SailNet Community - Reply to Topic

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Engines > Diesel > Is it normal for the drive shaft to move in an out by half an inch??
 Not a Member? 


Thread: Is it normal for the drive shaft to move in an out by half an inch?? Reply to Thread
Title:
  

By choosing to post the reply below you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Topic Review (Newest First)
05-23-2012 04:45 PM
dabnis
Re: Is it normal for the drive shaft to move in an out by half an inch??

Quote:
Originally Posted by justonemoreproject View Post
I replaced the pulley on my driveshaft with a larger one so my alternator would spin faster at low RPMs. During the process, I noticed that my driveshaft moves in and out about 1/4 to 1/2 inch. is that OK or should it not do that? I wonder if I caused it to do that when I was trying to pry the old pulley off with a screw driver? I am guessing I put about 50 pounds of pressure on it. I finally gave up, got a wheel puller and removed it.

When I first started the engine with the new pulley. I noticed that it was rubbing on the engine slightly, but i was able to stop that by pulling the drive shaft away from the engine. I am concerned that it might move back again, so I re-set the pulley on the drive shaft 1/4 of an inch further away from the engine.
Should I be concerned about the movement in the drive shaft and if so, what can I do about it?

Thanks for your help.

Larry
That seems like a whole lot of end play. It appears that the wrist pin is keeping the crankshaft somewhat in place? Whatever thrust bearing arrangement it had appears to be basically gone. Did it have this much play before you pried on the pully? if not you may have damaged whatever was in place originally. If it had that much play to begin with it appears the engine may tolerate it? Suggest you watch it while under power to see if it is moving back and forth. If it stays put you may be lucky enough to let it be. Possibly, excessive movement could result in sudden piston, wrist pin, or rod failure, not good.

Paul T
05-23-2012 03:15 PM
Faster
Re: Is it normal for the drive shaft to move in an out by half an inch??

Quote:
Camshaft end float ................................ 0.003/0 010in (0.08/0.25mm)
Crankshaft end float (new)........................ 0.005/0 01 Pin (013/0 43mm)
Crankshaft end float (not to exceed)......... 0020m (0 51mm)
From this site: http://www.eygthene24.com/images/cm_...petter_AB1.pdf
05-23-2012 02:53 PM
Dog Ship
Re: Is it normal for the drive shaft to move in an out by half an inch??

Now I know what engine you have, single cylinders can handle more end play than a multi cylindered engine. You engine's end play should not exceed 5mm.
05-23-2012 02:42 PM
justonemoreproject
Re: Is it normal for the drive shaft to move in an out by half an inch??

Wow. Lots of responses. Sorry for the lack of clarification.
Sorry for the misinformation. The play is in the crankshaft on the forward side of the engine. Not the drive shaft.
I have a 32 year old Petter, AC1W diesel engine with 750 hours on it. (its in a sailboat that has been used mostly as a liveaboard all these years.
ITs a 6 1/2 HP one cylinder, that starts right even after several months of not being started. It is fresh water cooled with a heat exchanger which is the only reason it has survived all these years. I change the oil, pump out the old diesel and clean the filters once a year, although I only run about 5 -8 gallons through it per year.
I have never had a problem with this engine.
Thanks for your help.

Larry
05-23-2012 01:37 PM
Dog Ship
Re: Is it normal for the drive shaft to move in an out by half an inch??

It is your thrust bearings that have failed.
These bearings go on each side of the shell bearings on each main journal and stop crank walk. There should only be tops 8/1000" end play in your crankshaft.
If you have a lot of end play, pull your oil pan off and look for pieces of bearing material. It will be soft metal, peutor in colour.
Eventually your pistons will start hitting the cylinder walls and this will cause serious fatal damage. It's time for a rebuild before it gets worse and costs you some serious coin.
05-23-2012 12:46 PM
jrd22
Re: Is it normal for the drive shaft to move in an out by half an inch??

Fast- I was thinking "1/2" of movement in the propshaft?", didn't even think about the crank! Ouch! Will wait for clarification from the OP.
05-23-2012 12:45 PM
deniseO30
Re: Is it normal for the drive shaft to move in an out by half an inch??

Quote:
Originally Posted by justonemoreproject View Post
I noticed that my driveshaft moves in and out about 1/4 to 1/2 inch. is that OK or should it not do that? I wonder if I caused it to do that when I was trying to pry the old pulley off with a screw driver? I am guessing I put about 50 pounds of pressure on it. I finally gave up, got a wheel puller and removed it.
Larry
Larry... I hope that wasn't a classic "uh oh" knowing little about the insides of engines but knowing something about crankshafts in hvac compressors I would say it's not good to be prying on them to get things off.
05-23-2012 11:41 AM
arf145
Re: Is it normal for the drive shaft to move in an out by half an inch??

Folks are going to ask you what make of engine, year, condition, details like that. It would be a good idea to put them out there now. Oops, see that Faster is already asking--see?
05-23-2012 11:39 AM
Faster
Re: Is it normal for the drive shaft to move in an out by half an inch??

What engine? Can you post a picture? Not too sure what you mean by 'Driveshaft'... if you're talking about the crankshaft then no, definitely not normal- if even possible...

Or are you driving an alternator with the propshaft?? unusual but I suppose it's possible but rpms would be rather low.... Even so that shouldn't move in and out either..

Need clarification!!
05-23-2012 10:58 AM
justonemoreproject
Is it normal for the drive shaft to move in an out by half an inch??

I replaced the pulley on my driveshaft with a larger one so my alternator would spin faster at low RPMs. During the process, I noticed that my driveshaft moves in and out about 1/4 to 1/2 inch. is that OK or should it not do that? I wonder if I caused it to do that when I was trying to pry the old pulley off with a screw driver? I am guessing I put about 50 pounds of pressure on it. I finally gave up, got a wheel puller and removed it.

When I first started the engine with the new pulley. I noticed that it was rubbing on the engine slightly, but i was able to stop that by pulling the drive shaft away from the engine. I am concerned that it might move back again, so I re-set the pulley on the drive shaft 1/4 of an inch further away from the engine.
Should I be concerned about the movement in the drive shaft and if so, what can I do about it?

Thanks for your help.

Larry

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


All times are GMT -4. The time now is 08:56 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.