Help identifying Cummins

So I’m assuming the guy that sold me this truck had no clue as to what he had
See image please help identify this transmission

 

Yes and no. That shift knob you have will work fine, just not with the pattern it shows. Start in low, you’ll have your bottom 5. Come it intermediate and go into first….not low then split that one to high. Then shift then split it back to intermediate then high in that gear. And so on… You can’t pre select the old RTO series 13 speeds.

im not handy at explaining thing’s maybe someone else can do a better job of making it easier.

 

I believe this is my shift pattern

do you think this transmission will be sufficient?
After I have motor rebuilt NTC 350 SC I’m going to have a shop go through it too
Also what rear end gear ratio should I run?

 

Yes it will be more than enough

 

I wasn’t privy to that style of 13, either. Bout like shifting the old 10 wheelers I got, with a 5/2 transmission, except this has a low range.

 

The original shifter pic you posted may not work on some because the top position is not a splitter control so the air plumbing is different.

The RTO 9513 was fine behind the NTC 350. 8th OD “13th” gear is super noisy at cruise speeds. But that means it’s healthy. Lol.
Like @wore out was explaining you only preselect the range up or down but you post select from od to dir. you preselect a down shift from dir gear to a lower hole od.

Upshift Pattern low, I,2,3,4. Then preselect
5, split to 5 od. , leave in od shift to 6 and then select to dir for 6. Then split back up to 6od. Leave in od and shift to 7 then select to dir for 7 then split back to 7od. Same thru 8th.

downshift pattern. From 8 od select dir for 8dir. For 7od preselect od and shift to 7od and then select dir for 7. And so on. If you don’t do this it will constantly neutralize even with shifter in a hole.

 

Those 13’s are a pain. You do full gear straight shifts thru the pattern three times with no splits, and it seems like you can never remember what freaking gear you are in half the time. They also top out before you run out of speed limit with low rear gears so not ideal for highway operation.

 

That engine was rated at around 1050 ft lbs of torque oe. So don’t run higher then 355’s. I know guy’s that run 355’s and 370’s and get along pretty good. They arn't in a hurry and and have to be first up the mountain. I have 4:11’s in my ‘67 with a Rto12513. (Same ratio’s) and NTC 350 small cam and tach out 2150 on tall 24.5’s at 74 mph. I run 62-65 99% of the time anyway. Less mental stress for me. Mine new was specced with 4:33’s oe because with the old Ntc335’s at 950 ft torque they were pretty standard in those days. Altho it keeps me rolling a little slow 4:11’s do pull easy on things though.