5000 rear axle pinion

Bern

Well-known Member
Location
Mount Vernon, WA
I'm currently rebuilding a 5000 SOS transmission. While it's split and I'm waiting for parts, I decided to clean the rear axle suction
screen and replace the hydraulic filter. While sliding the new filter on, which is located right next to the rear axle pinion adjusting
nuts, I grab a hold of said nuts and to my surprise they are both loose. The lock tab between them is keeping them from backing off,
otherwise they would have walked off long ago. While I can feel no end play in the pinion shaft, there should be pre-load in those pinion
bearings, and those nuts should not be loose.

I've worked on my share of 5000s over the years, and can honestly say that I've never noticed this before. That said, I haven't made it a
point to check those nuts each and every time either. In all my years, I can honestly say that I've never seen one of those rear axles
fail, so that's why I don't make it a point to check them.

My gut feeling is that this will not give a problem, especially for a hobby farmer who puts (I'm guessing) maybe 100 hours/year on it. In
order to check the bearings and/or tighten them, I'll have to remove the RH rear tire, RH axle housing, and diff before I can remove the
pinion assembly. I'm torn as to what to recommend to the owner - I don't want to make a mountain out of a molehill. What would you do?
 
If I was working on it and it belonged to a hobby farmer, I?d tighten them best I could and leave it be.
Besides bern that?ll give you something to do in a couple years when it does fail( kidding).
You could always jack one wheel up and turn the wheel and see if the pinion has any movement it shouldn?t.
 
The problem with your idea, as good as it is, is that it's almost impossible to tighten those nuts where it sits. Unless a person has a really deep socket (like 6" worth of deep), about the best you can do is grab an edge with a cold chisel and smack on it that way. The "real way" to do it is to remove the entire pinion carrier and work on it in a big bench vise. Then there's the issue of not knowing how much preload you've put on the nuts. Too much preload on used bearings is not good either.
 
You could make your own extra deep socket by welding a socket on each end of a piece of pipe.
As for pre load; snug is better than none; but anything is a guess. Not really up to you to
decide; it is what the owner is willing to pay for.
 
I?ve seen some sockets that were made like that for tighten belts on combines. Cut socket in middle and weld pipe in between. It doesn?t take that long to pull final drive and take the carrier out on those tractors.
One thought I had is pinion bearings are usually stuck in place and have to be pulled off. That pinion doesn?t have side load because it?s driven by a shaft that?s straight ( unlike a car that has u joints). Snugging the nuts would probably be fine.
 
After some further thinking on this, along with your feedback, I decided to try and tighten the nuts where it sat (or, as a Ford tractor service manual would say, "in situ"). I straightened the lock tab and removed the nuts, and the front bearing slid right off. The cone, rollers, and cup looked so good you couldn't tell them from new.

As luck would have it, I had access to a 2 1/4" open end wrench. I ran the inner nut on and tightened it as tight as I could with my fingers. I then installed the lock tab and outer nut, getting some good German torque on it ("Goot-n-tight"). I used a vice grips on the pinion shaft, along with a wedge, to keep the pinion from turning.

I marked both nuts before removing them, and checked them after everything was said and done. I got about 30 degrees worth of CW rotation on the inner nut, and about twice that on the our nut.

After locking everything in place, I can easily turn the pinion shaft with two fingers within the backlash zone, achieving what I wanted, which was zero end play and zero pre-load on that shaft.

I'm happy with it, and the customer should be too, as he left it to my discretion as to what to do with it. Thanks for the feedback.
a261631.jpg

a261632.jpg
 
Great to know there was no wear on the bearing from running loose as it was. I don't know that I've ever seen one of those big end wrenches in a 6 pt. I'm surprised you had enough room to get some rotation. Good fix!
 
Most of the turning was actually done with the vice grips, as I had precious little turning angle through that small hole. The reason I dug that wrench up was because the head of my 24" crescent would not fit through the hole. The wrench shown I'm guessing is homemade - there is no stampings on it of any kind.

As for the bearing condition, it did not surprise me. Whatever end play was in that shaft was so slight as to be almost not measurable.
 
Sort of a related question I have to replace the pinion in a piece of logging equipment (long story previous owner trashed the RnP and replaced just the ring gear) that is built from a Ford tractor. From the parts diagrams and your pictures it appears that the pinion housing comes out the front of the rear axle housing after removing the 6 bolts and using the jack screw holes? Would it be possible to get that out without removing the axle trumpet, ring gear and carrier?

I know the R&P should be replaced in set but they are already mismatched and removing the axle trumpet and carrier is a PITA in this machine and right now the owner doesn't want to mess with the ring gear if we don't have to.
 
If it's like a 5000, the diff has to come out before you can remove the pinion. There is a bearing behind the pinion that will not clear the
ring gear if you try and pull it straight out.
 

When I have found myself in that sort of situation I would usually get ahold of the owner and describe the situation, give him the estimated cost along with my recommendation and let him make the choice. I found that it almost always made the customer feel very good to be consulted.
 
It is built out of a 545 industrial I think, which looks nearly the same as my 5000. Assuming the bearing is pressed onto the pinion so little chance that it will stay in the axle housing?

How far does the ring need to slide back for the bearing to clear? Possible to just put some studs in the axle trumpet and slide it back an inch or two without removing it and pushing the differential carrier back?
 
The rear pinion bearing is retained by a snap ring, #55 in the pic below. So pulling the pinion out without disturbing the diff is not going
to happen.

I can't tell you exactly how far you'd have to pull the diff to get the bearing to clear, but I would think 2" would get the job done.
Snap ring 55
 
(quoted from post at 10:23:11 03/18/18) The rear pinion bearing is retained by a snap ring, #55 in the pic below. So pulling the pinion out without disturbing the diff is not going
to happen.

I can't tell you exactly how far you'd have to pull the diff to get the bearing to clear, but I would think 2" would get the job done.
Snap ring 55

OK thanks. There is enough room to slide the right side trumpet out a few inches without dismantling the entire frame of the machine. A few studs in place so the trumpet and differential can slide out without having to remove it should work.
 

In the automotive world...

New 12 to 18" pounds
Used 8" lbs

I have always said you can not install the carrier bearings to tight there is a spec on it tho a often un-listed spec.

Assemble the pinion and pre-load
install the carrier
check Turing torque at the pinion.

Multiply the torque by 3 times the diameter of the ring gear and add the pinion torque.

Let say the diff ring gear is 12", 3X12 = 36 plus 18 = a max of 50" lbs on a assembled unit...

On a tractor like yours run the nut up take the slack out and just bump the nut to set it then set the jam lock nut tight and move on with life... When you set the jam nut it does add to the preload not much but does affect preload....
 
Personally, I think I'd check them... My luck always seems to be that if I ignore something like that it will BITE me, sooner than later. If it's an open station without a roll bar... that's 2-3 hours? Mabey? I do tend to agree with you that nothing is likely to happen if you don't... but sometimes peace of mind is worth something.

Rod
 

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