# Steiner S20 hydraulic coupling problem



## TimTur (Sep 25, 2012)

Hello: I have a Steiner S20 1980's 4 wheel drive, hydraulic dump, articulating mower with 20 HP Onan with the hydraulic pump mounted to it with a QM Bearing coupler with a blue rubber insert. I've owned this tractor for over 20 years and love it. I've changed the coupling a few times over the years. This year I've changed it 3 times, twice in the last couple of weeks after an hour of cutting. I've changed the hydraulic filter, and cleaned the engine fins because I thought it was getting hot and melting the coupling. The coupling can't be out of alignment because the pump is mounted with a cast bracket directly on the motor. It seems like it's going out after getting hot. I do use it on hills. Is there maybe a relief valve in the pump that isn't working and putting excessive strain on the coupling? Looking for any suggestions. I don't have any repair manuals for this tractor. Thanks and hope someone can give me a direction to go. I love this tractor.


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## 2jdeeres (Apr 14, 2010)

Check the bearing , if one is starting to go out it can generate a lot of heat and transmit it to the coupling.


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## TimTur (Sep 25, 2012)

*hydraulic motor coupling giving out response*

Hi 2jdeeres:

This is a coupling, not a bearing. The product is sold by a bearing company. I've attached two pictures, one is what the coupling looks like from company brochure, the other is a picture of where the coupling is located. On the left of the picture is the hydraulic pump, in the center under the bracket is the coupling, and on the right is the shaft of the motor. There is an solid aluminum bracket that attaches the pump to the motor, and the coupling attaches the two shafts. The rubber spider part of the coupling is giving out and melts from heat or torque. The tractor works fine until the coupling gives out. No hydraulic issues seen or heard when in operation. Sorry picture of tractor coupling is flipped, pump is on right side, engine on left.


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## 2jdeeres (Apr 14, 2010)

I meant what the coupling hooks to, if that shaft bearing is going out it can transmit a lot of heat to your flexible coupler.


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## TimTur (Sep 25, 2012)

So what your saying is check either the motor shaft bearing or the hydraulic pump shaft bearing? I'll separate the coupling and check to see if there is any play on either side. Thank You. I'll let you know what I find.


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