Pull scraper questions

We are plumbing an older D7F to pull a scraper behind. I have a couple of small pond dams to build. Knowing very little of this application i thought i might inquire this forum. First question is the type and size that should be used behind the D7? Should we be using the version with the front dolly wheels typical of the cat 70 or 80, or should we go to the style with no dolly wheels such as the new Reynolds or Ashland. Are there any drawbacks to the dump style over the ejector. We have another contractor in the area with a older Garwood or "Allis" as he calls it. I have been looking for info on these but i am not coming across much. It appears to be in good shape but i'm wondering why there is so little info on these, like they where short lived or problematic. Last but still very important is capacity, the material will be clay mostly taken from a hilltop that should be relativley dry. Any help would be helpful.

Cant help with size, or dolly wheels, and I've never ran a dump style pan, But I can tell you this...

NOTHING is harder to get out of a terex's bowl than wet clay, stuff likes to roll up into a log so to speak and not come out.

One other driver said he had some success doing this, open up the apron, run the ejector front, while going foreward in first, slam it into reverse, and mash the pedals, oh, and make sure the mechanic and boss are no where to be found.... me, my pan had a little bit of brakes left and I'd sometimes use them to flop the "log" out. While reverse might work, it also is really hard on drivelines

I used to run a D7F with a No. 70 Cat scraper. We live in an area with heavy clay soils and used to dig a lot of ponds. That scraper was more than enough for the D7 to handle. It had extensions on it so the bucket was rated at around 13 yards heaped, as I recall. We could generally only fill it to overflowing if we had a pusher.

As for the hitch, I would go with a front dolly. At one point, we actually broke the hitch off while pulling the scraper, so that leads me to believe that the standard D7 hitches are not designed with enough strength to support a scraper with no front dolly.

As for the dump design of the scraper, I always preferred the Cat or anything that had a push-style ejector because of the lower center of gravity. Many years ago we had a couple of Bucyrus-Erie scrapers with a bowl that pivoted upwards to dump. It was possible to tip them over on level ground while dumping just by driving over a big lump of mud.

With a Cat D7F a Cat No.70 or Cat No.435 would be quite adequate.
Both were designed for use behind the D7.

I'm personally not too fond of the newer type (with no front axle).
The older style machines are more robust and the ejector allows you to have greater control over dumping:IMO

Chris Howard said:

We are plumbing an older D7F to pull a scraper behind. I have a couple of small pond dams to build. Knowing very little of this application i thought i might inquire this forum. First question is the type and size that should be used behind the D7? Should we be using the version with the front dolly wheels typical of the cat 70 or 80, or should we go to the style with no dolly wheels such as the new Reynolds or Ashland. Are there any drawbacks to the dump style over the ejector. We have another contractor in the area with a older Garwood or "Allis" as he calls it. I have been looking for info on these but i am not coming across much. It appears to be in good shape but i'm wondering why there is so little info on these, like they where short lived or problematic. Last but still very important is capacity, the material will be clay mostly taken from a hilltop that should be relativley dry. Any help would be helpful.

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you need the dolly wheels to keep from wearing your rollers out, the 3W Cat 70 flat bottom would be ideal it is 13 yard, the round bottom earlier one was 11 yard. A 314 LaPlante Choate would be ideal if using cable, the choate's were best ever in mud or sticky clay. not sure what any of those are like converted to hydraulics, but the cats were hard to unload, loaded harder too and heavy to pull around. I pulled cats, isaaccson and choates with cable control, the choates were the best of any, could have been built a little heavier though, they were bought out by allis chalmers. the old letorneau's were okay as far as i know, little top heavy

Cat 70 with front dolly your best bet. Use them here behind D7E's and G's. No experience with F's. Have the side boards and the E's handle them good. Very seldem do we need to push. As to Cat type ejector or someone else's dump style only one way to go. Ejector, ejector or you can go for ejector like the Cats are.

Chris Howard said:

We are plumbing an older D7F to pull a scraper behind. I have a couple of small pond dams to build. Knowing very little of this application i thought i might inquire this forum. First question is the type and size that should be used behind the D7? Should we be using the version with the front dolly wheels typical of the cat 70 or 80, or should we go to the style with no dolly wheels such as the new Reynolds or Ashland. Are there any drawbacks to the dump style over the ejector. We have another contractor in the area with a older Garwood or "Allis" as he calls it. I have been looking for info on these but i am not coming across much. It appears to be in good shape but i'm wondering why there is so little info on these, like they where short lived or problematic. Last but still very important is capacity, the material will be clay mostly taken from a hilltop that should be relativley dry. Any help would be helpful.

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Would love to see some pictures of what you ended up doing. Very interested in seeing your structural hitch, and how you managed to hydraulically plumb. I'm considering doing the same with my D8, and would appreciate knowing your success, before i start a failure! Thanks

One other thing. If using a Cat 70 or 435, reinforce the gooseneck. The old 70's were not built for the higher horse power of the D7E's, F's and G's. It is possible to tear them apart.

The CAT 70 runs well behind any D7, the 435 is often pulled behind D8H/K tractors without any trouble or any need to add plates to the neck?? but the 435 is harder to load and un-load than the 463 behind a D8, the 70 is a good bin to pull and light enough to match the D7 and is the correct unit for these tractors.
tctractors

Does anyone have any pictures on how the Hydraulics hook up to a CAT Dozer from the scraper? Where would the Ejector Extend/Retract, Gate Open/Close, and Bowl Up/Down functions get hooked up?

You're going to either have to drop the blade and use those functions, or add/utilize the ripper valve. The ripper circuit is used for the bowl, and a diverter is put in the tilt circuit to run the apron/ejector.

You will want an ejector, wet or dry you can always get the material out. Go with a dolly behind a track machine, easy to hook up and you won't need the extra weight for traction. A good old scraper when converted right are the letourneau ls or fp, the ls would be a great size match. The cats are good pans but will overturn or bog down faster than the letourneau.

Yair . . .

The cats are good pans but will overturn or bog down faster than the letourneau.

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Really? . . . . I have never ever heard that sentiment before.

Cheers.

We have run cat 463, 60, Reynolds 15.5, Wooldridge, letourneau fps, cat 621, 615, 623 and the fp's will do better in the mud and ride a slope bettert Han all the rest, in our experience.

Chris Howard said:

We are plumbing an older D7F to pull a scraper behind. I have a couple of small pond dams to build. Knowing very little of this application i thought i might inquire this forum. First question is the type and size that should be used behind the D7? Should we be using the version with the front dolly wheels typical of the cat 70 or 80, or should we go to the style with no dolly wheels such as the new Reynolds or Ashland. Are there any drawbacks to the dump style over the ejector. We have another contractor in the area with a older Garwood or "Allis" as he calls it. I have been looking for info on these but i am not coming across much. It appears to be in good shape but i'm wondering why there is so little info on these, like they where short lived or problematic. Last but still very important is capacity, the material will be clay mostly taken from a hilltop that should be relativley dry. Any help would be helpful.

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Here is a video of a D8T pulling a 28 cubic yard scraper, direct mounted on rear of the dozer frame:
https://www.youtube.com/watch?v=QEu-Eqv6V6A