Cub Cadet/Yanmar SX3100 slipping out of 4WD unexpectantly

gaheadrick · Mar 30, 2014

Yes, definitely. Yanmar and my dealer have been outstanding in their efforts to rectify the problem and provide an immediate solution for me. The SX 3100 is an excellent machine, a great size CUT, and in all other respects as it always performed well and I will miss it. I'm confident that Yanmar will be doing their most professional assessment when they get the tractor back to Atlanta to find the source of the problem and will hopefully issue an official fix or set of fixes.

As for what to buy next that is yet to be determined as I do want to a different machine to potentially have the same issue on the significant slope. It may be a challenge to any 4WD mechanism or maybe not. I would definitely appreciate any helpful insight as to what I should be considering. So far at least I'm considering a heavier machine with a longer wheel base to help balance out weight to offset some of the pressure on the 4WD detent. I've been all over the board...Kubota 3350SHD the lightest of the group, Mahindra 3616 HST, New Holland Boomer 35 HST, Massey 1736 HST, Kioti CK35HST and even a JD 3039R HST. One suggestion that has been made is to buy a geared machine rather than an HST with the idea that it would create more geared resistance downhill or at least use a three range HST. That may be helpful or it prove not as the issue is the connecting mechanism of the 4WD that really counts in this situation. Any advice appreciated.

snohobigdad · Mar 30, 2014

I admit to liking green so I know my thoughts and research are biased in that direction. What you choose is dependent on what kind of work you want to do. If heavier is a must, I have NOT heard any issues with the 3 series Deere's relative to the 4wd popping out. Hydro or otherwise. A word of caution on the Deere is if you want a mid-mount mower (ever) you need to choose the right 3 series. Moreover, even if you choose the right 3 series, make sure it already has a mid-PTO as it is costly to go back and add it in. This may also play for a front snow blower configuration too. I am not sure on that one as I never had a need and consequently it was not part of my research criteria.

No matter what, please keep all of us abreast of the findings by Yanmar as there quite a few people who would like thief machines to work as designed and intended. And that is way more than me!!

Best if luck with your research and choices. And I bet you are looking forward to saddling up again. Jim

BB4U · Apr 23, 2014

I had the same problem when going downhill. It made for a "hold on and ride it out" experiences. It turned out that Yanmar was aware that the problem occurred in some of
their tractors and had a fix for it. The local dealer installed a heavier dent spring in the shift fork mechanism. It did need to be split and torn down to install the heavier spring.
Yanmar footed the bill under warranty. I will find out this growing season if the heavier spring does the trick.

snohobigdad · Apr 23, 2014

BB4U

Deere is in denial. And since many if us are beyond warranty they thumb their noses at us. In my mind, this is not a warranty issue. It is a design flaw. I work for a very large engineering firm. This is not a wear issue. Too many of us are running into this with little hours on our machines. Provided the heavier spring is the repair, some engineer who designed the mechanism miscalculated the loads placed on the spring and selected a spring that was too light.

It is all about the math. Good math will yield a good design.

gaheadrick · Apr 24, 2014

As a follow up to the Yanmar SX3100 slipping out of 4 WD I can say that Yanmar and the dealer recognized this as a serious safety issue. They did their best to fix the problem twice by replacing the spring with the dual spring/a spring within a spring. And this did make a significant improvement...to the point where the machine would not slip out of 4WD if unloaded. As I had continued to use the tractor and as I added load it slipped out of gear again which was communicated to the dealer and Yanmar. They were upfront and outstanding in their actions to buy the machine reimbursing me for all my costs. They have shipped the tractor to Atlanta and are likely in the process of disassembling and reviewing the transmission in detail. They want to resolve this issue.

I agree with this being all about good math and design. Based upon my experience, and in my personal opinion there was a design flaw with the original "single" spring as one part of the issue. Yet, also in my personal opinion, there is something more, like the button or bar, which guides, retains or positions the 4WD mechanism. If this is out of tolerance, worn or out of position the 4WD mechanism is in all likelyhood compromised. It is only my hunch, based upon my experience and others' reports regarding replacing this button/bar, that this is potentially the second part of the fix. I'm confident that the Yanmar engineers will determine exactly what needs to be done to finally solve this problem. It is unlikely that they will advise me directly of their findings but if I learn through my dealer I will advise everyone here. Meanwhile, I suggest remaining in communication with your JD and Yanmar dealers and service people for any breakthrough news about it.

Meanwhile, after having completed some exhaustive research on replacing the tractor I've decided on a Massey Ferguson 1736 HST, their latest design, which does have a mid PTO and the capability for mid mount mowers, front snow blower, etc. It is a more costly replacement option... bigger, heavier machine with 3-range HST and has the new Mitsubishi Tier 4 compliant diesel engine. I also looked very hard at the Mahindra 3616 but it did not have the side by side dual HST pedals which I had grown comfortable with. Also, the JD 3039 tractor is a great new machine and has everything the Massey 1736 does but the price was several thousand more dollars. My new tractor should be in sometime this week and when I get it here on site the first thing I will do is grab a load and head down hill...cautiously, hopefully, expectantly and we'll see if the 4WD holds its gear! Yes, I'm very much looking forward to getting back in the saddle! My best wishes to all who are awaiting on the Yanmar solution.

snohobigdad · Apr 24, 2014

Thanks gaheadrick.

I am using my JD2305 on the hills at the house so I am safe and good. Still a 62" MMM, and in some ways more comfortable.

The JD2720 will stay at the farm which is virtually flat it can handle a bigger brush hog. Oh well

gaheadrick · Apr 24, 2014

Hello Snohobigdad,

It must be nice to have both of your machines to pick and choose for the job at hand! Both are very good machines and hopefully there will be some positive news for the 2720 regarding enhancing the 4WD in the near future. Your plan for time being sounds solid and safe.

snohobigdad · Apr 24, 2014

Thanks GA! One was planned, the other in response to the farm which came when I got married last year. I also got a really cool tool too.

gaheadrick · Apr 25, 2014

Wow...that's a classic tractor and very cool!. Thanks for posting the photo. Also belated congratulations on your marriages, the one to your wife and now the farm...way cool!