Thats the way I do it in big rigs as well. I can do it in light vehicles with manuals but prefer not to.

 

Edwin, your brother is wrong. That's the worst thing you can do to the synchros. It puts a tremendous amount of load on them. I hope you haven't been following his advice.

Real truck transmissions (ones with more than 6 gears) are not synchronized, they use dog rings instead. They will not go into gear unless you get the RPM matched pretty closely, where a synchronized trans will go into gear (at the expense of the synchros) even if you get it wrong. Your brother's method is even bad for non-synchro transmissions, pulling on the shifter and then stabbing the gas will make it shift, but the shock load on the whole driveline is massive. I would bet he's not an O-O.

The proper way to make a clutchless downshift with a real truck trans is to match the revs first, then gently put the trans in the desired gear. If done right, it is smooth and silent. I'll be the first to admit mine aren't all that way, but most of them are.

 

I don't fully agree, it doesn't hurt a thing if your good, my brother and I both drove OTR for years and can shift it in smoother than with the clutch. And I also have a GM truck(NV4500) with 428k on it that has never needed a new syncro driving it that way too. You don't apply the juice until your gears have matched speed, and then are completely engaged, just learn on someone elses truck if you can.

 

Thats the way mine are(most of em)

 

I have to partly agree with Wanna on this. If you're good you can do it but I'm not that good and I'm lazy. It might save wear on the clutch but I figure a clutch plate is cheaper to replace than synchros. Besides, the clutch was INTENDED to take the slippage and wear while the synchros were intended to synchronize the gears so they wouldn't grind when shifting.

I have driven a motorcycle with a broken clutch cable and while it's possible it isn't fun. It jerks something awful when the gears are changed so I can imagine that it's much harder on the gears in a heavy truck.

NO. I don't do this. It didn't make sense to me to begin with so I don't do it.

Edwin

 

Most of the big rig ERFs in the UK when fitted with the 14 litre Cummins had a Eaton 12 speed twin splitter gearbox fitted. Once on the move you never needed the clutch,just ease the gogo peddle and change up or down.The advert for the Eaton used to read,never use the clutch between Edinburgh and London.
The Eaton will not now pass drive by noise tests so went out of production about 4 years ago, it was bullet proof.Some of the double drive low loader rigs still use the Eaton Fuller 13 speed another constant mesh gearbox thats bullet proof.

I`ve tried double declutching my 2wd auto but can`t find the clutch peddle

 

I blip the throttle on downshifts if I have the room - hardly have to touch the fat pedal; if in a hurry to stop I just clutch into neutral and heat up the rotors.

 

I never was able to get my NV5600 to shift worth a darn without the clutch. My dad used to have some large F-series Fords in the 70s that shifted better without the clutch, but I couldn't repeat that sort of thing with my 2002.

Tad

 

3-4 shift is a breeze on an 02 eth. Haven't had much luck with the others. Kinda makes me want to put in an eaton fuller

 

i can downshift my nv5600 no problem with no clutch, but upshifting is not an easy thing to do..

 

So what do you guys think of the way I shift and am I hurting anything? I always shift in this nature other than gettin' OL'gray moving. I come out of gear with correct rpm's, depress clutch, blip throttle if down shifting-let rpms drop if up shifting, plug it in gear, release clutch and roll on.

T398

 

That's how I think it should be done.

Trannies with synchros: use clutch, and help them a little.

Trannies without synchros: Do what you want, they aren't going into gear until the revs match anyway.

I never use the clutch in the Western Star, once it's rolling.

Transmissions are very efficient lathes by the way. By using Edwin's brother's method, one could eliminate all that annoying gear drag in a short time!

 

I agree with Wanna, its bad to shift a syncho tranny without a clutch. It puts a lot of stress on your synchros, unless you do it right. By pressing the shifter towards the next gear untill it pops in is bad, thats what tears up synchros, if you hold it in nuetral untill just the right moment and then shift you shouldnt hurt anything. But holding it "against" the next gear till it pops in is terrible for synchros.