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Double clutching?? Unsynchronized transmissions?

E

ef24

New User
I have a Oliver 1655 diesel with a unsynchronized transmission. Had it about 8 years and have never shifted gears - just start out in the gear I want to use, except some what for sixth gear it doesn't bog down when taking off. And even in sixth I've never stalled it. I now read about double clutching and wonder if I should be doing that? Does anyone else do that or am risking damage to the transmission? What was done when this tractor was new? I did learn to drive on a manual transmission truck so I can work a clutch well. Opinions? What do you do?
Thanks, Edward
 
ef24, Do you have over ,under, hydraul shift? I always put the trans in under and shifts much easier. You can speed shift but have to hold your tongue just right!
 
Beg to differ.....most any old tractor can be shifted on the roll, you just have to match engine rpm with the ground speed of the gear you are shifting up or down to.....having said that, it is a bit of a challenge with a 2 cylinder Deere with a hand clutch! Ben.
 
I could throttle shift my JD 3130 up with 600 bu behind it.
Hauled corn with a 1655 as well just used 3, direct/over, 5,direct/over 6, direct
Could not start loads above 3 :)
 
agree, even the W6 mccormick was a very easy shifting tractor on the fly. but those cockshutts like that are a different story.
 
You are absolutely right Ben. Once you get to know your tractor there ain't nothing to it. Even the 2 cylinders, hold your leg against the steering wheel and shift away.
 
Every tractor manual I have looked at etc. has said not to shift on the fly. That is why so many old tractor now have transmission problems. Ya it can be done but you have to get good at it to do so with out maybe causing big problems
 
Double-clutching farm tractors is generally unnecessary and difficult except when shifting into road gear on the fly. In most gears, the tractor will roll to a stop quicker than you can double-clutch, and you are usually dealing with a hand throttle.

I learned to shift non-synchronized transmissions as a teenager while operating my dad's IH 55 Payscrapers. Double-clutching worked well when upshifting, but we usually downshifted without using the clutch at all. You could feel the gears clashing and adjust the engine speed until they synced up.

Even today, when I drive a manual shift tranny, I'll practice shifting without the clutch. It can come in handy. When I was in Egypt many years ago, one morning my driver says "We have a mushkella (problem), clutch broken." I said "Mafeesh mushkella (no problem)", hopped in the driver's seat and away we went.
 
Ed, I would be in 4th rolling along throttled back put it in under while pushing in the clutch and shift to 6th let out the clutch and throttle up.
 
Double-clutching in itself won't always work. You have to time the shifts properly too. It also makes a difference if your trans has actual gears that come in an out of mesh (sliding gear trans), or if you have a constant mesh trans that shifts by lock-collars instead. I have found constant mesh non-snychro transmissions harder to shift on the go and keep from clashing. Like a John Deere 1020. My Ford 641 and IH B-275 both have sliding-gear transmissions and I can shift them both fine, on the go, with no gear clash. First big rig I ever drove was a 1959 Brockway with no synchros and a sliding gear trans. I had to get a lot of practice to shift it without grinding. My boss used to hop in, and shift it with no noise as if it had gear-clutches and synchros.
 
The gear and sliding collar shape in a truck transmission is designed for easier on the go shifting. A tractor’s gears on the other hand are not designed for shifting on the go.
 
Story about the military mindset. Australian, North Africa, WW2 and transport drivers in short supply. It was permisable to snick gears while changing in the then army Ford trucks. An ex-sawmiller on his test could change without snicking while not using the clutch. Got failed for not snicking gears.
 
I have four or five 5-speed non-synchro Farmall and Internationals that you can double clutch and shift on the roll. Speed it up in 4th gear shut throttle down as you clutch and pull into neutral, let out clutch and depress it and slip her in 5th throttle as you let out clutch. Smooth as silk. Skip any of those steps and grind a pound.
 
A lot of people talk about how hard it is to shift the bigger IH transmissions on the go. I'm talking of 56,66,86 series. Maybe it's just because I'm used to the tractors, and I have replaced all of the shifting pieces in them to keep them right, but I don't seem to have a problem with them. I drive them like a pickup with a manual. Depending on what I'm doing, but sometimes you can just take off in 3 HI no problem if a light load is behind you, but if you're pulling a heavy load and starting out heading uphill, I'll start in 1st or 2nd HI, then just throttle it up to speed with the hand throttle, pull it back quick, push the clutch down 1/3 of the way and float it into the next gear, then let the clutch back out and throttle it it back up again. Do that through whatever gear I have to start out in until I get to 4 HI. I don't grind the gears, that drives me nuts. However, if you miss a shift doing it like that, it takes a little longer to feel it out to what gear and throttle you need to be in to get it back in gear.
 
You are correct, I grew up shifting a John Deere B that way. Still driving the same tractor the same way fifty years later, just for fun now through. I have noticed that if I squint my right eye and bite my tongue a little it is exactly the same as a synchronized transmission. It is just one of those things I have been doing and didn't know was wrong until I read here.
 
I shift them on the go all the time. You just have to get used to the character of the particular transmission you're dealing with. The Ford 8 speeds I have... I find shifting up works better by just single clutching and timing it correctly. Downshifts are usually better with double clutching. These are sliding collar, constant mesh transmissions. The biggest difference I find between them and a Road Ranger is that the Ranger will have even ratio splits between each gear wheras most tractor transmissions do not. They're all over the map... and that makes it very difficult to learn how to time the shift..

Rod
 
FWIW I always shift my FE35 as if it is a normal three speed. I figure what little edge I wear off the gears will make them slide together better and also keep from burning and wearing out the clutch. Scoff if you will, but I have never replaced neither the gears nor clutch on a nearly 60 year old tractor. TDF
 
That's the way I shifted my 15 speed behind the 400 hp Cummins Big Cam. Only time you used the clutch was to get rolling in 1st. A little pressure on the shifter, in the right position, let off the throttle, wait, click, back on the throttle and on to the next gear. Really saved wear and tear on the left knee.
 
Some you can some you can't,do it much on most A-C tractors and you'll be doing some expensive trans work.I have an IH here now someone tried shifting on the go now it needs 4th gear.
 

I find this topic a little confusing.
I grew up on tractors shifting gears on the go, that's how my dad taught me to do it, yes there's a art to shifting without grinding gears, it was harder to do on our WD Allis than it was on our Fords.
All of my tractors but one are 60's to early 70's models, only one has had the trans apart for repair and that was because of a bearing failure.
For those that never shift on the go, when pulling a load up a hill or you hit a soft spot in a field and the engine chokes down, do you stop, shift the a lower gear and than try the take off again, do you slip the clutch taking off in road gear until the tractor gets moving.

If I had slipped the clutch trying to take off in too high of gear when I was young dad would had taken a leather strap to my back side.
Someone explain to me how you take off down a road with a load behind you and use road gear without ever shifting on the go.
I like the old Allis tractors but it's a well known fact that they had weak transmissions.

The one tractor I have with a synchro trans is the hardest one to shift, doesn't grind gears, it just shifts hard and slow, good thing it has dual power for quick shifting when needed.
 
I never could get the hang of the older Farmalls but the Fords I drove for one farmer were so wore out you'd have to start in low just to pull a throw rack with bales. Got pretty good at shifting them Ford four digit models. The IH 06 series I could shift on the fly but you have to have it just perfect.
 

Rules are simple, tractor must be rolling and continue to roll when shifting (like on road pulling a wagon, not in field pulling a harrow)

As long as you have a foot clutch and foot throttle you are usually good.

If you aren't grinding gears or ramming stuff then you aren't hurting anything.
 
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