I bought a fully splined th400 slip yoke for my 4l80e. It is from a 2004 van. It appears to have splines all the way down the output shaft. I don't see an oring on the splines but my yoke will only slide on 2.5". I am assuming I need a counterbored yoke but I have read with the new van output shafts this is not needed. The o ring I can see is on the face and the end of the splines. If a counterbore is needed I can machine that in if someone can give me a diameter of counterbore and a depth. Yoke is a new spicer and visually looks good.
I am not sure what is causing my problem. Doesn't feel like a vaccum lock.
Thanks for help in advance,
Josh

 

Is it possible the slip yoke is not engaging the tail housing bushing? Maybe it's a bit to large and the bushing needs honed?

Is there fluid in the tranny? Maybe pull the tailhousing off and investigate more?

 

No fluid in tranny. Looks like I will remove tail housing next. Bushing could be problem.