Hanson Hydraulics Ltd. Blog

Waratah Poclain motor reseal MS08

Posted by Doug Hanson - 11/11/09 at 04:11 pm

To perform a fast shaft seal replacement on a Poclain MS08/Waratah motor:

Hanson Hydraulics Ltd. Blog article:

A quick reseal on a Poclain MS08-9-12A-A08-1129-DJMO motor. This unit is off of a 622B Waratah processor head. A factory seal kit is around $900.00. In this instance the customer wanted just the shaft seal replaced with absolute minimum down-time.

Ordering the high pressure double lipped shaft seal and housing orings came to $30.00. The following description of work covers only a fast shaft seal replacement. This is not a complete rebuild.

First, note direction of feed wheel. To change the direction, the wheel flips over, allowing the motor and wheel assembly to be used on the other arm. Remove the wheel.

Remove the housing bolts, remove the port end cover, be careful as the distributor may drop out of the cover, usually they stay sitting on the cylinder block, but be careful not to drop it, there are springs that load the distributor up against the cylinder block.

Remove the cam ring and the cylinder block. Remove the snap ring on the shaft, followed by the shims.  It is sometimes necessary to press on the inner bearing race to take the tension of the snap ring in order to get it off.

Support the housing, make sure there is clearance below for the output flange, and press the shaft out.

The outboard cone will remain on the shaft and is not removable without possibley destroying.  This bearing runs outboard of the shaft seal, so it does not get oil. Repack this bearing as is using a grease gun with needle attachment. There is a grease/dust seal between the outboard cone and output flange.  This will not be changed as it would necessitate removal and possible damage to the bearing.

The seal carrier is removed from the housing by driving out towards the cylinder block.  It will not pass through the inboard outer race, so this race will be driven out as well.  Find a driving tool with the largest diameter possible so the seal carrier does not become distorted. Drive or press the assembly out.  There are two seal carriers, the outboard has the double lip shaft seal, and the other has a high pressure PTFE seal.  In this instance the PTFE seal was not changed.

Pay attention to the stepped face on the high pressure seal carrier and make sure it is installed in the same direction.

Replace the double lip seal, applying a film of Ultra Blue to the outside of the seal. Make sure the housing and seal carriers OD are oil free, and apply a film of anaerobic sealant to the outside of the seal carriers.  Press back into the housing, but take as much time as you need to not distort the seal carriers! Be careful!!!. Press the inboard cup into the housing.

Put a film of grease on the lips of the seal, add a bit of grease to the cavity for the outboard bearing, and install the housing over the shaft.  Heat the inboard cone up and install it onto the shaft, followed by the shims and snap ring.

Reinstall the cylinder block, housing oring, cam ring, and install oring into the port end cover.  Clean the distributor and spring, making sure they are free of oil and grease the springs so they will stay stuck in the distributor.

Install the distributor into the port end cover.  Take a small piece of plastic round stock and insert it through one of the ports so that it will hold the distributor in place.  Tension will need to be maintained on the rod or the distributor will drop out, do not let the distributor drop out!!!

While maintaining tension, install the port end cover on top of the motor assembly, tighten the bolts up, If it appears there is any interference among the parts, investigate!!!.

Inner cup and cone A&S 31313F

Outer cup and cone A&S 33214F

Shaft seal BABSL 070090070-1  (70mmx90mmx7mm)

2-178/N1470 oring x2

 * Some units may use a 70mmx110mmx8mm shaft seal

Written for Hanson Hydraulics Ltd. Blog

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This entry was posted on Wednesday, November 11th, 2009 at 4:22 pm PST and is filed under Pump and Motor Repair. The entry is tagged under You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.