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Small Engines (Lawn Mowers, etc.)/Hyrdostatic transmission proble John Deere 345 mower


Carl Halgren wrote at 2009-09-04 21:06:51
I have had essentially the same symptoms, twice. I just discovered that my problem involves the brake not fully releasing, as it should to allow normal movement both forward and reverse. The quick "solution" is to physically pull the brake pedal back so that it fully releases the red plastic parking brake." The transmission growling immediately disappears and the tractor moves forward and backward as it should.  Each time I use the brake the problem returns, but pulling the brake fully off immediately "fixes" the problem.

When I take off the mower deck this fall I should gain the clearance I need to check whether the linkage is properly turning a part on top of the transmission or whether some other part of the linkage isn't working properly.

Last summer the local John Deere dealership took the transmission apart, found nothing wrong internally but returned the tractor "fixed", probably having lubricated the linkage, with a large bill for the effort.  All the symptoms mentioned returned again this July.

I hope this helps.

Don wrote at 2011-07-25 23:45:02
My 345 growls a little when trying to go forward when cold, after 20 feet or so it works great and reverse works also, let it sit for a hour ... same thing all over again, If any one has found out what is going on PLEASE REPLY,  

ATD wrote at 2012-05-30 22:06:59
This unit has a hydrostatic transmission.  The forward/reverse pedals rotate an input shaft linkage that rotates a swath plate in the hydrostatic axial piston pump.  depending on how much angular turn it gets from the 12:00 position CW or CCW determines the pump flow and direction, and also ground speed.  If you disconnected everything up to the transmission and the lever moves freely, then you've got something binding in the pedal linkages which is easy to inspect and fix.  If the swath plate shaft itself binds, then you have an issue that likely needs dealership attention.

The initial symptom is consistent with inability to build hydrostatic charge pressure, most typically caused by a clogged filter in the tranny.  If the power steering or lift also seem to operate erratically or with low power, this would confirm the filter problem.  If it's not the filter, you could have a worn charge pump or a failed leaking internal hydrostatic components.

I assume when you were talking about fluid level, you meant hydrostatic transmission fluid level measured at the back of the tractor and not engine oil???  Low oil level would not cause engine overheating.  1/4 qt down is not an issue, the hydraulics also use this fluid reservoir so depending where the steering wheels are turned and the lift position this will change the fluid level.  

But yes, before you go ripping transmissions apart, the first thing to do is drain the fluid (as per the OM) and replace the main filter as well as the in-line hydraulic filter.  Then refill.  If the problem persists, look carefully at the oil you drained and at the main filter you removed.  Is there metal shavings settled in the oil?  Sometimes it helps to drain the oil through a coffee filter to better see if there is metal in the oil.  If yes, then something has failed in the tranny.  If it looks clean, then you need to look at pressure testing the charge pressure loop (steering) and FR check/relief valves.  This is something you can do, but a dealer is better equipped.  After changing filters, the next thing I always advise is to replace the FR check/relief valves as well as the charge pressure regualtor/relief valve.  They are cheap and can cause serious issues if they get finiky.

That's my 2cents

Thunder wrote at 2016-05-01 18:51:54
Check the bushings where the brake pedal shaft goes through the frame. There is a steel bushing for this shaft on each frame rail. Since they are both made of steel they can eventually rust and start seizing on the shaft. The frame bushing on the RH side (as you face forward) will most likely be the culprit. They are not very expensive but can be difficult to replace depending on how badly seized the bushing might be. A good indicator of this problem is if the brake pedal will not return to its normal rest position and has to be pulled back with the foot or hand. The return spring for the brake pedal is quite strong so if the pedal doesn't return freely this could very easily be the problem. It should also be noted that the transmission release rod cannot be pulled into the release position to push the tractor unless the brake is in a completely released position.  

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Howard Buchin


How can I fix my small engine problem? Is a good question I can respond to. This includes how to overhaul engines, carburetors, valves, pistons & proper diagnostic testing. Questions regarding the worth of fixing a machine or buying a new one, I can adequately respond to. Questions that I'd have difficulty with, include: how can I fix a sm. engine transmission problem, some electrical type problems, and/or any models that I am unfamiliar with.


I have experience repairing lawnmowers [manual self-propelled], weed-wackers, chainsaws[electric and gas], leaf blowers, blade-sharpening, snow-blowers. My experience includes repairs to Briggs & Stratton, Lawnboy, Toro, Stihl machinery.

I have had some of my written work published in local newspapers.

I've completed a small engine certificate. As well, I've completed Automotive Engines 1, & Basic Brakes & ABS Theory, at Centennial College. I also have credits in Computer Hardware Repair & well as five credits in Paralegal training.

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I owned and operated Buchnor Home Services, with commercial and residential clients in and around the G.T.A.[Greater Toronto Area].

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