T 10 jumping out of gear

[6R09K]

I had this problem back in 1975 for a BW T-10. The output shaft moved too much and Ford sold a packet of different thickness snap rings that fixed it. Sorry I don't have that old Ford part #

[gt350hr]

  +1 , minimal end play is another key factor to keep the transmission from popping out of gear. It is very tough to eliminate all end play as we are dealing with ball bearings that have inherent play in them. The large snap ring in the aluminum "mid plate" is most responsible for end play in the T-10 . Over time ( 50 + years) the receiver groove in the plate "hammers" a bit and end play increases. If the end play is extreme , the plate must be replaced as there isn't a sure fire way of reducing the play.
     Randy

[csxsfm]

I had the problem and the excessive "end play" was caused by a cracked aluminum tail housing.