L3400 Hour Meter Inaccurate

[Goog]

Maybe nobody else has noticed but I always thought that I was putting on more hours on my tractor than my hour meter showed so I timed it.

After 1.8 hrs engine running time the hour meter counted 6 tenths. Some working and also idling. A mix of rpm.

I asked my dealer and he said "yup". It is only accurate at pto rpm which is about 2100-2200 or so. I rarely run it that fast as I am usually moving hay bales or whatever and don't feel the need to rap the engine that high.

So now I wonder how many hours that I really have on it and how this affects my service intervals. I ordered a Hobbs electric hour meter that I am going to install. If the engine is running I want it counting every tenth of run time.

Maybe everyone other than me new this? We have Kubota mowers where I work and they have electric hour meters and they work normally. Key on it is counting.

Maybe this is one of those things we have to live with on our low end tractors compared to the Grand L's but I don't like it and wished I had timed it sooner.

What do you all think? Brian

 

[rdsaustintx]

Methinks you have an RPM-compensating hour meter, which is a high-class problem. It doesn't affect your service intervals, it makes them more accurate. Wish I had one.

RDnT

 

[john_bud]

Let me get this straight, you have the best known method of calibrating engine work to maintenance intervals ---> and you want go back to one that is wildly inaccurate? Just tugging your chain a bit....

Seriously, the meter you have is a revolution counter that is correlated to time when the engine is running at a specific RPM.

For instance, my tractor is accurate at the PTO speed of 2600 engine rpm. In one hour at that rpm, the engine completes 2600 x 60 revolutions (156,000). Service intervals could be listed at 7.8 million revolutions and 31.2 million revolutions then every 31.2 million after that, but calling it 50 and 200 hours is easier for most folks. Your electric meter, only tells you that your key was on.

Here are some unlikely scenarios for example:
Let's say you were filling the tank on Friday morning and ran out of fuel in the 5 gal jug. You turn the key on to see how full the tank is and go to fill up the 5 gal jugs. You get side tracked and don't finish refilling the tank until the next Saturday evening. The key was on the whole time and the meter now reads 200 hours more. So, do you rush to the Kubota store and buy 10 gal of SUDT, 6 qts of oil, engine filter, hydraulic filter, HST filter and a new fuel filter? How about if you normally run the tractor at 1200 rpm for pulling a small hay trailer around. When you are putting out hay, you idle down the engine. The engine is averaging 700 rpm while you move the trailer then put out the hay. After 200 clock hours, the engine has only seen 700 x 60 x 200 revolutions. 8.4 million for the math challenged. Then let's say the next month you are doing FEL work at the limits of capacity and you have a major time constraint so you have the engine jacked up to the highest rpm it will go (3000 rpm). At the end of the month you have 200 hours all done at 3000 rpms. That's 3000 x 60 x 200 revolutions. 36 million revolutions. The clock based hour meter is showing the same 200 hours added in each case, but the Kubota meter shows 0, 53.8 and 230.7 added hours in each scenario. Which type of meter is giving you a better indication of the amount of work the tractor has done and if it is in need of service or not?

I hope this didn't come across harshly -- it was meant to be a tongue in cheek humorous reply. Completely factual, but humorous!

jb (not a threat to professional comics anywhere)

 

[Goog]

I do see what you are talking about but not sure I totally agree. If an engine is idling for an excessive amount of time the hour meter will never show it but your oil may get extremely dirty.

By the way. I like your calculations and I see what you are saying about engine revolutions but I thinke that there is more here than just engine revolutions.

Not saying I let my tractor idle alot but most equipment with an hour meter counts total run time be it idle or wide open throttle.

I have been a boater in the past and everthing on them is based on actual key on hours and maintenance is based on that time. Yes, the key was left on a boat once. Oops.

I think that kubota must be assuming that you always run at pto speed or close to it and then everything would be great. I don't.

I still am going to add an electric hour meter and watch the 2 of them and really confuse myself.

Thanks for your input. That is exactly why I am asking and I can admit I am wrong. Just need to think about it some more. I am an ASE and Ford Master Technician and now work for a city shop and we do evertyhing by hours or miles. Brian

 

[john_bud]

Goog,

There isn't a perfect way. Miles, hours, revolutions, gallons of fuel used, time / temperature curves for the oil --> many ways of doing it.

Premium and industrial equipment often uses the rpm based hour meter. You may want to nose around abit at the shop and check which type is used. No matter what meter is on your tractor, I'm sure it will be maintained on time and with great care. That is the main point. With both type on the same machine, you will better understand it's utilization - that's a big plus.


Enjoy the ride!

jb

 

[DK35vince]

After 1.8 hrs engine running time the hour meter counted 6 tenths. Some working and also idling. A mix of rpm.

I asked my dealer and he said "yup". It is only accurate at pto rpm which is about 2100-2200 or so.

Most tractors that I have been around or used have this type of hour meter.(hours based on engine RPM's)
Both of my current tractors use this type of hour meter..

So now I wonder how many hours that I really have on it and how this affects my service intervals.

The owners manual will show service intervals for that machine. Thats what you should use.

 

[art]

Maybe nobody else has noticed but I always thought that I was putting on more hours on my tractor than my hour meter showed so I timed it.

After 1.8 hrs engine running time the hour meter counted 6 tenths. Some working and also idling. A mix of rpm.

I asked my dealer and he said "yup". It is only accurate at pto rpm which is about 2100-2200 or so. I rarely run it that fast as I am usually moving hay bales or whatever and don't feel the need to rap the engine that high.

So now I wonder how many hours that I really have on it and how this affects my service intervals. I ordered a Hobbs electric hour meter that I am going to install. If the engine is running I want it counting every tenth of run time.

Maybe everyone other than me new this? We have Kubota mowers where I work and they have electric hour meters and they work normally. Key on it is counting.

Maybe this is one of those things we have to live with on our low end tractors compared to the Grand L's but I don't like it and wished I had timed it sooner.

What do you all think? Brian

Brian the tach on the 3400 is just like all tractor manufacturers built till electronics entered the tractor industry. They do read at the PTO speed as most tractors were built and are considered to run at that speed for field work. Since the change to the electronics they add depending on jobs many more hours to the tach on some jobs up to double. It does make a difference on oil changes as many of the electronic tach units are getting close to 500 hour oil changes in some applications with the right oils. Oil quality has improved but I'd still hesitate to go much past 200 hours on an old style tach with the best of oils unless it was under the right application.

 

[ccsial]

Hi Goog,

This is very normal. Aircraft do the same thing. My airplane has three hour meters. One reads actual hours and is called air frame hours. The others read revolution hours and is called tach hours. All the engine maintenance is based on tach hours. It is a good system. As was mentioned, higher class.

My1910 and L3400 read tach hours but my JD355D reads actual hours. I guess they figure that garden tractors run at max RPM most of the time.

 

[Marcussen]

The L2800 hour meter is the same, only accurate for clock time at 2300-2400 rpm. Maintenance should be based on the hours registered on the tractor hour meter. They are pretty conservative (oil change every 100 hours etc.) for that tractor anyway. (except I would change filter every oil change).

This has been discussed before, and is the same for all tractor manufacturers (with some exceptions for economy tractors).

 

[Taiser]

Interesting...

anybody know off hand which models have this meter? My B7800 for instance ?