startinghandle
Member
why would brake on one side only want renewing, I suppose the obvious answer it has been turning a lot more in one direction than the other!! what is age of crawler??
Cat D7D restoration
- Thread starter diesel1
- Start date
startinghandle
Member
I have just thought of something,...you say that just one steering brake needs renewing but would it be good idea to do both sides while you have access ??
diesel1
Member
- Location
- North Yorkshire
Normally i would agree, but the other brake band is in reasonable condition. I will be able to adjust the brakes so that both brake pedals feel and brake the same. Its not as tho the D7 is going to be doing lots of hours each year.
You never need to brake with both pedals at the same time, unlike a car where both left and right brakes have to be the same or the car would pull one way.
Zetor
Member
- Location
- Northumberland
Does anyone have experience of a D6d dozer early seventies? Looking to buy but not a clue what to look for
Thanks
Thanks
diesel1
Member
- Location
- North Yorkshire
Powershift or direct drive, personally i would always go for a direct drive dozer with machine this age, easier and cheaper to repair, earlier in the year i bought a massey ferguson 3366 dozer for scrap value, it ran good when cold but after 5minutes it would not want to move, after removing some parts on the torque converter it was found that the piston in the hydraulic reverser control valve was sticking due to some iron filings, works fine now.
Anything more serious like torque converter removal and it would have not got repaired. No new or secondhand parts available for this model anywhere.
Running gear is the main thing to look at i would say, i wouldnt buy anything with bad running gear due to cost to replace, everything else is usually repairable.
Pull the floor plates and check for oil leaks when steering either way.
Im sure other people have more input.
Fowler VF
Member
- Location
- Herefordshire
I bet its the left brake that's worn. With a trailer plough a good driver would always turn left to avoid straining the land wheel, even if you need to turn right on the headland you should do a left hand double loop. Even on non-ploughing crawlers I often find its the left brake worn, an inexperienced drive tends to keep dabbing the left brake as he looks for the clutch!!
You are sort of right about the brakes not needing to be balanced on a Cat with clutch and brake, but the older Marshalls had a diff in them, very important that the brakes are balanced otherwise they quietly veer off as one brake drags the diff across.
By the way, make sure you sort out the main shaft clutch brake, otherwise you will struggle to slow the gearbox down to get it into gear.
Fowler VF
Member
- Location
- Herefordshire
make sure you work that D7 hard; its amazing what they will pull!!!!
tomlad
Member
- Location
- nr. preston
Sorry to hijack
Would all trail ploughs have a , I'm unsure terminology, rake adjuster ?
I was fortunate enough to be allowed to drive a steam tractor other month , we were struggling with lining plough up on entry . No adjuster fitted yet . Land not level so plough always entering down hill on plough side . Straightened out 10 yard in .
4 fr ransomes.
Driver said didn't have prob last time out , level field .
Would all trail ploughs have a , I'm unsure terminology, rake adjuster ?
I was fortunate enough to be allowed to drive a steam tractor other month , we were struggling with lining plough up on entry . No adjuster fitted yet . Land not level so plough always entering down hill on plough side . Straightened out 10 yard in .
4 fr ransomes.
Driver said didn't have prob last time out , level field .
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diesel1
Member
- Location
- North Yorkshire
Its the righthand side, i put it down to leaving the park brake on too many times and forgetting, park brake is on the right only.
I could have put all new brake bands on, also new steering clutch plates while im in there, but you have to draw a line somewhere on what to replace and what not to.
Yes, the main clutch brake needs attention, this will be removed in a day or two, after its had some more parts removed and been powerwashed.
Fowler VF
Member
- Location
- Herefordshire
Presumably you are ploughing in the furrow? i.e. the tractor wheel running down in the open furrow. Crawlers usually plough on the land, so you just drive a bit wide at the opening to compensate and keep the plough wheel in the right place if it drifts downhill. You can do something similar with a wheel tractor, but only with a trailed plough, with a trailed plough its the wheel on the plough being in the right place that is critical and governs the front furrow width, but on a mounted plough its the distance between the tractor wheel and front furrow that governs it. So you might be able to compensate by driving wide at first, with the tractor wheel not quite in the furrow, but this can be counter productive as the tractor wheel will cut the furrow wall and make the front furrow odd. A trailed plough has a tendency to crab when running empty and only swings back into true line once it has resistance in the soil, you set up the drawbar according to this when its running. On a slope this difference in line between running empty and running full will be more exaggerated. It might be that you haven't got the drawbar correct for the working position, or might have to over compensate for the slope. You can do this by adjusting the attachment point of the drawbar onto the hake bar (bar across the front of the plough) and more so by changing the position and/or length of the cross bar (long side of the triangle). In full work the drawbar should normally run parallel to the work, plough shouldn't crab and the landsides should be parallel to the furrow walls. hard to explain! Many ploughs will also have an adjustable cross bar with a lever on them, you will see match plough men pushing the plough across as they enter work and then swinging it back to normal after a yard or so. You will also see match ploughmen with an adjustable hitch on the tractor that will move the hitch point across either way. This might also help you to align the plough on entry.
By the way, did that tractor come from Cornwall?
By the way, did that tractor come from Cornwall?
diesel1
Member
- Location
- North Yorkshire
I bought the tractor from euroauctions leeds two weeks ago, after doing a bit of serarching on the net, i saw it had been in a auction back in september which made me a little warey at the time.
I made a good decission to buy it! Not found any major probrems with it that cannot be fixed yet.
Fowler VF
Member
- Location
- Herefordshire
Question about the tractor was aimed at the guy with the Foden, asking about setting the plough up!!
Is you Cat actually a 7D? What engine is in it?
Is you Cat actually a 7D? What engine is in it?
Guy_Incognito
Member
- Location
- Herefordshire
It had been on eBay for months as well, I spoke too the chap selling it about some tracks he was from down London way
They called themselves Total Trading LTD
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diesel1
Member
- Location
- North Yorkshire
Yes, Cat D7D serial no. 17A14739 Cat D339 engine
diesel1
Member
- Location
- North Yorkshire
Not much to look at but will post a picture when its out, think its supposed to have a brass lining but i stand to be corrected.
Fowler VF
Member
- Location
- Herefordshire
The D7 3T, D7 4T and D7 6T were introduced in mid-1944.
The machines incorporated several improvements that Caterpillar engineers had developed but were unable to introduce due to the necessity of maintaining production of the existing 7M for WWII requirements.
As the urgent demand for tractors subsided these improvements made their way into series production.
The D7 4T was built solely for the US Army while the D7 6T was built for the US Navy.
This enabled Caterpillar to fulfill military contracts that had been let but not completed.
Just over 7500 D7 4T’s were manufactured before the type was discontinued in 1948, and an unknown number of D7 6T’s.
The fate of many of these military D7’s is quite sad as many were pushed into vast pits of surplus equipment and buried while others were just driven into the jungle and left there, some with very few hours on the clock.
This wholesale “jettisoning” of unwanted equipment is what makes the D7 4T a somewhat rare type these days and the D7 6T even rarer.
There is hardly any difference between a D7 3T, 4T or 6T other than the optional external attachments applied to it.
A highly successful variant.
Between 1944 and 1955, Caterpillar manufactured over 28,000 D7 3T models.
With the trusty Caterpillar D8800 engine initially providing 93 flywheel horsepower, this was increased to 108 flywheel horsepower around 1952.
One of the new features Caterpillar had introduced was a forward/reverse lever into the transmission meaning the operator didn’t have to repeatedly shift gears all the time when changing direction.
Other improvements added along the way was Caterpillar’s famous oil clutch and a two-position front idler which better set the machine up for trailed or pushed attachments.
D7 3T’s can still be found doing occasional work some sixty years after the last one left the production line.
The next step
With the D8800 diesel engine now at the upper reaches of it’s development potential, Caterpillar introduced a new version of the D7 in 1955.
This was the legendary D7 17A series, (also known as the D7C).
This featured the all-new Caterpillar D339 four-cylinder diesel engine rated at 128 flywheel horsepower and incorporating all the better features of the previous 3T model including oil clutch, forward/reverse lever plus the addition of the newly developed hydraulic track adjusters, a great labour-saving device which most people take for granted these days.
Halfway through the machines extensive production term, Caterpillar made two crucial changes to the machine.
At serial number 17A11981, a turbocharger was added to the engine, boosting output to 140 flywheel horsepower and allowing the machine to work at higher altitudes without engine de-rating.
Caterpillar also fitted oil-cooled steering clutches and brakes which greatly extended the service life of these components.
Although Caterpillar did not change the serial number prefix of the new improved D7 17A, it did get a new designation of D7D.
These later D7D’s have a distinctive engine note which sets them apart from all other D7’s.
Production of the D7C/D7D had exceeded 19,000 machines when the last one came off the line in 1961.
The machines incorporated several improvements that Caterpillar engineers had developed but were unable to introduce due to the necessity of maintaining production of the existing 7M for WWII requirements.
As the urgent demand for tractors subsided these improvements made their way into series production.
The D7 4T was built solely for the US Army while the D7 6T was built for the US Navy.
This enabled Caterpillar to fulfill military contracts that had been let but not completed.
Just over 7500 D7 4T’s were manufactured before the type was discontinued in 1948, and an unknown number of D7 6T’s.
The fate of many of these military D7’s is quite sad as many were pushed into vast pits of surplus equipment and buried while others were just driven into the jungle and left there, some with very few hours on the clock.
This wholesale “jettisoning” of unwanted equipment is what makes the D7 4T a somewhat rare type these days and the D7 6T even rarer.
There is hardly any difference between a D7 3T, 4T or 6T other than the optional external attachments applied to it.
A highly successful variant.
Between 1944 and 1955, Caterpillar manufactured over 28,000 D7 3T models.
With the trusty Caterpillar D8800 engine initially providing 93 flywheel horsepower, this was increased to 108 flywheel horsepower around 1952.
One of the new features Caterpillar had introduced was a forward/reverse lever into the transmission meaning the operator didn’t have to repeatedly shift gears all the time when changing direction.
Other improvements added along the way was Caterpillar’s famous oil clutch and a two-position front idler which better set the machine up for trailed or pushed attachments.
D7 3T’s can still be found doing occasional work some sixty years after the last one left the production line.
The next step
With the D8800 diesel engine now at the upper reaches of it’s development potential, Caterpillar introduced a new version of the D7 in 1955.
This was the legendary D7 17A series, (also known as the D7C).
This featured the all-new Caterpillar D339 four-cylinder diesel engine rated at 128 flywheel horsepower and incorporating all the better features of the previous 3T model including oil clutch, forward/reverse lever plus the addition of the newly developed hydraulic track adjusters, a great labour-saving device which most people take for granted these days.
Halfway through the machines extensive production term, Caterpillar made two crucial changes to the machine.
At serial number 17A11981, a turbocharger was added to the engine, boosting output to 140 flywheel horsepower and allowing the machine to work at higher altitudes without engine de-rating.
Caterpillar also fitted oil-cooled steering clutches and brakes which greatly extended the service life of these components.
Although Caterpillar did not change the serial number prefix of the new improved D7 17A, it did get a new designation of D7D.
These later D7D’s have a distinctive engine note which sets them apart from all other D7’s.
Production of the D7C/D7D had exceeded 19,000 machines when the last one came off the line in 1961.
tomlad
Member
- Location
- nr. preston
Wow thanks for the detailed information sir.
It was ploughing in the furrow
Lads kept telling him , that should be on land ,
His reply to me , and after having attempted to drive it , hes right . One guy driving has far to much to do if on land . Kept me busy just stearing it.
I sincerely apologised after my atemp , he was doing a much better job than i .
Steam tractor i believe originally from South Africa , a foden .
It doesn't have the adjuster, left right on the drawbar , or at least not yet . I think that would have made all the difference presuming you could reach it from the seat .
Not my toy , i may not get to play again i just know its owner.
It was ploughing in the furrow
Lads kept telling him , that should be on land ,
His reply to me , and after having attempted to drive it , hes right . One guy driving has far to much to do if on land . Kept me busy just stearing it.
I sincerely apologised after my atemp , he was doing a much better job than i .
Steam tractor i believe originally from South Africa , a foden .
It doesn't have the adjuster, left right on the drawbar , or at least not yet . I think that would have made all the difference presuming you could reach it from the seat .
Not my toy , i may not get to play again i just know its owner.
Fowler VF
Member
- Location
- Herefordshire
You should try running a crawler on the land with those three 6 furrow Ransomes ploughs hitched one behind the other. (see pictures above) That certainly is far too much to do!! And it quickly teaches you the importance of making sure the hitches are properly aligned.