Splitting the 13-Speed

It's a minor point of clarification, but.....are you under the impression that with the splitter button forward is OD and aft is direct?

 

I didn't know it was common practice to split downshifts. Never driven a 13 or 18 but have wanted to try one.

 

Most (all?) 13's are a double overdrive. Only the top 2 gears are OD I believe.

 

There are some single OD 13's but most are double OD

I have driven a 13 since Jan and I still grind a little every now and than, believe me, I wish I was perfect but, I am not. What works best for me is to stay on the fuel, move splitter forward, than left off the pedal, it goes right in but, you have to be in the right RPM's for the load you have. Going down, I don't split...if I am in 13th I move the splitter back and use the clutch to move it into 12th, than just don't split from there on down.

 

This was true with the old RTO-1XX13, but the RTLO boxes are underdrive button back, and direct, button forward. So...

The RTLO trannys have 2 OD gears, but they aren't double overs in the way of old school RTOO and multiple box setups, as only the main box is an overdrive in high gear, the aux is in direct. This setup results in one less gearset in the power path in high gear, reducing parasitic losses within the tranny. The old school double overs had three overdrive ratios: 11th (Main direct, aux OD), 12th (Main OD, aux direct), and 13th (Main OD, Aux OD.) That pattern was the same with a set of boxes, as well, though the numbering would differ depending on which setup you had. (4x4, 5x4, 6x4, etc.)

Also, many don't realize it, but the modern overdrive boxes are all "turned around" from the factory, with the X-pattern shift tower that reverses the right gate for a normal shift pattern. So if you get on the radio and brag about "having it up against the dash!", your tranny will believe you, 'cause that's what it thinks is happening, but most of the rest of us are gonna know your most likely full of it.

 

Not sure you and I are talking about the same thing Hammer. From reading the OP's post, I got the impression that he thought EVERY TIME he pushed the little red button toward the dash, he was in an OD gear. In other words, it was my impression that he thought a 13 would have an OD gear for every hole.

 

Not sure what you call "modern" , but my 1986 15 single OD trans is most definately up against the dash in OD.