offset diff project on the stands now that will go in the 'ol 69. Something to consider if your rig sees road time to the trail.