doubleclutchinweasel

Sorry... the "T" is for "twin countershaft". Stepped out for a moment there...

According to the Fuller service manual... 15-speed direct Deep Reduction R - 13.03:1 1 - 12.0:1 2 - 9.42:1 3 - 7.45:1 4 - 5.90:1 5 - 4.78:1 Low Range R - 8.73:1 1 - 8.05:1 2 - 6.30:1 (22%) 3 - 4.99:1 (21%) 4 - 3.95:1 (21%) 5 - 3.20:1 (19%) High Range R - 2.73:1 6 - 2.51:1 (22%) 7 - 1.97:1 (22%) 8 - 1.56:1 (21%) 9 - 1.24:1 (21%) 10 - 1.00:1 (19%) 15-speed overdrive Deep Reduction R - 10.55:1 1 - 9.73:1 2 - 7.62:1 3 - 6.03:1 4 - 4.78:1 5 - 3.87:1 Low Range R - 7.06:1 1 - 6.51:1 2 - 5.10:1 (22%) 3 - 4.07:1 (20%) 4 - 3.20:1 (21%) 5 - 2.59:1 (19%) High Range R - 2.21:1 6 - 2.04:1 (21%) 7 - 1.59:1 (22%) 8 - 1.26:1 (21%) 9 - 1.00:1 (21%) 10 - 0.81:1 (19%) Swapping the drive gears changes the speed of the countershafts. The spacing between gears is determined by the relative number of teeth on the various gear sets.

I've said it before, and I'll say it again; PEOPLE SUCK!!!

At least he falls into the intersection of the sets containing all good things!

Therein lies the problem, doesn't it? The speeds are there, but the torque isn't.

My truck has 4.17 gears, and a direct-in-high trans (1:1). It will cruise at 55-60. 62-63 is about all she wrote. But, 60 isn't too bad. So, let's call this one a 60 mph truck. Depending on the overdrive ratios, of course, a single overdrive (lets call it 0.84:1) will get that 60 up to about 70. A double overdrive (like 0.70:1) will reach about 85...in theory!

Okay! This is one of the funniest things I have ever seen in my life. Somebody put a ton of thought into this one. Those of us of...uhh...a certain age...will get a real kick out of this!

Hey! I changed the scheme from "stainless" to "blue", and they came back! Whodathunkit?

If I log in at a different computer, or use a different browser to log in on this same compuer, they come up "right". So, I must have clicked SOMETHING, but have no freakin' idea what.

My toolbar, with "my content", "my profile", etc..., along with the messenger and notification logos, has moved to the far right-hand side of the screen (see image). How do I put it back across the top? I can't drag it. I can't find any "settings", although that is what I would expect would fix it. Anybody else ever see this? It used to be like the second image...

Excellent point. And, a point well taken. I BELIEVE the filter I took out was for a 750 Luberfiner.

Yep. Very lucky! Fortunately, the engine is running great. Oil pressure holds great. Glad I caught it in time. Probably because the engine does not work very hard...or very much. The "wrong" filter was held down by the aluminum cap. But, the filter did not "seal" properly.

Exactly!!! They really should have called them "12-speeds", shouldn't they?! Mine is the RTF-915. Direct in high gear. Normal shift pattern. If you swap the gearsets in the box to make it an overdrive in high (see pic), every gear (except "direct") gets raised one notch, so the 4th and 5th positions would be reversed. If you didn't like that pattern, Fuller offers a shift plate (basically the top of the trans) which reverses the 4th and 5th shifter fork movement. This would put the pattern back to "normal". There's where all the "x-pattern" and "h-pattern" business comes from. The older boxes, incidentally, should have an "O" in the number to indicate overdrive...like RTO-915. I can't tell you a blasted thing about the newer stuff. My RTF-915 would be Roadranger, Transmission, Front-shift-tower, 950 ft-lbs torque rating, 15 speeds. Elegant system, isn't it? Just wish it was an RTFO-915, with the X-pattern body... Maybe if I ever pull it out, I'll change it!

That is probably your tractor protection valve. It is supposed to close if you lose a hose on the trailer and prevent all the air in the tractor system from escaping. When you pull the red knob, this should close the valve. However, when you apply treadle or trolley valve, air will still be supplied TO the service side of that valve. But, if I remember correctly, it should not pass through (or I could be wrong about that...been a while). If plugging it does the trick, excellent. If not, you could always plug the outlet at the treadle valve which goes to that vavle...or simply cap the line. This would prevent any air from the service brakes from going to the T-P valve. Sounds like you have it in hand,

Two ways that can work. 1. When you pull the yellow, the air is dumped off both circuits, & the red stays up. When you push the yellow down, both circuits are charged, releasing the brakes. 2. When you pull the yellow, air is dumped off the tractor side, & the red pops out automatically, dumping the air off the trailer circuit. To release, you have to push the yellow in and then the red. But, with the red out, there should be no air going to the trailer "emergency" or "pilot" line. However, regardless of pilot pressure, applying the treadle or trolley valves will apply pressue to the trailer "service" or "signal" line. The air from the red goes to one side of the tractor protection valve. Air from the trolley or treadle valve goes to the other side (the one with the quick-release diaphragm). Without a trailer, the red should be out, cutting off the air to the t-p valve. Since I don't pull a trailer with mine, I removed the trailer connection hoses, & plugged the connections with pipe plugs.

So, basically, if you gave a 15-speed, & aren't using "1st" in high range, you are missing 6th gear...

Well, with the new filter in place, & a pan full of Rotella 15W40, the beast is happy. This is hard to describe, but the oil pressure "acts" better. Oh, it still idles hot at 50 psi, & goes down the road at 75. But, on start-up, the pressure comes up "smoother" & stabilizes better. More of a feeling than anything I can explain. And, I think I know why. The filter I took out of the canister was the wrong one! It was a P550750 filter. While physically the same basic size, it does not have the correct gaskets on the ends to seal properly in the can. And, get this, it checks out as a bypass only filter, not the duplex filter it should be. Some $&@! $#&^*#$& put the wrong part in there! No wonder it's happier now! God, I hate people...