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Clutch, I don't need no stinkin clutch!

P15-D24

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As an owner of a B1 truck with an original 4 speed crash box (aka non syncro tranny with compound low) one story you hear is you can shift without using the clutch. Having learned to double clutch to avoid the "grind them till you find them" syndrome of shifting I have to say I was always intrigued by the myth of clutchless shifting. For our owners who always lived in the world of fully synchronized transmissions, double clutching is the technique used to shift a transmissions with "straight cut gears' or no synchronizers. Internally the transmission is pretty simple and very reliable in service.

To double clutch you use the clutch normally to get rolling and when you are ready to to shift your depress and release the clutch once to take it out one gear and a second time to go into another the next gear. The process basically slows down the shift so the gear speeds match and allow them to slide into the next gear. Downshifting is similar except you have to remember to bring up the engine revs as you go into the lower gear.

But what about clutchless shifts? Well, as professional OTR drivers know it is not a myth but a useful technique to drive your truck with less wear and tear on the clutch. Success is all about getting the engine speed right and feeling the gears as you slide them in the gearbox. Again use the clutch normally to get rolling. As you near the shift point lift off the gas slightly and slide the shifter into the gate for the next gear. As the speeds match the shift will smoothly drop into the next gear with no grinding and no clutch needed! Don't be frustrated if the first few times you miss and grind the gears. With a little practice you will be able to tell with engine speed and feeling it in the shift lever when it is time to shift. Downshifting is also possible but requires a little more finesse with engine speed and shift lever. Remember since your are going down in gears you need to raise engine rpm to match the the gear when you downshift. So instead of a slight lift off on the throttle you need to give it a little bump up. Again with the gear speed and engine speed match you can fell it in the gearshift lever as it will easily slide into gear without a grind.

And what about the compound low (AKA, granny gear)? It's function is to help you get moving when you have a big load on board. A while back I had half a yard of sand loaded in the bed. When I started to pull out of the loading area in first it was immediately evident I would have to slip the clutch quite a bit to get rolling. Dropping into compound low we just pulled out like a normal start, just slower. Once we got past the the initial start up resistance from a dead stop it was easy to drive.

Have any of you mastered the art of clutchless shifts?


jyinger likes this
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I  drove 400 miles home in a VW van that snapped the clutch cable. I had it down - smooth shifts up and down, and luckily no full stops until I got pulled over for a random breath test. The policeman looked at me strange when I turned of the engine. I waited until he wandered off to the next car, threw it in 2nd and hit the starter. A couple of bunny hops and away praying he didn't come after me.

 

And I'd like to thank my dad for teaching me double declutching and clutchless shifting when teaching me to drive in his 45 year old (at the time)1929 Plymouth.

 

Cheers

 

Rick

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I've done clutchless shifting for years, but mostly with newer syncro-mesh transmissions. This summer I worked on my clutchless shifts in my B2C with a crash box 4 speed. I started getting better, but I find that since my truck has Fluid Drive, which essentially acts like a big, heavy flywheel, the timing is slightly different that I would normally expect. Once I figured out the timing I could shift just fine. And since I do have FD, all I had to do was get it down to 3rd or 2nd and stop with the brake. Then I could let off the brake and drive away and continue shifting without ever using the clutch. It was fun.

 

Merle

PatS.... likes this

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I used to to this all the time with a 10 wheeled GMC Astro tractor with a  10 speed road ranger / 318 Detroit, and a Brockway with a 13 spd rr and 318 dd.  It's easy to do with a non synchronized transmission.  If you do it correctly you can accellerate smoothly w/o so much as nicking a gear.  Do it incorrectly and you can eat ujoints and transmissions in a very short time.

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I learned how to do this in my dad's 48 Plymouth Business coupe.  I am at a point now I only use the clutch from a stop in anything I drive, wether its the Kenworth at work, my Wrangler, my Neon, or my Honda ATCs.

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I rarely use the clutch (upshift or down) on any of my personal vehicles once I'm moving, unless I'm in a vehicle that I'm not familiar with I'll use the clutch until I get used to the shift points and the rpm drop between gears. I will use the clutch if I'm in a hurry though, like when I take the '46 down the dragstrip or a quick blast down a country road.

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After driving a Rig for 40 years, had ten gears that I went though nothing to it for a pro.

I once lost had the clutch arm on a KW Tractor pulling doubles that's two trailers, we were at Goodland Ks and I drove back to KC without a clutch starting the truck in low, even going across the scale I simply rolled on the scale and when told to pull off again I just started it and drove on in to the terminal.

I have rode Motorcycles and didn't use the clutch only stating and stopping.

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I learned how to shift without a clutch just for the fun of it. But, just like Ricky Luke, when my own VW bus clutch cable broke I was able to drive it home. What I felt was just a stupid boyish "trick" actually saved me some money and grief. I guess I only get to pull off the BIG SAVE once in a life time because I have not had a similar clutch failure on other cars.

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I've been doing it since I learned to drive around 6 years old! Dad and GrandDad owned a truck repair shop and taught me how to drive in '54 Dodge pickup and moved up to an older White conventional before they let me try Dads' '57 Mack B57!  

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I've found it pretty easy to go through the gears, up and down, on the old foot clutch Harleys without using the clutch.

ken

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The Army taught me how to drive in a 4 tonner and as we still had vehicles in service that didn't have syncro in the lower gears I learnt to drive double de clutching. Unfortunately you can't drive a fluid drive like that... Not really tried clutch less except once when my Range Rover lost it's clutch whilst out looking at a classic Mercedes 450 SEL 6.9, that was an interesting drive home.

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