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This shifting business don't come easy! After driving 6 loops (2 or 3 miles each on curvy backroads), I am struggling to shift this monster...

Call me a nerd, but I built a spreadsheet with with all of the ratios so I can "guestimate" rpm drops to help me shift...

On this last loop, I suceesfully (for the first time) downshifted the main from 5th to 4th...normally, any attempt to downshift either stick results in a complete stop to start agian!

1700 rpm feels and sounds like it time to shift...I wonder if I am not letting wind up high enough...cruising around at 12-1300 seems about right, maybe I am running the engine too slow...

Also, I have not been able to make a two stick shift, end up stopping and starting again!

Those videos make it look sooooooooo easy!

I guess I shouldnt complain...I only have about 20 miles under my belt...I will get it!

Edited by leversole
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Any old Mack motor runs 1500-2100 rpm. You're basically running it too slow to make the shifts. Runn'r up close to the govenor and then shift. Downshifting, let it drop down to about 1500, that way you have RPM to increase enough to catch the lower gear.

REMEMBER..............you have to be going fast enough to UPSHIFT, you can't lag it along like a car as the gears will never get fast enough to mesh for the next faster gear(especially in the main box). My first summer was a real learning curve too as I had no one to teach me!!! No youtube to watch either!!

IMG-20180116-202556-655.jpg

Larry

1959 B61 Liv'n Large......................

Charter member of the "MACK PACK"

 

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Yup! Just like Larry said, take it right up against the governor (2100 RPM) before upshifting. Those motors were made to be run that way, lugging below 1500 was a no no.

Upshifting the compound is easy, waiting for the RPM to drop the correct amount (about 900 RPM) to upshift the main will take practice.

If you get messed up, just think to yourself "what gear and what RPM would be appropriate for the current road speed? Then get your RPM's to that point and shift into the appropriate gear.

If the RPM's are at the point that they would be at if you were already in that gear, it has to and will slide into that gear.

Downshifting will be just the opposite of upshifting, you take it out of gear, raise the RPM to the correct point and shift into the lower gear. I'm not referring to double clutching because I always shift without the clutch.

Once you get the hang of it, it's like a 6th sense.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

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This shifting business don't come easy! After driving 6 loops (2 or 3 miles each on curvy backroads), I am struggling to shift this monster...

Call me a nerd, but I built a spreadsheet with with all of the ratios so I can "guestimate" rpm drops to help me shift...

On this last loop, I suceesfully (for the first time) downshifted the main from 5th to 4th...normally, any attempt to downshift either stick results in a complete stop to start agian!

1700 rpm feels and sounds like it time to shift...I wonder if I am not letting wind up high enough...cruising around at 12-1300 seems about right, maybe I am running the engine too slow...

Also, I have not been able to make a two stick shift, end up stopping and starting again!

Those videos make it look sooooooooo easy!

I guess I shouldnt complain...I only have about 20 miles under my belt...I will get it!

Dont overthink it, finesse that throttle foot, get RPMs right, and all will work better,,,turn loose and feel the force, Luke,,randy

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This shifting business don't come easy! After driving 6 loops (2 or 3 miles each on curvy backroads), I am struggling to shift this monster...

Call me a nerd, but I built a spreadsheet with with all of the ratios so I can "guestimate" rpm drops to help me shift...

On this last loop, I suceesfully (for the first time) downshifted the main from 5th to 4th...normally, any attempt to downshift either stick results in a complete stop to start agian!

1700 rpm feels and sounds like it time to shift...I wonder if I am not letting wind up high enough...cruising around at 12-1300 seems about right, maybe I am running the engine too slow...

Also, I have not been able to make a two stick shift, end up stopping and starting again!

Those videos make it look sooooooooo easy!

I guess I shouldnt complain...I only have about 20 miles under my belt...I will get it!

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This shifting business don't come easy! After driving 6 loops (2 or 3 miles each on curvy backroads), I am struggling to shift this monster...

Call me a nerd, but I built a spreadsheet with with all of the ratios so I can "guestimate" rpm drops to help me shift...

On this last loop, I suceesfully (for the first time) downshifted the main from 5th to 4th...normally, any attempt to downshift either stick results in a complete stop to start agian!

1700 rpm feels and sounds like it time to shift...I wonder if I am not letting wind up high enough...cruising around at 12-1300 seems about right, maybe I am running the engine too slow...

Also, I have not been able to make a two stick shift, end up stopping and starting again!

Those videos make it look sooooooooo easy!

I guess I shouldnt complain...I only have about 20 miles under my belt...I will get it!

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Shifting to the next higher gear, ie, hi 2nd to low 3rd.

As follows:

Relax the pedal holding the Rpm to around 1300, double clutching as you go thru neutral with the main box. Once you drop the main box in gear 3rd, again holding the Rpm at around 1300 take the duplex to the low side raising the RPM to 1600 as you go thru neutral, once again double clutch as you go thru neutral.

The time will come when taking the duplex to low you will gently push the rpm up toward 1600 as you move thru neutral without using the clutch and she will just fall in gear.

Your RPM split will vary slightly depending or gear ratio, tire size and even from gear to gear within the box, but this is in the ball park. If the duplex wants to grind going into the low side of 3rd, let the clutch out with the duplex in neutral, give the pedal a smart alec lick, push the clutch in and drop the duplex in gear.

Don't get in a hurry, the secret is to have the Rpm waiting for the shift at the anticipated rpm. Develop a rhythm. Don't get into the 2 sticks at this time yet. I always thought the most difficult shift to get down was low side of 4th to hi 3rd with one hand.

have fun,

Ray

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Shifting to the next higher gear, ie, hi 2nd to low 3rd.

As follows:

Relax the pedal holding the Rpm to around 1300, double clutching as you go thru neutral with the main box. Once you drop the main box in gear 3rd, again holding the Rpm at around 1300 take the duplex to the low side raising the RPM to 1600 as you go thru neutral, once again double clutch as you go thru neutral.

The time will come when taking the duplex to low you will gently push the rpm up toward 1600 as you move thru neutral without using the clutch and she will just fall in gear.

Your RPM split will vary slightly depending or gear ratio, tire size and even from gear to gear within the box, but this is in the ball park. If the duplex wants to grind going into the low side of 3rd, let the clutch out with the duplex in neutral, give the pedal a smart alec lick, push the clutch in and drop the duplex in gear.

Don't get in a hurry, the secret is to have the Rpm waiting for the shift at the anticipated rpm. Develop a rhythm. Don't get into the 2 sticks at this time yet. I always thought the most difficult shift to get down was low side of 4th to hi 3rd with one hand.

have fun,

Ray

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Ain't no substitute for time in the saddle; the rhythm comes easier than you think. A quad, and a triplex are very easy to drive and shift. I got in the habit of blipping the throttle as I pass the main through the upshift and the aux through the downshift. I tend to mash the throttle up in rpm on the downshifts. To the untrained ear you really can't tell there are two gearsets being changed.

I only have one truck with a duplex and it drives different than the others. I'm not completely familiarized yet, but it's not much different, just a little wider in the gear spacing.

Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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Run the rpm up. remember it goes into gear as the rpm drops. how much weight is on the rear frame does it have a fifth wheel, I have been driving big trucks for 17 years. When I get into my 615 its a different world. you arent goin to get this down by watching videos or down in a couple of days either.dont force it either unless you have unlimited funds. it just goes to show you the quality of drivers in days gone by.

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Partial success! Having the RPMS at 2100 before trying to shift made all the difference in the world. I successfully made the shift from 3rd hi to 4th lo, and 4th hi to 5th lo! Still had to stop a couple of times and start over, downshifting was only successful a few times...

It really shows the skills a trucker had to have hauling freight up and down mountains!

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:SMOKIE-LFT:

I'm going through a similar thing with my 1945 EH's 5 speed w/3 speed Brownie. My truck is actually sorta easy to shift except for the Brownie's shifter being a little stubborn,but it could be worse. The problem I have is trying to shift fast enough to catch it before I roll to a near-stop and have to go back down a gear or two. With no weight behind me and 2 dragging brakes,the truck loses speed too fast. Once I have functional brakes again I can finally hook up to the trailer I have and those factors should help the learning process a lot.

All the time I had my first Harley,I'd been in the habit of blipping the throttle when downshifting so the rpm's would match,making the downshift smoother and letting compression "help" the brakes slow the bike down. When I started riding the Triumph,I had to re-learn my procedure,because doing it the way I did on the Harley,I was usually stopped before the shift was completed.

Speed

:SMOKIE-RT:

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That reminds me,almost forgot about this-

http://www.longroadpro.com/

The "Trucks With 2 Sticks" video here is great, lots of neat old trucks in it. And they break down the shifting part to it's simplest form.

Producer of poorly photo-chopped pictures since 1999.

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That reminds me,almost forgot about this-

http://www.longroadpro.com/

The "Trucks With 2 Sticks" video here is great, lots of neat old trucks in it. And they break down the shifting part to it's simplest form.

But I still don't understand......

Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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OK, i'll break it all down to it's simplest form for you "slower" guys-

push brake button in,let out clutch,hammer down.

Producer of poorly photo-chopped pictures since 1999.

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OK, i'll break it all down to it's simplest form for you "slower" guys-

push brake button in,let out clutch,hammer down.

Must be talking about using a hammer to drive a Pete???? Is it really that bad???

Sounds plausible to me.

Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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  • 3 weeks later...

Know you've probably heard this before,but pratice does make perfect! LOL!.....Herb (HK trucking) has given you some good sound advice,pretty much what i was going to say,just stay with it,pratice when you can,once you get the hang of it,its like riding a bike,just comes naturally!........Mark

Mack Truck literate. Computer illiterate.

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All good advise so far Bobtails are alot harder to shift then a truck with a trailer a truck with a light load on it so try try that if you can. It been a while since I drove a two stick. Put lots of miles on a Quad and Tris

Good luck

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This shifting business don't come easy! After driving 6 loops (2 or 3 miles each on curvy backroads), I am struggling to shift this monster...

Call me a nerd, but I built a spreadsheet with with all of the ratios so I can "guestimate" rpm drops to help me shift...

On this last loop, I suceesfully (for the first time) downshifted the main from 5th to 4th...normally, any attempt to downshift either stick results in a complete stop to start agian!

1700 rpm feels and sounds like it time to shift...I wonder if I am not letting wind up high enough...cruising around at 12-1300 seems about right, maybe I am running the engine too slow...

Also, I have not been able to make a two stick shift, end up stopping and starting again!

Those videos make it look sooooooooo easy!

I guess I shouldnt complain...I only have about 20 miles under my belt...I will get it!

Lots of transmission info on the different models and all the ratios here-

http://www.oldmacksrus.com/trannys.htm

Producer of poorly photo-chopped pictures since 1999.

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