D7E (electric) general questions

dblaneyfan · Feb 16, 2020

I’ve been considering trying out a D7E for some rough application work, have a few questions for anyone with experience with them. Not anything like pushing hardwood stumps, but perhaps some v-blade work. Stuff that is rough on nose cones and finals.

How are the final drives on these machines? Are they pretty much built for grading dirt, or can they handle some grubbing/raking?

Are there any major weak points to watch out for? Mainly looking at 2012 to 2016 model machines, but any knowledge is appreciated.

Have the generators and controllers held up well with time? Considering machines that are in the 3000 to 5000 hour range.

Thanks, db

epirbalex · Feb 16, 2020

find another model .

Tones · Feb 16, 2020

An old D7E would be much much better. Electric start pony motor or direct electric start take your pick

dblaneyfan · Feb 17, 2020

epirbalex said:
find another model .

Based on....?

Tones said:
An old D7E would be much much better. Electric start pony motor or direct electric start take your pick

Sorry, not scared of technology that works, trying to find out if this might be able to hold together for production work. I've ran those older models before, much rather operate something newer.

Tinkerer · Feb 17, 2020

I wonder what it would cost to replace the generator or motors in one of them.

Tones · Feb 17, 2020

dblaneyfan said:
Based on....?

Sorry, not scared of technology that works,

I don't think anyone is scared of technology that works.The problem is finding some that does.

Click to expand...

epirbalex · Feb 17, 2020

dblaneyfan said:
Based on....?

Sorry, not scared of technology that works, trying to find out if this might be able to hold together for production work. I've ran those older models before, much rather operate something newer.

For starters its not new tec , Russians were building diesel electric dozers decades ago . If you want a "point of difference" dozer thats alright . The last time Caterpillar went point of difference was hightrack , now cat machines are being built standard track including this one . The one 3 hours from here has issues , but ask after it and its a damn fine machine , wana buy it ? Get caught outside the caterpillar upgrades and the dozer will own you . There are plenty of low hour D7G's around world wide .

greasynails · Feb 19, 2020

Final drives will be the least of your worries with one of these. We have an early tier 3 machine that is approaching 10000 hours, and overall, it's been a good machine. I would say the frequency of break downs is actually less than a conventional machine, but when it breaks I hope you have deep pockets. Problems can be very difficult to diagnose also. My question would be what do you hope to gain by running one of these over a conventional machine. When we bought this, they advertised the power of an 8 with the fuel consumption of a 6. I think both those statements are exaggerated. With that said, our company bought a new D6XE this summer.

- They use a very high pressure nitrogen accumulator instead of a mechanical recoil spring. I have no idea why, and we've had seal issues
- At 2000 hours, the trunnions that hold the propulsion unit to the frame went out. this dropped the trans down on the final drive shafts and made a massive amount of metal. 2 new motor armatures and $62,000 later we were back up and running. (This was warranty)
- The 650V DC cables that run machine accessories are not the best. Oddly enough, I've had zero issues with any AC cables on the powertrain side
- This is the most important; If you are looking at an older machine with an electric water pump on it, you should make the seller convert to a belt driven pump. As of last summer, no more parts are available to service any of this system. If you have any failures, you will be converting to a belt pump and it is $8000 in parts. Additionally, the APC with a water pump drive socket is no longer serviced, so if you have an APC failure, you can be looking at 12-13 thousand to get back running.

With all that said, it is a very smooth and quiet dozer to run. It has good power, and we've had zero problems with the gen or the inverters. For some reason the landfills around us love these things. If you have any other questions i can try to help.

old-iron-habit · Feb 19, 2020

Just heard tonight from a higher ranked Cat employee that Cat has discontinued the D7E. The only electric machine Cat is making is the D6 version. The new numbering system is also starting. The D3, 4 and 5 is now a D1, D2, and D3. The D4, D5, and D6 will be all versions of the current D6. The straight "D" numbers continue with various machines up to D11.

dblaneyfan · Feb 21, 2020

greasynails said:
Final drives will be the least of your worries with one of these. We have an early tier 3 machine that is approaching 10000 hours, and overall, it's been a good machine. I would say the frequency of break downs is actually less than a conventional machine, but when it breaks I hope you have deep pockets. Problems can be very difficult to diagnose also. My question would be what do you hope to gain by running one of these over a conventional machine. When we bought this, they advertised the power of an 8 with the fuel consumption of a 6. I think both those statements are exaggerated. With that said, our company bought a new D6XE this summer.

- They use a very high pressure nitrogen accumulator instead of a mechanical recoil spring. I have no idea why, and we've had seal issues
- At 2000 hours, the trunnions that hold the propulsion unit to the frame went out. this dropped the trans down on the final drive shafts and made a massive amount of metal. 2 new motor armatures and $62,000 later we were back up and running. (This was warranty)
- The 650V DC cables that run machine accessories are not the best. Oddly enough, I've had zero issues with any AC cables on the powertrain side
- This is the most important; If you are looking at an older machine with an electric water pump on it, you should make the seller convert to a belt driven pump. As of last summer, no more parts are available to service any of this system. If you have any failures, you will be converting to a belt pump and it is $8000 in parts. Additionally, the APC with a water pump drive socket is no longer serviced, so if you have an APC failure, you can be looking at 12-13 thousand to get back running.

With all that said, it is a very smooth and quiet dozer to run. It has good power, and we've had zero problems with the gen or the inverters. For some reason the landfills around us love these things. If you have any other questions i can try to help.

Thanks Greasy. I am looking at upgrading a D6R III that is starting to act its age. I currently have a D6T with a regen system in operation that has been a pleasure to deal and have been looking at purchasing another, but have been intrigued by a few low hour D7E machines that I could get for a little less. With so few D7Es in operation in my area the only thing that anyone seems to be able to say about them is that it "all electric and wiring harness and computers." I appreciate the response, it is steering me away from considering a D7E, mainly because of the lack of mechanics with experience and knowledge in my area, think I will stick with what I know for now.

By the way, now is the XE holding up for you? I saw some Youtube videos promoting it last summer, but haven't seen any operation stuff.

greasynails · Feb 25, 2020

It is all electric and wiring and control modules, but show me anything that isn't anymore. So far so good on the XE. We have close to 900 hours with some wiring issues on the accugrade but nothing else. It likes the DEF since Cat eliminated EGR, but I'll take 8 gallon of DEF a day over the EGR problems we've had. Looks to be a much easier machine to work on if we have problems.

satkinson · Mar 1, 2020

There have been a large batch of 2012 D7E LGPs sold through Euroauctions in the uk the past few months, these Dozers ranged in hours from 25-36000 hours.
I was amazed when I saw the meter readings on them, I thought they must be pretty tough machines to notch up those kinds of hours but I guess they could have cost a ton to get to that point.

old-iron-habit · Mar 1, 2020

satkinson said:
There have been a large batch of 2012 D7E LGPs sold through Euroauctions in the uk the past few months, these Dozers ranged in hours from 25-36000 hours.
I was amazed when I saw the meter readings on them, I thought they must be pretty tough machines to notch up those kinds of hours but I guess they could have cost a ton to get to that point.

Waste Management was to have been the largest user of D7Es in the nation using them in the landfills. They probably did well in that environment. They would put that kind of hours on and probably not that hard of a life compared to a construction site. I wonder if they got shipped over for resale?

satkinson · Mar 2, 2020

old-iron-habit said:
Waste Management was to have been the largest user of D7Es in the nation using them in the landfills. They probably did well in that environment. They would put that kind of hours on and probably not that hard of a life compared to a construction site. I wonder if they got shipped over for resale?

Sounds feasible I'm sure everyone of them had a winch fitted for some reason.

Blocker in MS · Mar 2, 2020

old-iron-habit said:
Waste Management was to have been the largest user of D7Es in the nation using them in the landfills.

That is a little funny. The WM guys in our state are all addicted to 6T’s with a few high track 7’s and a couple 8T’s.

The last cell I was involved in the landfill guys were complaining because they were going to have to try out a brand new D85. They thought the low track design would never work. They thought the trash pack in the tracks and not have enough room to fall out so they would be cleaning tracks all the time. I saw the machine show up, but was finished and never heard if they changed their minds or not.

old-iron-habit · Mar 2, 2020

Blocker in MS said:
That is a little funny. The WM guys in our state are all addicted to 6T’s with a few high track 7’s and a couple 8T’s.

The last cell I was involved in the landfill guys were complaining because they were going to have to try out a brand new D85. They thought the low track design would never work. They thought the trash pack in the tracks and not have enough room to fall out so they would be cleaning tracks all the time. I saw the machine show up, but was finished and never heard if they changed their minds or not.

Cat personnel told us this 3 years ago during a ACMOC plant tour when they had a number of them going together on the assembly line. They said that they were working out exceedingly well in landfills and that Waste Management owned the majority of the ones built to date.

Blocker in MS · Mar 2, 2020

I do not doubt that at all Old Iron

I thought it was funny that they were convinced the 85 would not work. I would have loved to had someone bring me that dozer....or a 7E for that matter as long as they did not want me to make the payments

D7E (electric) general questions

dblaneyfan

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epirbalex

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Tones

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dblaneyfan

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Tinkerer

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Tones

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epirbalex

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greasynails

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old-iron-habit

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dblaneyfan

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greasynails

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satkinson

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old-iron-habit

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satkinson

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Blocker in MS

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old-iron-habit

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Blocker in MS

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