I'll preface this with I haven't yet picked up the dozer (350C), but will be hopefully this or next weekend. The machine has a sheared coupler and/or transmission shaft. The current owner has done this once before and went in through the engine side to replace the coupler. When doing some net surfing to look into the problem I found more than a few images of sheared splines on the transmission. I'm guessing this is predominantly from abuse, but looking at it I wonder if a pto slip clutch possibly would save such a disaster? http://www.tractorsupply.com/webapp...ory_rn=&top_category=&urlLangId=&cm_vc=-10005 The torque to cause such a shear, the engine is not capable of producing, so I imagine high gear runs at stumps or other such abuse, but a single goof engaging a gear and hitting an obstacle seems like it could accidentally produce the same results...(?) So since I am going to have to pull the tracks, finals, main, and possibly the reverser and do full transmission tear-down(s) to replace the shaft(s), I can't help but think about cutting the spline sleeve coupler, and machining slip clutch ends to accept the ends. I couldn't find a net image of the reverser splines and main input splines to try and figure out how close they are, but about 1" end gap would be needed to accommodate the pilot bushing in the slip clutch. Otherwise modifying an off-the shelf clutch looks to be relatively simple. My thinking is NOT to allow the machine to be abused, but to save costly damage from a potential single goofup. Thoughts? Good idea? Bad idea? PS here's a pic, the machine is in *otherwise* decent shape.
You have a nice looking machine there. We have a 350 B at the camp not as nice as yours, but very useful. Hope we don't have to dig that deep into ours. A few years ago rebuilt steering, brakes, engine overhaul and rebuilt blade pivots. It did earn its keep by doing a few part time jobs. Good luck with yours.
Where the frame bolts to the final drives those dozers are prone to breakage. When broke/ loose at that joint they will tear up that shaft in no time.
Oh wow, thanks for the heads up. I will take special care on the way in to straighten it out if this is the problem.
Quote from jdemaris on "yesterday's tractors" http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=crawlers&th=65786%3E We had to fix many 350 transmissions. They do not shift well on the fly if equipped with a hydraulic reverser. That because they use sliding-gear transmission - not constant mesh collar shift. So, after years of shifting while moving and clashing gears - they get worn down to a point where they will no longer stay in gear. We took a few and, with a grinder, reshaped the remaining gear stubs so they could be used a little more. If you plan on swapping cases - be very careful about the dowels and holes where the trans. case bolts to the reverser. They tend to get egg shaped after years of being run loose - and when that happens - the trans and reverser get out of line and the splines get ruined on the shafts where the coupler goes. The side-frames also crack. If you have a case with worn dowel holes - fix it or don't use it. Otherwise you are in for a mess. I suspect the main culprit is the bottom two bolts that hold the reverser to the trans. case. They are near impossible to tighten properly. We were told by Deere engineers - that at the factory - the bolts got tightened with the trans and reverser out of the frame. So, with a complete and assembled machine - they're not very accessible. We used special short box-wrenches with a chain hooked to the end. Even with that, we had trouble getting them tight. And - to take the bolts out for the first time with a new machine - again - pretty difficult. We got so, with new machines - we heated them red hot until they stretched and got ruined. They'd then come out easy. I mention all this - because it seems the cause of the many bad transmission and reverser cases in 350s is caused by those two bolts never getting tightened properly. Maybe someone out there has come up with a better way to do it? In our shop - we tried just about everything - and Deere engineers had no good answers (they rarely did). Thus, the short chain-wrench. I'm posting this up as info for anyone else who goes down this path. Unrelated but I'll add that roll shifting a sliding gear transmission varies a bit. Big rig sliding gears are designed to allow roll shifting, but sliding gear type tractor transmissions are more like automotive sliding reverse gears- NOT meant to and very intolerant of roll shift. A dozer with a reverser is much worse since the inertia of the reverser guts adds to the destructive force applied to the engagement tapers on the teeth.