***Summary of Responses to original question***
The vehicle should be in gear while moving to maintain control of the vehicle. Avoid coasting (in neutral) even when deaccelerating.
Basic technique:
To accelerate:
Use first to get moving and quickly get to second from there. Shift second, third, fourth, generally when RPM is somewhere around 20 RPM, 5th at cruising maintaining the 20 RPM as general target (RPM gauge generally pointing up but not exceeding the warning sticker).
To deaccelerate:
Downshift, using double clutch if needed (clutch to take out of gear to neutral, release clutch, clutch again to get to next lowest gear). When going into next lowest gear gently tap the accelerator (blip) to match engine speed to transmission to avoid grinding. Avoid exceeding RPM warning sticker of around 25RPM. Timing clutch, blip, and shift takes practice. When downshifting, if your truck lurches/lugs, this means you are moving too fast for the gear you are downshifting to, use brakes to slow to a speed that is matching for the gear you are trying to use.
RPM ranges can be found in Untitled (jatonkam35s.com) PS magazine's article on the Multifuel Operator on page 13.
From TM 9-2320-209-10-1 page 4-54:
Trucks covered in this manual should be operated within the following rpm limits, as shown on tachometer (l):
(a) 1200. Lowest engine rpm when operating under load.
(b) 1400-1800. Engine rpm recommended for downshifting.
(c) 1400-2200. Engine rpm recommended for cruising.
(d) 2600. Highest engine rpm recommended when pulling a very heavy load and when going up a very steep hill
Heavily loaded vehicle or steep (uphill) grade:
in case you are very heavy and/or the road is very steep (Upshifting) - starting out with the transfer case in LOW (down to the floor), getting going in 1 (or2), shifting 3-4-5, then transfer case to HIGH and shifting 4-5. In total, that gives you 7 gears when you need closer steps between the shifts.
Avoid downshifting the same way; the transfer case seems happy in the upshift LOW to HIGH but it is not synchronized and may cause additional wear in downshift situations.
Floating gears:
An advanced technique that is not universally recommended, but possible. Review responses in this thread to determine if you wish to try this. When shifting, without depressing the clutch move the gear from the gear you are in to the gear you wish to go to. To do this, you will have to match the engine RPM to the drivetrain RPM with throttle. If you get this right you can pop the transmission into the desired gear without the clutch. Doing this will take a great deal of familiarity with what speed range/gear combinations your truck likes, and good coordination.
" Being a rebuilder of heavy truck transmissions, I can honestly say "floating the gears" is the worst thing you can do for the longevity of the transmission. " - Rustystud - Read his post page two for deeper explanation and subsequent debate on floating gears.
This summary is for someone looking for this information so they can find it quickly. Ill edit this summary based on responses.
***Original Question***
I am familiar with manual shifting in general, but most certainly not with a vehicle of this scale. If this is answered somewhere, please point me in that direction as I wasn't able to find this information using the search terms I used. The information I found focused on the unusual shift pattern and what gears are or not synchronized.
I was able to get my truck home after a 12 hour trip and am quite happy with it. I managed to do this without being too hard on the transmission but as I was driving I was wondering what methods experienced duce drivers use in shifting that I just wouldn't know about. Based on the information I did get:
Use first to get moving and quickly get to second from there (this takes getting used to, but not bad)
second, third, fourth, generally when RPM is somewhere around 20 RPM, 5th at cruising maintaining the 20 RPM as general target (RPM gauge generally pointing up but not exceeding the warning sticker).
If the above is incorrect, please do correct me.
I assume downshifting is desirable to save brakes? I tried this but my technique was poor so I just went to neutral and used brakes to stop for the time being.
Naturally, this will take some practice and windshield time, but if experienced drivers could share good shifting habits for both moving up through gears and slowing/stopping I would appreciate it.
The vehicle should be in gear while moving to maintain control of the vehicle. Avoid coasting (in neutral) even when deaccelerating.
Basic technique:
To accelerate:
Use first to get moving and quickly get to second from there. Shift second, third, fourth, generally when RPM is somewhere around 20 RPM, 5th at cruising maintaining the 20 RPM as general target (RPM gauge generally pointing up but not exceeding the warning sticker).
To deaccelerate:
Downshift, using double clutch if needed (clutch to take out of gear to neutral, release clutch, clutch again to get to next lowest gear). When going into next lowest gear gently tap the accelerator (blip) to match engine speed to transmission to avoid grinding. Avoid exceeding RPM warning sticker of around 25RPM. Timing clutch, blip, and shift takes practice. When downshifting, if your truck lurches/lugs, this means you are moving too fast for the gear you are downshifting to, use brakes to slow to a speed that is matching for the gear you are trying to use.
RPM ranges can be found in Untitled (jatonkam35s.com) PS magazine's article on the Multifuel Operator on page 13.
From TM 9-2320-209-10-1 page 4-54:
Trucks covered in this manual should be operated within the following rpm limits, as shown on tachometer (l):
(a) 1200. Lowest engine rpm when operating under load.
(b) 1400-1800. Engine rpm recommended for downshifting.
(c) 1400-2200. Engine rpm recommended for cruising.
(d) 2600. Highest engine rpm recommended when pulling a very heavy load and when going up a very steep hill
Heavily loaded vehicle or steep (uphill) grade:
in case you are very heavy and/or the road is very steep (Upshifting) - starting out with the transfer case in LOW (down to the floor), getting going in 1 (or2), shifting 3-4-5, then transfer case to HIGH and shifting 4-5. In total, that gives you 7 gears when you need closer steps between the shifts.
Avoid downshifting the same way; the transfer case seems happy in the upshift LOW to HIGH but it is not synchronized and may cause additional wear in downshift situations.
Floating gears:
An advanced technique that is not universally recommended, but possible. Review responses in this thread to determine if you wish to try this. When shifting, without depressing the clutch move the gear from the gear you are in to the gear you wish to go to. To do this, you will have to match the engine RPM to the drivetrain RPM with throttle. If you get this right you can pop the transmission into the desired gear without the clutch. Doing this will take a great deal of familiarity with what speed range/gear combinations your truck likes, and good coordination.
" Being a rebuilder of heavy truck transmissions, I can honestly say "floating the gears" is the worst thing you can do for the longevity of the transmission. " - Rustystud - Read his post page two for deeper explanation and subsequent debate on floating gears.
This summary is for someone looking for this information so they can find it quickly. Ill edit this summary based on responses.
***Original Question***
I am familiar with manual shifting in general, but most certainly not with a vehicle of this scale. If this is answered somewhere, please point me in that direction as I wasn't able to find this information using the search terms I used. The information I found focused on the unusual shift pattern and what gears are or not synchronized.
I was able to get my truck home after a 12 hour trip and am quite happy with it. I managed to do this without being too hard on the transmission but as I was driving I was wondering what methods experienced duce drivers use in shifting that I just wouldn't know about. Based on the information I did get:
Use first to get moving and quickly get to second from there (this takes getting used to, but not bad)
second, third, fourth, generally when RPM is somewhere around 20 RPM, 5th at cruising maintaining the 20 RPM as general target (RPM gauge generally pointing up but not exceeding the warning sticker).
If the above is incorrect, please do correct me.
I assume downshifting is desirable to save brakes? I tried this but my technique was poor so I just went to neutral and used brakes to stop for the time being.
Naturally, this will take some practice and windshield time, but if experienced drivers could share good shifting habits for both moving up through gears and slowing/stopping I would appreciate it.
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