Post Damper Plate Replacement
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=40643
Printed Date: October-07-2024 at 2:32am
Topic: Post Damper Plate Replacement
Posted By: lgoldring
Subject: Post Damper Plate Replacement
Date Posted: March-06-2017 at 6:15pm
| After replacing the damper plate on my 1983 PCM 351w, took her for a sea test and acceleration felt sluggish. Before we went out, and after using a feeler on the coupling we determined that alignment was ok, though I noticed the packing nut shimmy ever so slightly. I do plan on rechecking and adjusting any gaps in the coupler again, and my question is, if out of alignment even ever so slightly, can that affect performane of the prop? |
Replies:
Posted By: 8122pbrainard
Date Posted: March-06-2017 at 11:55pm
|
Lee, How far out was the alignment? "Ever so slightly" isn't very technical!  How's you shaft alignment in the cutlass and through the log? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: lgoldring
Date Posted: March-07-2017 at 12:46am
|
Thank for your response, and I realize that my post sounded a little foolish, and it was; once I discovered tonight that the feeler I was using at the marina this weekend was not .003 or less, it was .010. That would of course indicate that there was an unacceptable gap around the coupler. I do have a brass shim now, that I put a micrometer to and it is .003. I will try again this weekend. It is likely the alignment is out, because to replace the damper, we pulled back the shaft, removed the coupling, lifted the tranny and engine with a scissors jack, carefully blocked the engine with wood, removed the jack, removed the bell housing and tranny, replaced the damper, and reversed the process. That's a lot of pulling and pushing... I would also like to add that before and after replacing the damper, I noticed that when rotating the prop shaft, the strut was "groaning" a bit, and it has never done that before, even when the boat has been out of the water for a while. Stops when I wet down the shaft log and when in water though. Therefore I plan to check the clearance carefully around the strut bearning, as well as the entry point into the boat (use a zip tie and check clearance around the shaft I believe I read). Another observation I had after damper installation was some dripping of the packing nut; usually it is very little, say 4-5 drips a minute if that. Now a steady drip. Could be because I backed the shaft through it a few times, but to me it might also indicate that I am out of alignment. ? While I am planning on trying again and adjusting things this weekend, I wanted again to confirm that this is likely the cause of the sluggishness I felt when starting to accelerate through the water. ? Perhaps it really doesn't take much mis-alignment. Thanks again for your insight. |
Posted By: 8122pbrainard
Date Posted: March-07-2017 at 6:27am
Lee, I have a feeling you don't understand the principle of the .003" gap. You are not checking for a gap but rather checking for parallelism between the faces of the couplings. The .003" is the difference or max out of parallel. IE:, you can use a .010" feeler and a .013" feeler. The alignment concept is you want the shaft to run straight aft from the engine/trans so it's not putting a radial load on itself and the engine/trans. Have you watched the http://www.correctcraftfan.com/forum/forum_posts.asp?TID=21279&title=shaft-strut-alignment-video" rel="nofollow - alignment video?
------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
lgoldring wrote:Posted By: lgoldring
Date Posted: March-07-2017 at 5:28pm
| I had watched the video, and will do so again, thank you. |
Posted By: SNobsessed
Date Posted: March-07-2017 at 9:08pm
|
It is normal for strut bearing to squeak if dry. Sounds like shaft packing needs adjustment or replacement. If you replace, get gore-tex material. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |