HST Plus DS Hi/Lo hiccup

[rScotty]

The other day an odd thing happened as I was driving the M59 back to where it sleeps.

I had been doing some backhoe crane work, & was just putting along at maybe 1800 RPM in high range with the dual speed (DS) lever in Hi. At a small incline I didn't change the foot pedal, pushed the dual speed lever down for Lo .... - and the tractor suddenly felt like I had stepped on the brakes and the engine stalled.

After checking it over I re-started and everything seems fine now - although I am not sure it is responding the same as it used to when the DS lever is in Lo.... I'm not quite sure. It sort of feels like it does in 4wd - but it's not. Like a slight bit of extra drag or if the brakes were slightly on. If anything changed, it's very slight & subtle. I usually work with the DS in Hi & set there it is just the same as always.

The next day it wouldn't start and that turned out to be a corroded battery terminal.... and that might have been the cause of the stall.

But now I'm a little suspicious of shifting to Lo & I'm wondering if anything similar has happened to anyone else with a HST+ transmission?

rScotty

 

[Smokeydog]

Not yet. Strange hiccup but you are probably right about the battery connection being suspect. Routinely shift to low in high range to climb the driveway. Back to high, high coming down.
Switching regularly hi/lo in medium range for mowing and FEL work.
Happy traxx

 

[rScotty]

Yes, it hasn't done it again. I replaced the original battery terminal connectors after it happened - had to, since they were all eaten up - I'm unimpressed with both the original battery cables and connectors. Some time before I had ordered nice battery post connectors from Amazon but hadn't put them on.

Today I was doing some maintenance and noticed that although it normally runs in Manual HST mode and slow attack, the HST optional setting had somehow changed to Auto H-DS and fast attack. So I changed it back to Manual and Slow attack & things seem normal again.

Last week the hiccup might have been three things all happening at the same time: an electrical glitch that happened just at the same moment I manually toggled the DS for LO, and also at that same moment the Auto H-DS "intelligent" shifter decided that it was time to auto-downshift to LO. So I got LO gear, but the electrical glitch shut down the motor. Hopefully it doesn't happen again.

Also took the opportunity today to remove the hand brake and switch the EGR valve back on.
rScotty

 

[wmonroe]

What do you mean “switch the egr valve back on”?

I would bet the glitch was like you stated a stack up of things that all happened at once. The corroded battery cables probably didn’t help either.

 

[rScotty]

What do you mean “switch the egr valve back on”?

I would bet the glitch was like you stated a stack up of things that all happened at once. The corroded battery cables probably didn’t help either.

The EGR valve is activated by a temperature-sensitive pressure switch. By putting a valve in the pressure line the EGR can be controlled to produce less heavy black smoke.

 

[5030]

I love black smoke...lol Tells me it's working.

 

[Fallon]

I love black smoke...lol Tells me it's working.

Black smoke is just unburnt fuel going out the exhaust. At the fuel prices these days I don't find it that entertaining.

 

[rScotty]

I love black smoke...lol Tells me it's working.

Not me. To me black smoke says the engine is struggling with a poor mixture. Probably it's struggling because I'm not in sync with the throttle and the load. Black smoke makes me think, "Oops, I can do better than that."
rScotty

 

[5030]

Your view and mine differ.

 

[rScotty]

Your view and mine differ.

Well that's fine. Hopefully it won't be the last time. It's already not the first or only...