Changing grass height when using self-propel

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I have a 21" self-propelled mower although I don't use the SP feature too much to save battery time. This spring as I was mowing a slightly sloping lawn I used SP when going uphill and pushed when going downhill. I quickly noticed that the grass heights were quite different - much higher when using SP. With manual use the grass height certainly wasn't the 3.5" it should have been. Finally I noticed that the whole mower would lift when I engaged the SP lever resulting in the higher grass. Is this normal?
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Thomas Trischmann

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Posted 1 year ago

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Blue Angel, Champion

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Others have reported this issue.  It seems to occur with a combination of grass height setting and incline slope.  The torque from the drive motor seems to take up some slack in the height adjustment mechanism, but this only seems to happen when going up a slope and/or when the height adjustment is set to higher settings.

Cutting on level ground seems to be OK from what I can tell.  I don't own the SP mower, mine is the older 20" model, so I can only comment based on what others have reported.  There have only been a few reports of this happening.

Does the issue persist if you push the mower slightly while propelling it uphill?  I'm wondering if taking a bit of the load off the SP motor would allow the height mechanism to relax?
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Pete Innes

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We had a mower that stripped the gears on the rear wheels. We used it as a push mower. It cut lower on level ground. If you have the self propel, you need to use it at all times to maintain a level cut. The torque of the motor lifts the deck slightly
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Thomas Trischmann

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Thanks for the feedback. I am using height adjustment 5. I can try suggestions when it stops raining! The grass height is actually better when using in self-propel mode so I could just be lazy and use it full time if necessary. The down side is not being able to do both the front and back yards on one charge but the recharge time is quick. Or maybe things will settle down when the spring growth surge is over.
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Blue Angel, Champion

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The Lawn Care Nut did a great two part review of the SP mower. He has some great feedback and helpful tips for getting the best out of the mower:

You might find some useful tips in there. He compared it to some high end gas mowers and gives it some decent praise.
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I have the same problem.  It is amazing how much a difference the self-propel makes.
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Ken, Champion

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I recently picked up the self-propelled mower and haven't experienced this at all.

My mower has a January manufacture date and apparently has an updated self-propel drive that's shared with the steel deck mower.

I wonder whether this refinement to the drive system addresses this problem?
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Dave Lundy

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it totally does in my experience having had both versions.
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Thomas Trischmann

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Has anyone with the changing height problem sent the mower for a warranty repair? I was going to but found out at the Home Depot that it takes 6 to 8 weeks to get it back. I'll try over the winter but was wondering if the repair works.