Beware cab owners: PTO hp is NOT same with a cab.

[cowboydoc]

I recently bought a JD 5420. 81 hp and 65 hp at the pto. The problem is they rate these tractors without a cab. Running the ac and other things associated with the cab takes quite a bit of hp. Last week I was baling some hay and was having a tough time going up hills without downshifting. It was a hot day and ac was running full blast. I was quite comfortable in the tractor but I was concerned about the hp.

After I was done baling I called the dealer and he said they'd come out and pick it up and put it on the dyno. Without air or anything in the cab on the tractor pulled 67hp on the dyno. BUT when you turn the air and all the electrical accessories on in the cab things went down in a hurry. With the stereo, lights, ac, etc. running it dropped the pto hp down to 56 hp. No wonder I was having troubles.

Without the cab I would have been fine. Deere so far has been pretty good about it. It looks like they are going to buy the 5420 back and let me get a 6415. This will give me plenty of hp.

The cab pto hp was even news to the dealer. They had never thought of it either. In the bigger tractors they are usually 20 hp or more over the rated pto hp to account for the cab. He said in the cutthroat world of the smaller tractors that obviously isn't the case. If you're considering a cab keep this in mind about the decreased pto hp with a cab.

 

[Docsknotinn]

Is there any standard mathematical equation to calculate HP loss when a short fat bald guy like me gets in ???? /forums/images/graemlins/shocked.gif Dave

 

[cowboydoc]

Not sure but I'm meeting with the Deere engineer and a customer relations specialist at 6:00 tonight and I'll ask them. /forums/images/graemlins/wink.gif

 

[RobS]

I guess I'm not surprised by this Richard. In the auto industry these are called "parasitic losses". The power to run the AC, power steering, alternator and such has to come from somewhere so the engine output is reduced. Naturally, the manufacturers are going to advertise all the power they can so they test with the accesories turned off.

It will be interesting to hear what Deere says about it. Certainly admirable of them to buy it back /forums/images/graemlins/smile.gif

 

[Docsknotinn]

Richard, If you could kindly get some real complex formula it would be most helpfull. I too would like to trade up and I can use all the "scientific" help I can get to convince the gate keeper. /forums/images/graemlins/smirk.gif I am very pleased to hear that they are willing to work with you to get you just the machine you want/need. That's something that can no longer be taken for granted from any large corp. A BIG perk !! I am not suprised that you do have some loss but I am more than a bit chagrined that it is that much. If it were me there might have been a little initial tire kicking goin on. Not a happy experience after spending the big bucks But It is good to hear they are working it out. Do they have the other machine in stock so you dont loose any field time ? Dave

 

[cowboydoc]

Dave,

It was really a shock to them as well. They had no idea with the cab and neither did I. The required pto for the baler was minimum 55hp. At 65 pto hp on this tractor we figured we would be fine. I did run the tractor before and it seemed great. It still is a great tractor. With the 12' mower and other things no problem at all. Plenty of power. It was just going up the hills in B range in third gear. In second gear it would pull it but not third. That's only 7 mph which they agreed you should be able to bail at. And without the cab and the extra 10 hp you would have been.

I can't complain though so far they are being very good about it. We'll see tonight when we meet to discuss the specifics of the trade.

 

[Bird]

I'm not surprised at all that there was some power loss, but I sure would have expected 5 hp or less; not 12 hp. /forums/images/graemlins/shocked.gif Of course I guess that just shows how little I know about cab tractors. /forums/images/graemlins/laugh.gif

 

[Docsknotinn]

Cowboy, I have your problem solved. Just buy my 2210 and tow it with yours. Its 17 pto HP so it should be just about right to run your AC/ lights etc and Then I can get a 2210 /forums/images/graemlins/grin.gif Dave

 

[yellowsocks93]

Thanks for that info Cowboydoc. We have a 5320 with Cab and love it but we are just about to get a John Bean airblast sprayer and that PTO info will come in handy to see if we can handle it. We were 10 HP above minimum but I don't know now with the PTO drop. I'll have to put it on the dyno at work. How much is the price difference for the new tractor? JD giving you a discount?

Nick
990 4x4 turf, 272 RFM, 430 loader, 25A flail

 

[cowboydoc]

Yea I'd be interested to see how much yours drops compared to mine.