Hyd Pump Drive Shaft Seal

[JohnL (BlackJeep)]

Hi all,

I'm in the process of re-assembling my hyd pump (355005-R93) with a Case IH gasket set (355208R91) and I couldn't get the drive shaft back through the o-ring seal without damaging the o-ring. The drive shaft has a very sharp "step" in it, and it is such a tight fit through the o-ring and front case that it basically sliced off a piece of the o-ring.

Before I buy another o-ring, is there some trick to this that I need to know? Could it be the wrong o-ring? It fit in the hole OK, but man was it tight around the drive shaft.

As always, thanks in advance for your expertise.

BlackJeep

[John *.?-!.* cub owner]

You might chanfer the sharp edge a little, and be sure to lubricate the oring with Hytran. if you used a universla oring rather than Ih replacement you may have one that is too thick.

[JohnL (BlackJeep)]

John, thanks for the quick reply.

I thought about giving it 30 seconds in the lathe before I started, but I thought there must be a better way.

I just chamfered the shaft slightly as you suggested, now it goes in without hacking up the o-ring.

Too bad I trashed the correct o-ring first!

Chalk this one up as another learning experience. I think I'm gonna need more chalk...

BlackJeep

[Don McCombs]

BlackJeep,

How did you chamfer the edge? With a small, fine file?

[JohnL (BlackJeep)]

Don,

I put it in my lathe with the threaded end in the chuck (I left the nut on the shaft and used the nut to drive it) and used a live center on the other end of the shaft. Then I used a regular carbide cutting tool angled at about 45 degrees to make the chamfer.

It's not a very big chamfer, maybe 1/16" or less.

It worked well. Now I just have to order another o-ring to put it together permanently.

BlackJeep

[Dennis B]

Another trick is to put the o ring on a wood dowel with the OD a little larger than the shaft the o ring will be going on. Use a small piece with the one end cut off square and the other end rounded. Lube everything good with the lubricant that is used in the part your redoing. Butt the square end against the shaft and simply slide it off onto the smaller diameter shaft. I usually sandpaper the edge of the shaft in case of any nicks or burrs but this is a simple solution without trying to roll it onto a sharp shaft. It works for me!

[John *.?-!.* cub owner]

Tha wrks good on many shafts, but the hydraulic pump has a threaded end a little smaller than the shaft. might be able to wokr by drilling the wooden shaft, but a pretty cloe fit to do it.

[Dennis B]

To get a o ring over threads I have taken fish line or for larger threads have used string and wrap the line or string in the grooves of the threads. Holding the line in place finish by wrapping it smooth with electrical tape. The purpose of the line is to fill in the grooves. Then simply lube it up and slide it on.