15 speed and 4 speed auxiliary

It spun over and fired up on the first crank. 350 Cummins I think the guy said ? 76 year if I remember correctly... the one bad thing was there was so much slop in the gears, u could put it in gear then shift to 4 other ones without it ever coming out of the original gear

 

The old boy that tought me how to drive when I was a kid had a 13 and a 4 in his log truck

 

Ok, you guys are beyond me in your knowledge. My 379 has a 15 against the dash, with 3:55 rears. What would a 4 speed auxiliary do in this truck?

 

Yepper. Drove a few long loggers with that set up +2 spd rear ends

 

Is he is a part time sniper for the FBI that gets calls for the Federal Marshalls too?

 

Quite often the Aux-box is as much for the mechanical drive of the main winch as it is for low-low speed work on the lease and the overdrive for moving empty between leases.

 

Put a RTLO18918B in it. It will be 3 times cheaper and get you a lower low hole, plenty of high hole and a 13 percent difference between each gear. It will put you at 1500 or so with tall rubber between 70 and 75 mph.


A C ratio 1241 would make that thing flat move but it will make heat in the big hole. It goes to whining you better get it back in direct pretty quick or it’s gonna be sad times. They can be a royal ##### to put in and get shimmed right. If you miss that part you’ll never be happy. The spread on the splits will be really odd too. Not to mention the 18 will most likely be all around stronger. Now I’m not trying to discourage you just giving an honest opinion now that I see your wanting to add not figure one out that’s already set up that way.

If your looking for a really deep set for lift when extremely heavy or soft ground then the 4 speed starts making a lot more sense.

 

4 speed progressive, double under, under, direct, and over. Advantages will be starting loads when you're heavy in soft conditions, being able to split the 15 when the gap is a little long to grab another gear, and of course an abundance of overdrive.

You will have overlap and won't be able to use it like a 5 and 4. Like @wore out said you would probably have a lot of gear noise when both in over. With different overdrive ratios between the two you would be able to swap the 15 in direct and the brownie in over and visa versa and wind up with slightly different road speed. Also, suppose you are in over in the 15 and direct in the brownie and you pull a hill where you can't quite hold it, but don't need a full gear to make it to the top, splitting the brownie to under may be less of of a drop and get you to the top.

Disadvantages are weight, another driveline (unless there is a married application - not sure that exists), increased potential for vibration and noise, and you will need a big screwdriver or bar to un-stick the linkage if you have a bit of wear and round the corner of the shift pattern.

That's all the input that I have.

 

With the existing 15, 3:55’s, y’all 24’s and B model, it’s just starting to flirt with 1550rpms. I’ll leave probably leave this truck alone, as I’ve really taken up with this 15. In L2 it’ll spread rock beautifully.

 

I sure miss my 15. Most forgiving transmission I ever ran. With 3.36’s and tall rubber it was the cats ### for what we do.