Follow-up to sticky hydro. pedals

Mark_in_NH · Feb 16, 2004

( what are you waiting for !!!!! )

Hmm !! Ultimatly a 40' x 60' heated shop, but if I wait for that I would never get any tractr maintenance done. So, I will settle for some temps in the high 30's /forums/images/graemlins/cool.gif

jinman · Feb 16, 2004

Mark, I can't guarantee you won't mutter a few choice words, but I'm attaching a photo with a highlighted oval showing where you need to lube. It's the roller on the end of the tension bar shown as item no.26 in the illustration in my previous post. This roller runs on the edge of the "B" shape and the spring tension tends to make the "B"-plate rotate back to center from either the forward or reverser positions. You can see the shaft entering into the hydro tranny by passing through a hole in the running gear. The operation of the pedals is completely independent of the hydro transmission.

In my photo, I had the operator's platform raised about 16", so you won't see it this well when you look up from the bottom. You should be able to work the pedals and see exactly where to lube. It makes a big difference in my tractor.

Good luck and stay warm! /forums/images/graemlins/grin.gif

David2 · Feb 16, 2004

In a perverse sort of way, I am kind of glad to know that this is a common problem, in that I don't own a lemon that I am stuck with. I knew my dealer would not be able to do anything about a non-specific problem like this and I was not looking forward to waging a un-winnable debate with him.
I think my next step is to inform NH in a way that perhaps will at least make them ponder the possible liability issuses that could surface. While I greatly appreciate the detailed instruction and advice from all of you, it really should be coming from NH. I do not believe they are ignorant of this particular problem. I had already planned to appeal to NH about the damaged lift arm caused by hydro/defective material problems. I now am going to print and enclose a copy of these posts along with my communication. Cannot see where it will do any harm, and they will also not be able to plead ignorance. We all gave them a boatload of cash for their equipment and they should at least try to assist and/or correct what they can.
Regards,
David

tc35dforme · Feb 17, 2004

Jinman, since you're much more mechanically inclined than I....and since I had no idea that there was a damper on the pedals until you pointed it out, would I be off in the thinking that that damper is more the issue here ? Is the damper a shock absorber type arrangement ?? Did you have the pleasure of removing it during your rebuild ??

Maybe for us cold weather guys, the fluid in that damper is more likely to be cold and thick and unable to slosh through the ports. Is it more a function of cycling the pedals ( to warm that fluid by friction ) and less a function of the hydro fluid in the transmission ??

But then again, how would tis ingegrate with the 'under load ' issue ?? Hmmm

I'd be curious to see a new DA up close to see if they've changed the pedal geometry or fit-up.

KrisHansen · Feb 17, 2004

(
Do you Class II owners have the same problem ?? )

I do not have this problem at all.. Even when it's below 0f, my pedal returns to 'neutral' on it's own. The only time I sometimes have to help it by pressing on the reverse side is when I am going down my steep hill at full forward.

jinman · Feb 17, 2004

Before I make a foolish statement and "paint myself into a corner," let me say that I have not tried what I am going to suggest, nor do I really even know if it is possible. /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

Having fully disclaimed this procedure, here is what I think:
If you want to eliminate the damper as the possible problem, it can be disconnected. Look at the 1st photo of my "B"-plate above and you can see a pin with a bent cotter key sticking out of it (just behind the broken bracket I'm displaying). The return damper attaches to that pin. If you get under your tractor and remove the return damper, it should allow you to experiment with what it's effect is. If there is no significant change, then it's probably not the problem.

I don't know for sure how close this area is to work since I haven't looked at it in awhile. You surely want to make sure nothing is going to get hung up while testing and sending you off on a runaway tractor. After the end of the damper is disconnected, you might even temporarily be able to tie it back out of the way long enough to do the test.

Let me end as I started. I have not done this and I'd caution anyone who does to be extremely careful. /forums/images/graemlins/crazy.gif

tc35dforme · Feb 17, 2004

Jim...are you recommending that we disconnect..... /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

I may play with that when it warms up a bit.

I'll update with any news.

DVerbarg · Feb 17, 2004

Just read this thread and like Jim said, you don't want to have the experience of becoming intimately familiar with the "B" plate - it becomes a memory you will never forget. /forums/images/graemlins/crazy.gif

This return damper idea has me wondering if mine works well. I do remember disconnecting it and reconnecting it (along with hundreds of other fasteners) but in experience I know that if I turn off the cruise the tractor comes to a screaching halt as the drivetrain immediately stops. If it weren't for the seat belt I would have been launched quite a few times from my seat.

I don't have much problem, anymore, with the hydro pedal not wanting to return to neutral when under heavy load. When I first had the tractor I usually ran the engine at lower RPMs and tried to use the pedal like an accelerator. Since then I have gotten a little bit wiser and now usually run the engine at much higher RPMs thus avoiding much of the problem of "lugging" and the associated hesitant pedal. In those rare cases when the engine begins to "lug" I instinctively let off the pedal now knowing that keeping the pedal down is like up-shifting in a manual gear transmission when under load, it does not make sense.

Of course the lubrication that Jim mentioned makes a world of difference. Just one quick note, try not to get excess lubricant on the broad transmission side of the "B" plate. This is the side that the cruise control electro-magnet adheres to when the cruise control is activated. If lubricated too well your cruise might tend to slip. Don't ask how I know ... /forums/images/graemlins/blush.gif

Yes, I think NH should address the engineering behind the transmission design. From experience it appears that when the transmission is under considerable load that the pedal actually gets pulled down to engage more and sometimes the lack of lubrication and spring tension is not enough to counter this force thus leaving us with a pedal that does not return to neutral on its own. I have experienced this behavior the most when I am doing intensive loader work, using hydraulics for transmission work and FEL work simultaneously.

djradz · Feb 18, 2004

Jim and All, I'm not sure the problem has that much to do with either the roller, spring or piston/damper, although I think each may have some minor contributing factor. With the tractor off or idling in range neutral and the roller lubed and spring fairly taught, my mechanism works like a charm. The spring and damper pull the pedals back to neutral very quickly. However, once the engine is running and transmissions is in gear and you're moving, even under very light load, it's a completely different story. This winter it has gotten very noticeably worse. My 40D is stored in a large garage at about 45-50 degrees. I'm not in favor of disconnecting the shock absorber because most of the rest of the year the transmission already seems to stop to quickly when I lift my feet from the pedal. This certainly seems to be a NH design flaw that could potentially kill somebody or cause serious damage. This really appears to be more of an internal problem with the transmission! /forums/images/graemlins/frown.gif

If you're lubing things up, I"d also consider not just the roller but also the outside end of the main shaft the large plate is affixed to. Just inside the "C"-clip is another friction point. As you can see in Jim's pictures, the finish has worn off this point on Jim's unit. A nice brass bushing would have been appropriate or at least a grease fitting, but neither is used here.

kensfarm · Feb 18, 2004

I haven't experienced this problem either.. just about to hit 900hrs on my TC35D w/SS. I was wondering.. since this is occuring under "heavy loads".. what are the RPM's levels you guys are running at when experiencing this problem.. is 4wd engaged? What is the level of hydralic fluid.. have you had it changed recently.. mine came back from the dealer over the fill level.. I left it that way.. hasn't seemed to hurt anything.. that was at 150hrs.. haven't changed it since.. but I do change the oil & oil filter twice a year.

I will usually run at 26 or 27 hundred RPM.. w/ 4wd engaged.. when working w/ "heavy loads".

Def. not a good situation.. w/ the hydro.. the only time I use the brakes is for parking. Hope this problem can be worked out.. please be safe!