dozer transmissions

[ofarmer]

In the 85 hp range, which would be the best transimission, a hydrastatic or power shirt? If power shift, direct drive or torque converter? Any make dozer that should definitely be avoided?

 

[NCWayne]

They are all good choices but ultimately the one you choose depends largely on what type off work your wanting to do. One thing to do first is to understand how each works. Direct drive is just what the name implys, it"s all geared, sort of like a manual transmission. The "powershift" is more along the lines of an automatic and uses hydraulic force to engage various clutch packs for the different gears. Typically they have a torque converter driving them. The hydrostatic is all hydraulic driven. In other words a vaqrfiable displacement hydraulic pump sends flow to a piston motor which in turn provides power to the tracks.

That said if your planning to do alot of really heavy pushing or pulling (say a bowl scraper, etc) then the best choice would be a direct drive, and the second choice would be a "powershift". Typically you see alot of powershifts doing this work now since there are very few (if any) direct drive machines even being made nowdays. The main thing is with the powershift being hydraulic HEAVY pushing creats alot of heat that eventually wears out the internal components of the transmission wher direct drive is all gear driven so no real heat is created.

If your doing average type pushing then either the powershift or the hydrostatic are good choices. Usually the hydrostatic provides more maneuverability (can typically turn in it"s on length) so if your working in tight quarters then the hydrostatic is the way to go. Too hydrostaatic is usually faster then powershift if for no other reason then with a powershift you have to shift from fwd to rev where as with hydrostatic changing from fwd to rev is "seamless" since all your doing is reversing the flow to the motors.

Beyond that, like I said, all three designs are good choices it just depends on what your doing as to which one you choose. Hope this helps.

 

[Billy NY]

Preference for heavy drawbar work is direct drive/oilbath clutch which caterpillar built a good reputation on, even while the powershift was developed. The oil bath clutch was a big improvement over dry, the latter requiring more adjustment, maintenance, depending on the operator, conditions, both still had a reliable reputation, tractors with direct drive and oil clutch provided longer service with the improved clutch arrangement. I think you also need to consider individual tractors and how they were taken care of, when looking at older ones, even the best design, under abuse will or can be problematic.

 

[RodinNS]

Best in what respect? I think that's a more relevant question...
IT may be that direct drive or even power shift will last longer that hydrostatic... and I think that's a qualified mabey... but the hydro will be more functional in just about every way.
When you take a direct drive or powershift machine, get the blade full and then try to turn you'll soon find out why hydro has a distinct advantage. You can't steer. They can....

Cat's larger amchines get around this with differential steering. Others had two speed or 3 speed drives on each side that could be kicked up or down... and the older cases had split drivelines for each side. You could make the tracks counter rotate and spin on a dime.

Clutch and brake steering is not particularly desirable more most things.... it's just that it's been around a long time.
I'd go for a hydro if I was buying a new one.

Rod

 

[ofarmer]

Thank you for the replies. I should have qualified my questions. I've never owned a dozer, looking to buy a used one, and don't know which salesman to believe. I've always thought you get what you pay for, but some times you don't!

We won't be doing any heavy pulling, just mainly grading lanes, ditches, roadways, logging roads, etc., along with leveling off gravel and dirt for different projects. Definitely want a 6 way blade, but not sure about transmissions or which machines to stay away from.

Have narrowed my search down to JD 650G/550G, Cat D4C, Dresser TD8H, or a Case 850D. Not trying to start a color war, but would appreciate the good, the bad, and the ugly of these units if anyone has time to respond.

Thank you.

 

[Bob Bancroft]

Sorry I can't address any of those models. I have a Fiat/Allis FD5 which has turned out to be a great machine for me. It is 3 speed full power shift/ torque converter drive. (standard old clutch and brake steering) I really appreciate the torque converter. I can ease up to something, and then let it rip, without slamming things. Prior to this I had only run the older JD 350/450 w/power shift/direction reverser. Of course hydrostatic would give you the same capability, plus the increased maneuverability mentioned below.

 

[scot in pa]

The "direct drive", if you are talking about it on the Dresser, is a powershift without the torque converter. The torque converter setup is the better set-up, as you can stall the tracks with the decelerator when you are working close to something, like a wall, or a cliff, while the clutches stay engaged, where in the direct drive the clutches do all the slipping when you stop or shift. The T/C acts as a cushion. It is like an automatic transmission, but it stays in the gear you select, instead of up- and down- shifting itself. The direct drive is a lower-cost option, and won't give you as much pulling or pushing power.

Our TD8-G (T/C powershift) has over 8500 hours on the clock, and we bought it after my grandfather leased it for three years, and he had a habit, even after we bought it, of running it with the master off so the hours wouldn't show on the meter. So after 9000 hours or more, pulling a pan, pushing dirt, moving drilling rigs, packing silage, and wearing a hole in the blade, it is still going, and other than a cam (the original broke, increasing the idle speed and putting in H series mounts fixed that), the engine has never been opened past injectors(thank you, EPA, for ultra low sulfur fuel). The transmission has never been opened, and the only maintainance it has taken is fluid and filter changes. Use Hy-tran or a good name brand equivalent oil and it will live a long long time.

Ours is not the only Dresser in our area to live this long. Between 9 and 10 thousand hours seems to be the point to give up on them, for guys inclined to run them into a grave.

I hope once Komatsu spins Dresser off, they will pull the dealership from the clowns that have it locally here, and give it back to the old IH dealer, and then get their prices back in line.

Wayne, you are actually describing a gear drive, and I don't think anyone builds them anymore, the powershift is such a superior set-up. Not to be a donkey here, but what difference is there in a drawbar load and a blade load?

The only other dozers I have run were a 450 deere, I can't really give an opinion on that as I didn't do a whole lot with it. And a 650 wide-track. I didn't like it, as there was too much blade and power for the weight. It was great for grading but for doing any real pushing it was worthless.

Don't know what series the Deere's were.