3165 Diff Lock

Hi All,
I bought a 3165 loader a few years ago.(I think it's an "industrial" version of a 165).
It had sat a long while & the clutch was rusty & bonded up.
I fixed it up & it runs well.

However,the diff lock ,located on the right side of seat,is not operating.It feels frozen.
I can stand on that pedal,but get no movement at all.
I took the pedal mechanism off & tried to move/turn the actuating shaft....but no luck.

Would this system be rusted/frozen up....or is there another issue here,that required total dismantling?
Luckily,I have the manuals.

Your help is appreciated.

Jim

The rod moves to the right to mesh the jaw type diff lock, and it looks to be really rusty. If you can free up that rod it will work again. If it moves at all jack up one rear wheel to help align the jaws so the rod can fully travel. There's a heavy spring inside to move it off also when it does move.

(quoted from post at 18:27:28 11/08/16) The rod moves to the right to mesh the jaw type diff lock, and it looks to be really rusty. If you can free up that rod it will work again. If it moves at all jack up one rear wheel to help align the jaws so the rod can fully travel. There's a heavy spring inside to move it off also when it does move.

Click to expand...

Thanks DieselTech,
I will try & clean that shaft as good as I can.
Just wondering if it's worth heating it up (a little) ...maybe get it to contract/expand a bit.Or are there seals in there that will melt?

I drove it forward yesterday & tried levering the shaft at same time,but no movement at all...

Thanks again.
Jim

I had the exact same problem with my MF 165. I needed to replace the brakes on mine and decided to fix this problem as well while I had the
axle housing off the tracto.

The shaft was frozen solid and no combination of penetrating oil, heat and pulling the shaft using a slide hammer from the gear side would get it
to budge. I tried pushing the shaft by wedging a block between the housing and pin an pushing the shaft with a pry bar. If you try this, be
certain to fill the gap in the shaft because mine ended up breaking at this weak point.

What I ended up having to do was this.

1. Remove the axle housing from the tractor.
2. Using a 1/4" punch, drift the pin out of the differential arm (this enables you to separate the outer housing and expose the brake assembly)
3. Remove the outer cover to expose the brakes. Remove the brake disks, brake actuator assembly and axle shaft.
4. From here, you should have a full view of both sides of the differential lock shaft, spring and spring retainers. Your goal should be to break
the diff lock shaft free without damaging it. Soak the contact points of the shaft with penetrating oil and let it sit for a while.
5. To break the shaft free, use a torch to heat the areas of the housing where the shaft passes through, place a wooden block on the end of the
shaft and hit it with a mallet. The wood block is to prevent damaging the end of the shaft. I was able to drive the shaft in very slightly but it
would not free up. Note: you can only push the shaft into the housing a bit. There is a snap ring on the shaft that secures the left spring
retainer that will prevent the shaft to moving far.
6. I then tried to use a slide hammer to pull the shaft. I inserted my 1/4" punch into the pin hole on the end of the shaft to act as a blocker and
clamped vice grips on the shaft just behind it. I then used a 2-jaw clamp on the slide hammer (available for free use from most hardware
stores) attached to the vice grip body and tried to pull the shaft to break it free.

For me, none of these approaches would free the shaft and I realized I wanted to remove it I would have to cut it out. I used a reciprocating
saw with a Diablo carbide blade ($14 at Home Depot). Don't try bimetallic blades as they will quickly dull. The Diablo is hands down the best
way to go. If you were unable to get the shaft to move at all previously, you will want to use the mallet directly on the end of the shaft. Your
goal is to get any movement at all before moving into the next steps.
7. I cut the left side of the shaft off right at the housing to create plenty of room to drift the frozen section out later.
8. I then cut the middle part of the shaft right through the spring. Do not damage the spring retaining caps when doing this.
9. With the shaft now cut in the middle, use penetrating oil and heat to prep and go back to step 6 using the slide hammer to remove the right
side of the pin. It may take some coaxing but it should eventually pull out.
10. Remove the spring and end caps. Also, remove the snap ring from the shaft.
11. Using a steel rod (I used a 10" 5/8 lag bolt) and mallet, drive the remaining pin section form the end of the housing until it falls out.

Using this approach, you will need to replace the shaft (about $90) and spring ($17).

I hope this helps.

Bryan

If you do end up needing a new spring, let me know. I ordered 3 to meet the suppliers minimum order amount and have two left. I'd be happy to send you one at cost.

Bryan,
Thanks for the detailed reply.
I think my unit is the same as yours...very stuck.
I tried levering & even a pipe wrench,but I'm getting no movement at all.

This is typical of a tractor that has sat in the elements for too long.After getting the clutch unstuck & repaired,I found the tractor is going well,& has been handy. I think I'll need the diff lock when trying to fill the bucket or towing,so I'll follow your advice.



Thanks
Jim