b7800 locker problems

[captin_insano]

Anyone else have troubles with their diff lock? I bought my b7800 in aug of 07 after doing my research on here to help determine if it was a decent machine. I believe kubota makes a fine product, my dad bought a new b21 around 1992-93 that has never had an issue. Based on my experience with his kubota (approx 1000+ hours of seat time) and help from the online reviews of the 7800 I walked into pristows of johnstown pa on aug 22 2007 and handed them a check for $15,794. Jan of 09 with about 130 hours on the machine and in the worst snow of the year the rear locker quit working. I was without the machine while it was repaired which sucked but I was glad it was repaired without incident. Even though the case was full of metal shavings when they split it I was ok with just the locker repair. Now one year later and with over 30" of snow on the ground and a long drifted driveway I have a B7800 with around 220 hours on it that I cant use because the diff lock has failed again. Last time the case was full of metal shavings so I cant run the thing. This time now I'm having troubles with the warranty. I'm frustrated, I'll detail the warranty issues after the problem is solved. I'm current on my service and dont abuse the machine. I feel I have a lemon and this isnt a common problem but was wanting to hear from everyone if I'm in fact this unlucky? Thanks for listening.

 

[MikeInEburg]

I haven't heard of anyone having this issue on B7800 (or any other Kubota for that matter). I wonder if the mechanism isn't releasing (or engaging) all of the way, leaving it partially engaged when it is not intended. For a second round of nearly identical circumstances, I'd look for a root cause.
Mike

 

[captin_insano]

I hope to get a root cause but unfortunatly after today I get the feeling kubota just wants to say I'm the problem. I know better, I know how the machine was used and am no stranger to equipment so I have found this quite frustrating. I need to vent a little bit of it. The tractor has had a few little issues that I didnt worry about, like a broken hydro line shortly after purchase. I replaced it on my dime and did the 50 hour maintnence. No biggie, I expect that kind of stuff to happen. It began having starting issues too. I had the dealer look at it and they said they adjusted the hydrostat pedal. It worked for maybe a dozen starts, no biggie, when it quit again I simply bypassed the hydrostat safety switch so that I didnt have to deal with it anymore. Then the locker went the first time which bummed me out but was fixed...I guess. Now the locker again and the realization has set in pretty deep that I made a poor purchase with this machine. I do think kubota has quality equipment and suspect this is a rare bad one but so far kubota has really left me less than impressed with their customer service. At first I assumed my tractor was out of warranty since the basic had expired. The warranty rep confirmed to my dealer that the machine was out of warranty, it wouldnt be covered and in fact they would likely not cover it under warranty anyway as they rarely cover locker failures. They "couldnt believe it was covered the first time". I had to call california and the dealer several times and actually read their powertrain warranty to them as written. "36 months" and I read the powertrain definitions as written. So its under warranty but now the best they can do is tear it down and "email pictures" to kubota who will determine if it is a reimbursed claim. Now I'm no metalurgist but I was a machinist prior to my current profession and I dont know how you, for example do a rockwell hardness test on a picture. I feel like I'm being treated like an idiot. I wasnt given any clear answer by kubota customer service as to how it will be determined if the product was defective other than by pictures. I want these answers because I'm not going to accept anything less than a repair paid in full and I refuse to be stuck with a defective tractor and a repair bill. The dealer replied by stating the worst case scenario if warranty was refused and I didnt want to pay for the repair was I'd have to pay the tear down labor and diagnostic time but then I'd have to buy the parts and put it back together. I could be ok with that "risk" but I was just told they cant believe it was covered last time. Theres more yet but I chewed your ears enough for a night. Thanks for letting me vent.

 

[MikeInEburg]

I'm thinking that, short of you driving around with your heel on the pedal, or using at very inappropriate times (use during a turn when on hard surface) you'd have a difficult time causing this issue.
Mike

 

[bstrom]

What are they saying is causing the problem with the diff lock?

 

[captin_insano]

What are they saying is causing the problem with the diff lock

They havent said. last time though the tech working on it showed me the metal shavings in the case and part of the locker and said the new part was "different and probably better". I trust the tech at pristows, he seems to know how to turn a wrench and I didnt even ask what all was replaced.

I think I'd have a difficult time causing it too Mike. Especially since I have 17-18 years on b series kubotas. Over half of my life and by now I should know the machines. I understand very well the bind when turning too, (look at my tinkering post in the build forum). I'm very knowlegable in axles and lockers. As soon as I can get my trailer out of the driveway (enough snow already) its going in for the tear down. I'll personally inspect all the parts and their workings this time and give my opinion. I still think kubota can be a class act, that this is a rare problem and I'll get taken care of. We'll see.

 

[bstrom]

I step on the diff lock after letting off on the HST pedal somewhat and one rear wheel is spinning slowly then it seems to lock in. Sometimes I step on it before I think the wheels might spin without much HST pedal then it goes all the way down just as they spin. Does that sound like correct ways of doing it? Sometimes I feel like I am doing it wrong but I don't know. It sure seems like you would really have to abuse it to grind metal.

 

[manganos]

When I use diff lock I make sure I'm stopped first ....

 

[captin_insano]

The dealer says you need to be stoped but you can find conflicting info on this. Mine hardly ever locks at a stop, like yours I usually have to move/spin a little before it goes in. Good rule of thumb for any locker is never jam it in while one tire is spinning. Although a slow spin (slow being the key) like you do shouldnt hurt a quality component, it makes perfect sense the parts need to move in order to line up and engage. My dads always seemed to go right in, mine on the other hand has never worked like his. Mine you have to put alot of weight on it or it will make like a "skip" and kick out. The more torque to the locker the more it seems to want to kick out. I actually thought about putting an electric actuator on it because you have to push it so hard and mine is mostly used while pushing snow in straight lines. I assumed (or tried to convince myself) it was the way the 7800 was, especially after they fixed it the first time and it functioned the same way.

I've come to 2 conclusions and I'm convinced one of them is correct. Either its a weak inferior locker and I just use mine enough to have the problems (its used alot to push snow). Or conclusion 2, there is some reason its not engaging properly. Once its torn down I'm asking to have the old parts to inspect myself. I'm going to get a rockwell hardness at least just so I know if it's a qulity component from a metallugical standpoint. I may even try to calculate actual torque the locker sees at its wear/stress points when in use and determine based on the strength of the steel just how well they are built.

 

[captin_insano]

My dads kubota is a 92 b2150. Anyone know if these lockers are the same as mine or if they interchange? The rears look real similar, his just works much better. If I have to pay to fix mine I'm going to try to do it once and do it right.