Rear Axle rebuild

[The_Handier_Man1]

From: Jupp318  (Original Message)
Sent: 7/16/2006 3:02 PM

Some time ago I asked the question whether the Spicer 60HD axle is the same as the Dana 60.  Well I still haven't managed to get an official answer but I have found a web site that at least gives some insight to the question. The website is http://www.autohobbydigest.com/dana.html  and it lists all sorts of identification info.

Once I get some definitive information I will add it to this discussion.  The reason I need to find an answer is that I need to take a look at the rear end as I believe one of the pinion bearings to be on the way out (a screaming sound on coast at about 60 MPH).  Once I can find out if the axle is the same as a Dana 60 I can get the parts required to fix it.  Also as I have not been able to find any grounding straps between the Engine/transmission to the chassis I am beginning to suspect the reason for the bearing damage may be that the electrical return path is through the axle via the prop shaft.  Anyways I'm about to fit 4 big straps across the engine and transmission mounts just to make sure things are well bonded.

Cheers Ian...



From: DanD2soon
Sent: 7/16/2006 4:06 PM

Hey Ian,

This link:  Dana 60 Axles http://medusa.ih8mud.com/cruiser/D60HD/D60.html  discusses differences between the "60" & "60HD" near the bottom of the page.  Mostly having to do with the "60" having a 1.3" diameter axle with 30 splines and the "60HD" having a 1.5" diameter axle with 35 splines.  Hope it helps.

Incidentally, about your grounding strap strategy;  A single good current path to ground is much preferable to several current paths - in other words - one good motor mount or transmission mount shunt strap is better than four at varied locations! (has to do with ground loops) So, in this case, the easier way is the better way.  If the ground strap material you're using is not as heavy as you'd like it to be, run parallel straps of equal length between common attachment bolts.

Good Luck,
DanD



From: denisondc
Sent: 7/16/2006 6:35 PM

I presume you are sure the shrill noise is not one of the universal joints?
I still think the axles in our motorhomes are different from the Dana axles going into todays 4 by 4s, because the track width (where the wheels run) is probably greater, hence a slightly longer axle housing; and other differences due to being made 30 years ago.
But as for getting the correct parts - if you are going to do the work yourself, werent you going to take it apart first? It is quite a job to do this stuff, even after the axle is off the vehicle. To me it is more trouble than rebuilding a V8, maybe because I dont have some of the special tools needed. I did have a case-spreader to help me when I did it to a 52 Ford F1. If either pinion bearing is bad, I think you replace both of them. The number that is on the bearings is all you would need to know to get new ones around here. Same for the pinion shaft seal.
The service manual goes into detail on adjusting the pinion and the bevel gear positions for proper 'tooth' contact.
I have replaced pinion bearings on only 4 vehicles in my life. Each time I did not do any adjustment, but just put it back together with the same shims. And in each case it worked well (and quietly), on a VW beetle, the Ford F1, a Land Rover, and my BMW R69 motorcycle.



From: ClydesdaleKevin
Sent: 7/17/2006 10:35 AM

Another thing to consider is the technical complexity of doing a job like the rearend yourself!  If its just a bearing at the wheels, I'd say go for it, but if its internal, like ring and pinion gears, I wouldn't tackle that job myself for anything!  You have to get the lash JUST right, which means you have to add and remove shims, while constantly checking how the teeth are meshing using a paste on the teeth.  You have to know what you are looking for (the pattern in the paste), and then add and remove shims.  Sounds easy?  You have to have a press to add and remove the shims, since you have to dissassemble and reassemble to whole assembly each time you do this!  And if you are off in your reassembly even just a little?  You will destroy the gears in no time!  As Denison said, rebuilding a rear end is a LOT more complicated and time intensive than rebuilding an engine, and with much tighter tolerances...you can't be off even a little!  On a lighter note, it might not be your rear end...they are almost impossible to kill.  It could be your universal joints, it could be the yoke bearing where your driveshafts come together, and it could even be something simple, like your parking brake shoes at the end of your transmission dragging, or some tiny peice of sheet metal inside that drum at the end of your transmission rubbing on the propellor shaft.  I would explore EVERY other option, including wheel bearings and even your rear brakes/drums, before I tackled the rear axle rebuild!  Good luck!

Kev



From: denisondc
Sent: 7/17/2006 1:43 PM

Well, its not impossible work, but some special tools ARE required I think. The case-spreader would be the first one needed. Otherwise, how would you get the carrier casting out-and-back-in again? Not all axles require this, but the ones on our winnies seem to. I presume you can rent a spreader?
And like I said, I just put the parts back together with the same shims, because I was dealing with bad pinion bearings more than adverse wear per-se. Each of the items I worked on were light enough that I could move them around the floor alone.
I took the pinion gear into a machine shop each time, to have the old bearings pressed off and the new ones pressed on. (You can read the number on some bearings even while they are still on the pinion.)
If anyone does this job, I hope they will give us a description of what it took.
I think I saved a few hundred dollars each time I did it myself.



From: Jupp318
Sent: 7/20/2006 12:21 PM

Many thanks for the reply's, funnily enough a colleague at work suggested UJ problems as have some of you.  It would certainly be easier and cheaper to replace the UJ's first and see where we go from there.

As for the complexity of the job of rebuilding a diff.  I have helped somebody do this before in my Drag Racing days.  The order of the day is patience as anyone who has done this themselves will know.  The frustrating thing is that you can measure everything having put it together once, then knowing what shim adjustments need to be done you take it all to bits swap the shims and put it back together again thinking that should be it.  When you re-check the measurements you find that you've got to do it all again being real careful not to wreck the bearings as you press them on and off.

Having said all that I would prefer not to have to do it at all.  If anyone else has suffered a screeching sound on coast I would like to hear it.

Cheers Ian...



From: jbmhotmail
Sent: 8/31/2006 11:13 PM

Ian, not sure if this will help but check out: Dana 60 Maintenance Manual (3.8 MB) at: http://www.mymopar.com/tools.htm
Be sure to post what cured your problem.



From: Ranse6717
Sent: 9/2/2006 5:28 PM

Ian,
Rebuilding a rear end is a piece of cake............as long as you get your hands on a pinion depth setting gauge and the necessary tools. To be honest, the hardest part of it all is getting the crush collar installed properly. This is a collapsable component that goes over the pinion shaft while you are attaching the yolk. You have to tighten it a little at a time and then check the rotational resistance of the pinion, without the carrier in place, with an inch-lb torque wrench. Tighten, recheck, tighten, recheck, etc. If you over tighten it you have to get a new crush collar and start all over again. Luckily they are cheap. Let me know how you are making out, I may be able to provide further assistance.

Todd



From: Jupp318
Sent: 9/17/2006 1:40 PM

Guys,

Thanks for the replies, I think I will replace the prop UJ's first and see what happens with the noise.  I'm reasonably certain that it will remain as there seems to be excessive backlash as things are at the moment.

Todd,  I would tend to agree with you on the ease of the rebuild with a couple of caveats.  That is the rebuild should be easy enough once the axle has been removed and all the proper tools purchased.  Secondly, someone actually confirms that what we are playing with is a Dana 60.

Cheers Ian...