i have a dana with the shift in the upper.. ran like a dream.. i used to hear a hissing noise up by the helm.  today pulling into a gas dock the reverse did not engage..i shifted it into neutral and reverse a couple times and it engaged...but now it only work intermittantly...i can see the clutch move and the shift moves on the outdrive...by the end of the day  sometimes it wouldnt engage in forward nor reverse...also i could not heard that hiss noise at the helm...what is the booster _link_ and where would i find it???    any thoughts???  when it does engage there is no clunk and it feels solidly engaged

Never heard of a hissing noise.

1 Check the booster _link_ for broken springs. It is the piece that is between the shifter lever and the shifter bar that the cable connects to on the side of the out drive.

2 Make shre that there is some freeplay in the clutch adjustment

3 The splines wear out on the connecting shaft in the clutch plate and this results in "no drive" foreward or reverse.

Call Me 251-968-3903 I will be back thursday evening.