Why Does a D4 7U have 5 Gears?

First Cat I ever owned was a D4-7U ,43xxx series and it had 4 speed forward 2 reverse box and I recall it was an optional extra , 4th gear was fairly quick and I never Drove it at full revs unless pushed for Time .
Going Corryong next Month ? at least 3 of us are Planning on Coming down from Qld and give Wombat some support . for Proposed Chapter . LJ

yeah maybe - depends on the missus and the remaining at home teenager's demands/plans for that weekend though. But I would love to be there and check out all the Cats.......

Hi, Inter674.
I can't say about the 4G or 7J series D4's but all the later D4's that I have run had five forward speeds and would quite happily travel in 5th - - - at least until you wanted to pull a bogged loaded truck uphill. LOL. Mind you, as Lance said, full throttle in the long cog was only if you were in a serious hurry - like trying to outrun a bushfire - - - - or if you REALLY wanted to pay for a new set of track chains in the near future.

Way back in my mis-spent youth, I worked on a wheat and sheep farm in W.A. where there was a 2T series D4, 36 hp, and I used to pull 2 x 14-disc Sundercut plows in tandem in 4th quite a bit, down to 3rd when the going got a bit heavy. I could pull them lifted out of the ground in 5th put not in the ground. LOL.

Having said that though, 2 x 18disc Chamberlain plows in tandem slowed it down a bit. How-wevver, I suspect that the two 'slightly' different tandem set-ups might have had something to do with that too. The 2 x Sundercuts were hooked together via a drawbar welded to the back of the front one and they pulled pretty light. The 2 x Chamberlains were coupled up with a bridle and beam set-up and seemed to pull somewhat heavier than I thought the 8 extra discs ought to have pulled. But what would I have known at 19 years old?

Just my 0.02.

It's quite common to see the 4th and 5th gear shifter plate blocked out (welded) to keep cowboys in check.

It's quite common to see the 4th and 5th gear shifter plate blocked out (welded) to keep cowboys in check.

My D2 5U13247 has a 5 speed box in it. I very rarely use anything higher then 3rd, not have a large enough area cleared to get it much higher.

Kevin

Hi Team,
be aware that by the Rack Charts the early U tractors were rated at 1400 Rpm Full Load Speed and later ones were 1600 Rpm F.L.Speed
Correspondingly the Horse Power went from 51 to 58 and then 60.5 by the end of my Chart range.
This then took advertised travel speeds (that I found in Sales [1947] and Parts literature[3-1952]) in MPH from / to,
1st 1.7 to 1.9
2nd 2.4 to 2.7
3rd 3.0 to 3.4
4th 3.7 to 4.2
5th 5.4 to 6.1
Rev 1.9 to 2.2
Cheers,
Eddie B.

Great info guys

I will see if I can track the speed using the GPS and compare it to the spec sheet.

But currently it is too fast for us on steep ground where it can get a bit hairy at times😊

Also, I agree that the governor probably needs looking at as it does not seem to want to hunker down and puff smoke readily - but the engine is reconditioned - new rings, bearings etc.

Video of the D4 in 1st gear, but not at full throttle - perhaps at 3/4 throttle only.

http://s71.photobucket.com/user/Inter674/media/D4Vid.mp4.html

As far as puffing smoke under load, my current D4 7U won't either, barely a bit of a slight (almost unseen) haze under heavy load. The only time there's even a hint of a puff of black smoke is if I open the throttle all the way suddenly under load. Most work I do is done at half throttle or maybe a bit above that.

While it will clatter along happily in 5th on snow, I rarely use that gear and only at about half or less throttle.