1985 kenworth w900b project

Can anyone tell me difference between a rto12513 vs rto 14613 speed tranny? I have the old k100 tranny still was thinking slapping it in the w900 till i get the other tranny.

ALSO is there a length difference between the 13 speed eatons? I am tempted of pulling the one from the peterbilt which is only a year or two old to put in the w900

Im without a truck till something is figured out. So trying weigh my options as the one rep isnt much on eta dates...

 

Shop got the warrantied reman tranny in.... are these supposed to whine really loud in the high end after splitting? Been 5 plus years I just don't remember

 

3rd load with the ole girl still have a bunch to fix but road legal and dot passed.

 

Had the fun experience of learning to change wheel seal before being loaded. Learned from going out west you carry parts and tools to do about anything. But from that issue it's the last pig load up there I guess. Which is fn dumb but that's trucking. Pto being installed next week.

Thanks for the transmission pictures and the advice. I look at my bag height this weekend and look at the angle of my 4 driveshafts as well.