Better Mileage

[siris]

cool. did not know about the switch delaying the shift. i thought it prevented all together. as far as the kickdown cable, it snapped right off at the throttle arm. its been like that for 10000 miles.

[siris]

I've always had a problem with od kicking in late since I've owned the truck. With the kickdown cable intact it would still run to 65 mph before shifting into 4th, then downshift to 3rd with any more than 1/4 throttle. It shifts like this, 1-2: 15mph 2-3: 45mph (however if I manually shift the gearshift into 2nd then slide it back into drive it will shift at 35mph) 3-4: 65mph and it comes back out of 4th at 45mph. Does anyone know if the factory modified the shift points in the power rams? I would think it would shift to 4th at about 45, not kick out of 4th at 45. On a side note I bypassed the temp sensor to no prevail. Does the KM148 have a front pump for transmission fluid? If so does anyone think it could be the pump not producing enough line pressure to properly shift gears? I've changed transmission fluid and cleaned the screen mesh with no changes in shift behavior.

[pennyman1]

Its the kickdown cable out of adjustment- it controls the valve body that diverts fluid flow in the tranny to determine shift points. It is a tough adjustment to get right- with a good cable leave a slight amount of slack in it, drive it, push the pedal down slowly to see where it downshifts after it warms up and your in the highest gear it gets to at 45. It should downshift at about 2/3 pedal travel- if earlier, put in more slack, if later, take slack out. Once it is set right, OD should occur at 45.

[77amc]

You say 3/4 trottle?? And you still want better mileage lol??

Anyhow, your linkage might be binding to open up the secondary.
That's easy enough to check out while it's not running. Just pull the aircleaner and slowly have a "beutiful" assistant push down on the gas peddle and see if it's even adjusted correctly, then see if it is opening the secondary fully.

From what I remember, They only need about 2 1/2-3psi to run.
Check out that little window (that you can see the jets) and see if it's flooding at all.

E

[siris]

update, secondary vac diaphram was shot. fixed, trans kickdown cable fixed. still no od until 65. but in 4 low it hits od at 35. cant figure it out.

[wrngwae]

what bout if you let off than roll into again will it go into overdrive?

[85TDW50]

Allisons are in fullsize ram diesel trucks

Never seen an Allison Transmission in any of the Ram 2500 / Ram 3500 Cummins equipped trucks. Might be possible in some of the heavier Cab & Chassis/Incomplete Vehicle duty trucks like Dumptrucks, Towtrucks/Wreckers, Rollbacks, Flatbeds, ect But not in any of the Complete Vehicle/"Off the Lot" models that i've seen

The Transmissions i have seen and or heard of are :

NV4500
NV5600
NV6500
A727
A518
A618

The A518 & 618 are Overdrive Torqueflite Automatics that were based off of the Torqueflite 727 3-Speed Automatic

[raidinator]

Recently Alison transmitions are in the current GMC trucks, however the name's fame comes from the fact that they manufacture the transmitions for the current M1A1 tanks. I believe that if gen 1 montys and raiders had Alisons it would be a more well know fact. thats just my thought anyway i haven't climbed under the car or anything for this one.

Speaking more directly to the title of your question efficiency comes from the the engine's ability to to recover more energy from the fuel input. so making that engine's operations easier will increase efficiency. I'm building an engine now, for efficiency i am keeping the stock mikuni, adding pace setter headers with an extremely free flowing exhaust. I have smoothed the headers, head, intake. I also added a K&N air filter. My theory is that if it takes less effort to pull in and push out gases the engine will be more efficient. I also bought some fancy spark plugs and an msd coil being put through 8mm wires. my theory there is that there will be more complete combustion. hence less fuel escapes out the exhaust. the whole thing cost like 300 bucks so i think i'm going to get that back in MPGs. so i vote you try that also an air fuel ratio guage, it should help things out in the tuning department

By the way i built an engine before this and ran it as aq work truck and being hte lead footed buffoon that i am i got 21 mpg mixed city and highway

good luck buddy

[pennyman1]

pretty good combo- the only thing i'd change is the header. I'd use a doug thorly tri-y header, its designed for low to mid-range torque and power with peak effiency around 3500rpm. The Pacesetter is mainly for high-end power. I've run both- doug thorly is definately better.

[LethalEthan]

^ what he said if you can even find a thorley anymore. Not to mention pacesetters build quality.