New TN already malfunctioning-help?

[oldforestor]

My new tn75d-well, new to me with 600 hours has a light on that looks like this...(O)... except with an exclamation point in the middleof the circle /forums/images/graemlins/confused.gif. They "forgot" my manual. They say it's no big deal, but the power shuttle keeps poppin into neutral. Im about to send it back... any ideas before I get real mad. This machine was supposed to be fully "checked out" and ready to work.

 

[hazmat]

Not sure what the light is, could be oil press, overheat, battery or glow plug. Hope you get it fixed. Take a deep breath, count to 10 and think of your happy place /forums/images/graemlins/tongue.gif

Good luck

 

[RHughes]

That's the warning light for the brake fluid level. Check the reservoir and top it off if needed. If the fluid is up to the fill line, then the sensor is probably just bad. If the level keeps dropping, then you've obviously got a leak somewhere.
My TN65 had a slow leak around a fitting on the master cylinder. The brakes never stopped working, but the light was annoying.

Be sure to new the NH brake fluid and *NOT* the stuff that you buy at a parts house or Walmart. The fluid for the tractor is petroleum based and *not* alcohol based.

 

[mahlers]

I may be totally wrong about this - but I seem to remember reading that the EHSS system will pop into neutral if your brakes are showing a serious fault. I'll look at my manual when I get home...

 

[RickB]

TN's with hydraulic clutch packs are called Power Shuttle, a similar but different system than the TC48/55 and 2120's EHSS. Neither system is connected to the braking system. The problem with the Power Shuttle is probably purely mechanical. The lever/switch should be replaced, and the cowling and lever boot carefully examined and filed where necessary to ensure the new lever is allowed to latch into its detented F or R position. Of the three dozen or so tractors we have sold with Power Shuttle, I have seen this problem on one unit. The dash indicator lamp is the brake oil warning lamp, as described. For it to come on for the first time at 600 hours indicates normal breakin and piston travel within the brake system. Not a cause for panic; merely a request for normal maintainence. Tractors that were not properly pre-delivered will throw that light at less than 100 hours.

 

[AndyMA]

I mostly agree with Rick's explanation however I want to add a little with my experience with a TN75D and a TN75S with the same transmission. If you engage the shuttle lever before you select a gear with the tranny lever, the system detects a fault and shifts the shuttle back into neutral. The dash indicator indicates a shifting fault. Selecting the gear (1,2,3,4) before shuttling forwar or reverse corrects this error condition. It drove me crazy until I figured it out. The manual confirms this operation.

Andy

 

[mahlers]

</font><font color="blue" class="small">( TN's with hydraulic clutch packs are called Power Shuttle, a similar but different system than the TC48/55 and 2120's EHSS. )</font>

That's interesting - I figured they were the same system but different names.

 

[mahlers]

</font><font color="blue" class="small">( If you engage the shuttle lever before you select a gear with the tranny lever, the system detects a fault and shifts the shuttle back into neutral. The dash indicator indicates a shifting fault. Selecting the gear (1,2,3,4) before shuttling forwar or reverse corrects this error condition. It drove me crazy until I figured it out. The manual confirms this operation. )</font>

Thanks Andy - you saved me some time in searching through the manual to figure out where the "shift fault" issue stuck in my mind. I had the same experience that you did with the shuttle popping back to neutral if I wasn't in gear. It seems like it would also make sense for the transmission to shift into neutral if there was some other major fault (like a brake fault), but apparently those systems aren't interconnected.

 

[RickB]

To clarify Andy's comment, he is correct about the shifting sequence relative to the gearshift and shuttle lever. However, selecting a shuttle position prior to a gear simply throws a flashing amber lamp with a gear icon indicating a disabled transmission. The cure is as Andy described. However, there is no mechanism for the PowerShuttle system to physically move the shuttle lever to 'N'. The lever will remain in F or R until placed in N by the operator, unless it is randomly forced to N by pressure exerted on the lever boot by the plastic cowl, as experienced by a few tractors, among them the original poster here. Mechanically, the EHSS and PowerShuttle systems are very similar. Electronically, The PowerShuttle system is far more complex with more control inputs and failsafes built in. I am a very big fan of this system, some folks are not.

 

[mahlers]

</font><font color="blue" class="small">( Electronically, The PowerShuttle system is far more complex with more control inputs and failsafes built in. I am a very big fan of this system, some folks are not. )</font>

I'm a giant fan of this system, too. I was afraid at first about the complexity of the system, but from what I understand it's very reliable. I figure I will have to be ready to do some serious head-scratching one of these days when the warranty is expired and I can't afford to bring it to a shop, though. It's too bad they don't have an OBDII port on these tractors - using a DRB scantool has helped me diagnose and fix a ton of very mysterious car problems, and I wish they had something similar for tractors.