decelerator question

[catken]

Decelerating??

Never had a Cat wrench or book tell me to decel from forward to reverse and reverse to forward. It's a full powershift and valves allow it. Up shifting under load is really a no no to decel. Done it for um-teen rears and never paid for a trans by this kind of shifting. Just my experience through the years. Talking about 6's, 7's, and 9's that I use too own.

 

[Dirtman52]

Decelerating was never an issue with a D6B but that was a long time ago. The first automatic dozers that we had were D6C dozers and Cat strongly suggested we use the decelerators when shifting. After repairing drive components on a few of them, using the decel when shifting became mandatory for our operators.

When I retired, we still used the decelerator on all our dozers when shifting from forward to reverse and vice versa, from the D5 to the 11's, no exceptions. We didn't require the engine to be completely throttled down but using it was a must. We kept it pretty simple (KISS) - No decelerator, no job.

Besides, when you get used to using it, it becomes automatic.

I can't imagine many Cat mechanics telling anyone that shifting from forward to reverse at full throttle causes no undue stress or wear on drive components, old or new dozers.

From my experience, a few pennys of prevention is worth megabucks in repairs!

 

[Countryboy]

Welcome to Heavy Equipment Forums Dirtman52! :drinkup

 

[knucklehead98]

I guess i tend to agree with the majority here. It seems to me that the D-pedal was put in the machine for a reason. Would you shift your pick up from fwd to rev at full throttle? Niether would I. We have few operators that shift without using the D-pedal, they look like rags in a dryer in there. If it was my equipment, I would send walking. The only excuse I can see for not using it is pure lasiness

 

[LDK]

False assumptions

I guess i tend to agree with the majority here. It seems to me that the D-pedal was put in the machine for a reason. Would you shift your pick up from fwd to rev at full throttle? Niether would I. We have few operators that shift without using the D-pedal, they look like rags in a dryer in there. If it was my equipment, I would send walking. The only excuse I can see for not using it is pure lasiness

tor

Whatever reason you want to pin on me for not always using the decelerator, please don't assume I'm lazy. I am the wrong side of 52 and have been running dozer's for a living since leaving school at 15 years of age and to date have never been called lazy by anyone that knows or works with me. I am known by some for getting the job done as fast as I can and having no tolerance for slackers, which category do come under?

 

[petersfamilytru]

Going nuts...

I've been operating a cat since I was a kid and the last few days have been torture. Everytime I step on the decellerator, I think of all these comments. I've never before wondered if I was doing the right thing, the wrong thing, or the worst thing... I just stepped on the damn peddle!

I need a twelve step program to de-program myself of all this information!

 

[Dirtman52]

I need a twelve step program to de-program myself of all this information!

The first step is acceptance or so I've heard. I always thought it was time for a beer. Eleven more beers after the first and you have it, a twelve step program. hic

George

 

[CascadeScaper]

The first step is acceptance or so I've heard. I always thought it was time for a beer. Eleven more beers after the first and you have it, a twelve step program. hic

George

I'm halfway through the 12 steps right now!

 

[knucklehead98]

tor

Whatever reason you want to pin on me for not always using the decelerator, please don't assume I'm lazy. I am the wrong side of 52 and have been running dozer's for a living since leaving school at 15 years of age and to date have never been called lazy by anyone that knows or works with me. I am known by some for getting the job done as fast as I can and having no tolerance for slackers, which category do come under?

I didn't meen to offend anyone, but that is what I was always told was the main reason for not using the D-pedal. I can remember my Grandfather, running a old 977 with lever steer , He would shuffle his feet between the 2 pedals to get to it.When I started running it, I got lots of butt chewings for not getting my feet in there quick enough. Lazy was thrown at more than once. It didn't take me long to learn to get them on the pedal.Same went for our old A/C HD 19with the hand clutch and hand throttle.Its there for a reason so use it,Heard that speech alot, nnot only to me, but to anyone else that dared run his babies!

 

[Deas Plant]

On Lazy Or Not Clued in.

Hi, Knucklehead98.
I once had the dubious privilege of running lever-steer 955's, both H and K series (That 955K was English-built AND powershift with lever-steer. ODD!) and an old 977H lever-steer.

Quote: "I didn't meen to offend anyone, but that is what I was always told was the main reason for not using the D-pedal. I can remember my Grandfather, running a old 977 with lever steer , He would shuffle his feet between the 2 pedals to get to it." Unquote.

To get to what? Yes, there were TWO pedals, both steering brake pedals, on those lever-steer machines. There was no decelerator pedal, only a hand throttle, unless somebody had gone to an awful lot of trouble to put in a decelerator, and where would they put it 'cos you already had a steering brake pedal under each foot? The pedal-steer machines did have a third pedal but it was 'brake-only' and activated both brakes without dis-engaging the steering clutches.

I almost always cut the revs on the hand throttle with Cat powershift track loaders before changing direction but that is just me and my neck is in pretty good shape. So were all those transmissions when I left them.

Quote: "Same went for our old A/C HD 19with the hand clutch and hand throttle." Unquote.

All I can say is that if your grandfather insisted on cutting the revs with the hand throttle on a stick-shift machine with a hand clutch before making a direction change, he would be about the only person I have ever heard of who did it. I always thought that was why those machines had a hand clutch, to make it easier to engage it smoothly and it was 'over-center' so that it would engage AND dis-engage more postively.

Or have I spent 43 years not being clued in? Am I allowed to be a little suspicious of your knowledge base?

 

[knucklehead98]

Our 977H had D-pedals on either side of the center consol, it was a trick to try and squeeze your foot between the brake pedals and the console to get to the pedal.
As for the 19, it actually has a D-pedal, but all the parts aren't there,so we use the hand throttle. Everyone that I have seen run this machine uses it the same way. As my dad always said, you have to have arms like a monkey to run that darn thing! Pretty much the same for the old '77

 

[knucklehead98]

http://www.machinerytrader.com/list...6257201&GUID=36FA018551FC432E826D35A2EF11AB5A

Found a picture of the D-pedals on a 977-H They are between the console and the brake pedals

 

[pushcat]

http://www.machinerytrader.com/list...6257201&GUID=36FA018551FC432E826D35A2EF11AB5A

Found a picture of the D-pedals on a 977-H They are between the console and the brake pedals

Ha Ha!ointlaugh

 

[JackDeere]

As far as the John Deere H series and J series dozers, you would not have to use the decel pedal. When you shift from one direction to the other the Transmission controller would ramp down the current to the PCP controls of the transmission pumps until the machine stopped and then increase the current until the pumps were in full swash in the other direction. With the multifunction valves in the circuit it would not cause any damage to the machine. The only reason you would want to decel is if you were bored and needed to exercise your foot. The later J series has a switch on the front console that allows you to decel the transmission only without lowering the engine speed. This will keep your hydrualic speed to you blade the same as you slow down the tractor at the end of a cut.

 

[AtlasRob]

Quick question for you seasoned dozer hands. I spent last week at the training grounds doing safety and orientation week. I spent one day on dozers and we were instructed to decelerate completely before changing directions, then throttling back up once the change of direction has been made. We were on Deere 650H's, a D6RXL with diff steer, and a D8R with diff steer. I always throttled down as instructed, just curious if you can change directions without doing so and not cause any harm to the machine.

Thank you for asking this question. When I first read it I was sure of the answer and expected a short sharp swift response. ( Its there use it )
It just goes to show what a broad cross section of responsible, sometimes vocal experienced members there are on this forum and I thank you all for your valuable, experienced responses. It has been educational, informative and at times amusing.
For anybody who hasn't read the whole thread, I hope you find the time its worth it.
From an operator who started on a little Track Marshall, 6 months seat time on a powershift D6 (76? vintage) 18months on an 8K and couple of months on a high drive 6H. :notworthy:notworthy:notworthy

 

[Deas Plant]

D-pedals on a 977H

Hi, Knucklehead98.
Thank you for posting that link. My edumakayshun has just been enlarged. The only 977H I ever ran didn't have that feature. Probably better for my knees and ankles without it too. LOL.

Re the HD19 with the incomplete decelerator linkage: Why not fix the d****d thing so you don't need to be an octopus to run it?

 

[knucklehead98]

We very rarely use the 19 anymore. In fact I don't think it even got started last year. I need to go get some pics of it though. The canopy on it is supported my cables, was wondering if this was a common thing or not.There is also a long story behind that tractor.If He ( its name is Rusty)could only talk!!!!!!!!!!!

 

[cr500]

Being the person who has to fix dozers, I definitley prefer them to use the decal pedal. I was in a mine in a 3rd world county where the operators NEVER used the decal pedal. They had issues with track links breaking, master bolts breaking and coming loose, sprocket segments had to be welded as the segments came loose sometimes, occaisional broken axles shafts. Transmission 1st gear usualy wore out before the hours were up. Sometimes the final drive bolts would loosen and final drive would start coming off. The operators were extremely bad and abused the machines, so maybe things wont be as bad with normal operators. (such as in Canada,US Australia etc).
Once we got a good dirt boss in and we clamped down on not using the decal pedal, these problems were reduced noticably.
It doesnt need a full return to idle or anything, just a bit of a drop in load/engine power will go a long way.
Things are especialy bad with this in some of the new dozers with bidirectional autoshift buttons. The operator will travel flat out in reverse in 2nd , the when he changes to forward, the trans switches to 1st fwd and the machine will nearly wheel stand.

 

[fabman72]

Hi guys im new here i have a 955k and the guy i bought it from had a bungie cord that he hooked to the throttle which could be why im reworking a final drive where is the decelerator located can i get one from another loader and put it in mine
thanks james

 

[Dozer575]

In over 8 years of operation of a D8 46A12,000 ish dozer, in all kinds of work, sometimes deceling and sometimes not. Even with final pinion seals leaking, engine rear seal leaking at one point in time. Never once did the transmission, bevel gears, finals need any kind of work. And this guy I worked for rarely ever changed any of the fluids. If I would never say a thing about changing oil it would have never been done. Reason 1 for wanting my own machine is I can run it how I want to and not hear "come to a complete stop and decelerate each and everytime" or what ever it is they can think up, like locking out 3rd gear.
If you ever want to watch and see SHOCK LOADING, go watch a brand new very large CNC machining center, I personally don't see how they last so long and hold accuracy with the unbelievable rapid direction changes, and alot of them run 24/7, and don't need much for work even into the 12 year range.