727

Would like to switch out put and tail shaft on my MH tranny. it is a 1976 3898870 model. I found a 727 tail shaft 18 in long complete with output shaft. What do i need to know to confirm it will fit? I have read that in 76 they changed things and the shaft from any tranny may not fit.  

They did change the spline pitch angle on the output shaft in 76 so if the one you have for it is from a older trans. it won't work. Actually it'll fit but the splines don't engage properly and will strip quickly. But you can also switch the rear planetary assemblies with the ones that came from the trans. you got the output shaft from. BTW: I assume you realize this means completely disassembling the trans. to do this job since the output shaft comes out the front. If you do this make sure and check and adjust the end play in the planetaries and total end thrust play so it'll work properly and live long.  

Thanks, So in a nut shell if i get the planetary, shaft and case, dive in head first with books and torch i ought to be able to pull the guts out and switch out the inners and she will work? Last time i rebuilt one was 1978 so it ought to go reasonable well. Think I'll go for it. Let you know how it went when i get the parts.