prop shaft play

[Rbryan94]

I have an 88 Chris Craft 290 Classic w/twin 4.3 Mercruisers Alpha One Gen One. Both drives are right rotation. I've had no issues with these drives. I noticed more play in the starboard prop shaft (about 3/8") than the port (about 1/16") . I tore the drives down and replaced all oil seals and o rings. Pressure tested both drives while turning prop, held 15 lbs with no issues. Before I put these drives back on the boat I was hoping somebody out there might know if that's within spec. Thank you in advance for any feedback.

 

[achris]

Re: prop shaft play

I have an 88 Chris Craft 290 Classic w/twin 4.3 Mercruisers Alpha One Gen One. Both drives are right rotation. I've had no issues with these drives. I noticed more play in the starboard prop shaft (about 3/8") than the port (about 1/16") . I tore the drives down and replaced all oil seals and o rings. Pressure tested both drives while turning prop, held 15 lbs with no issues. Before I put these drives back on the boat I was hoping somebody out there might know if that's within spec. Thank you in advance for any feedback.

Check your reverse gear backlash. There is no spec, but that sounds a little much. (3/8")

 

[Bondo]

Re: prop shaft play

Ayuh,... Welcome Aboard,.... Every Alpha drive I've ever lain a hand on had 'bout 1/8"- 3/16" prop shaft play, in, 'n out,...

 

[Rbryan94]

Re: prop shaft play

Thank you for the response. I'm going with the , if it isn't broke don't fix it. There is no side to side movement only in and out. I'm just hoping it's just one of those things.

 

[Bt Doctur]

Re: prop shaft play

3/8ths is still way out of spec. your sure its a prop shaft and not the prop hub?

 

[Rbryan94]

Re: prop shaft play

I measured the shaft end play with a caliper. I marked the shaft with a pencil to where it stopped. It was 9/32 " better than the 3/8 I thought previous. Does that look a little better. Keep in mind I had no issues with the drive last year. (It had the play last year) No leaks held pressure fine when I pulled it out and holds pressure fine now. Again I appreciate any feedback you have. What a great site!!