What are the secrets to a 15 spd...

Move out of the way old timers...Wasn´t that how you stated a while back...
And Now you ask them for help... Hmmm...
So which way do you want it ?
The secret is practice and watch your Rpm splits...

 

The only 15 spd I ever drove was actually a 10 spd with deep reduction on the low side. You could split the gears on the low side. Some of the drivers around here use them for pulling out of the gravel or sand pit loaded heavy, and some of the log trucks use them.

 

Depends on which type it is most of them were deep reduction 15's which like was said shift like a 10 with the option of splitting the bottom side for real deep reduction and starting real heavy loads off. The others shift like a 13 you split the top side for Overdrive and direct in each upper gear. So it all depends on the one you have in it.

 

15 speed Roadangers are all RANGE type transmissions. LO range (deep reduction), LO & HI range. They shift like a straight 10 speed, you can't
split anything. Some of the gears in deep & lo overlap so they're not a
true 15 speed like a Mack triplex. Stop into a truck dealership and look at
the rack of sales literature, there should be brochures on transmissions
that show ratios, shift patterns etc.

 

Mick's the man!!! I read his post and started to say the same thing and bless your heart....YOU BEAT ME TO IT...Pete make sure and wipe your mouth of with that do rag your so proud of after you eat your words.Don't you owe some "old timers" an apology over in another post????

 

10-4 back at ya....Eaton has vids and a lot of info on their site which saved me a nightmare a time or two.I don't have a link but its fairly easy to find.

 

Let an "old timer" help you out.

A true 15 spd like you have has the deep reduction switch. On the older trucks it was a seperate switch mounted on the dash somewhere. I owned a Brockway (to see what a Brockway is go to the last picture in my photo albums) that had the switch mounted in the floor between the drivers seat and the door.

The deep reduction is used when needing to move heavy loads on soft ground, taking off up steep hills, or any time you need to just creep and not take a chance of burning out a clutch or popping a driveshaft.

When in deep reduction you can start in any of the five lower gears you want, but you can't go any higher than the fifth position without switching to low range.

For example, lets say you started out in 1st gear, deep reduction. Shift on through the gears up to 5th. When you are at the speed or rpm that you need to change to the next gear from 5th deep reduction, reach up and switch the deep reduction out just before shifting while keeping the truck under acceleration.

Instead of going back to the 1st gear position, go to the 4th gear position, as this is the next gear in the ratio sequence. Shift 4th and 5th low range as normal, select the high side from your shifter and go into 6th and shift the rest of the gears as you normally would.

While in deep reduction you do not have to go all the way to 5th to make a progressive shift, or shift on the move. You can shift while moving from any gear but first. To to this you must always shift back one gear after leaving deep reduction. Examples are 1-2-3-move selector, 2-3-4-5, select high range, 6-7, and so on. Always drop back one gear when leaving deep reduction.

If you want to have real fun, drive a 15 speed overdrive with a 9-10 turn around pattern. Your arm will move more directions than a break dancer caught in an electric fence.