Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 21-09-2018, 22:13   #1
Registered User

Join Date: Nov 2016
Posts: 120
How do I replace rear seal on transmission

Hello,


We have recently found that our transmission was leaking oil. I used UV dye and traced the leak to a spot highlighted in the three attached images. Note all images highlight same spot from different angles.


It seems to me that if the leak is coming from that spot, the rear seal on the transmission must be failing. Can anyone confirm this?


Also, would it be possible to replace the seal with the transmission attached or will it need to be removed?


Thanks in advance for any help.


Volvo penta 2003B with ms2 transmission
Attached Thumbnails
Click image for larger version

Name:	trans4.jpg
Views:	185
Size:	126.2 KB
ID:	177778   Click image for larger version

Name:	trans3.jpg
Views:	184
Size:	87.1 KB
ID:	177779  

Click image for larger version

Name:	transmission.PNG
Views:	173
Size:	173.3 KB
ID:	177780  
__________________

redbeard1 is offline   Reply With Quote
Old 21-09-2018, 22:43   #2
Marine Service Provider
 
Emmalina's Avatar

Join Date: Jan 2012
Location: Thailand
Boat: Herreshoff Caribbean 50
Posts: 543
Re: How do I replace rear seal on transmission

Yes just unbolt the nut in the middle and pull the output flange off. It will be a standard of the shelf seal. Rebuilt one many years ago. Says it has no oil in it
__________________

__________________
Steve .. It was the last one that did this !
Emmalina is offline   Reply With Quote
Old 22-09-2018, 13:14   #3
Marine Service Provider
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,525
Images: 2
Re: How do I replace rear seal on transmission

That is likely to be either a loose coupling flange nut where it secures to the output shaft or a damaged O ring that seals between the output shaft and coupling flange. Your biggest problem will be pushing the prop shaft back far enough to get a socket in there and/or to remove the output flange, looks like you're kind of restricted for room.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 22-09-2018, 13:30   #4
Registered User

Join Date: Nov 2016
Posts: 120
Re: How do I replace rear seal on transmission

Thanks Emmalina,


Do you know where to find a service manual for this reverse gear. I googled but only found some that were missing the photos. I work on cars a fair bit and the factory service manual makes all repairs easy.


Spoke to a mechanic yesterday on the phone. He said I would need to pull transmission and send it to specialist as some of the seals require pressing. Based on your knowledge, is he pulling my leg or maybe there are more than one seal (some easy, some hard)?
Attached Thumbnails
Click image for larger version

Name:	seals.PNG
Views:	93
Size:	301.5 KB
ID:	177794  
redbeard1 is offline   Reply With Quote
Old 22-09-2018, 15:44   #5
Registered User

Join Date: Nov 2016
Posts: 120
Re: How do I replace rear seal on transmission

Quote:
Originally Posted by NoTies View Post
Your biggest problem will be pushing the prop shaft back far enough to get a socket in there and/or to remove the output flange, looks like you're kind of restricted for room.

Thanks, I think you are right. Looking at the manual, I think I may leave this repair to the pros. Or maybe if I feel more brave in a few months.



At a minimum, I'll let our mechanic pull the transmission. Maybe I can do the rest but it does seem to require use of press. Or maybe I'm just reading the manual wrong.



Anyway, for any that want to try this by themselves, here is manual. Relevant section starts on page 34. Note: When I download manual, the pictures are deleted.



https://www.manualslib.com/manual/89...page=39#manual


Thanks to all again.
redbeard1 is offline   Reply With Quote
Old 22-09-2018, 17:34   #6
Registered User

Join Date: Feb 2009
Posts: 1,962
Re: How do I replace rear seal on transmission

I'd say remove the nut pull the flange off, it may require a puller pry the old seal out and bang a new seal in. If you have access to an electric impact gun it would make things easier to remove the nut. If not you will need to figure out a way to hold the flange stationary
motion30 is offline   Reply With Quote
Old 23-09-2018, 09:04   #7
Registered User

Join Date: Jul 2017
Location: Chemainus BC
Boat: Pedrick Cheoy Lee 41 offshore
Posts: 89
Re: How do I replace rear seal on transmission

You don't mention the name of the engine, but when I did mine, on a Perkins 4-108 the new seal came in 2 parts, saving the removal of the output. It was then bolted onto the rear of the transmission. If yo can't get socket on it, use a wrench.
Greg Mason is offline   Reply With Quote
Old 23-09-2018, 09:12   #8
Registered User
 
Scaramanga F25's Avatar

Join Date: Mar 2015
Posts: 593
Re: How do I replace rear seal on transmission

My mechanic raised the rear of the engine off the rear rubber mounts after disassembling the coupling and replaced the seal in place. Then he realigned the engine to the shaft.
Scaramanga F25 is offline   Reply With Quote
Old 23-09-2018, 10:26   #9
Senior Cruiser

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Campbell River, BC
Boat: Union 36
Posts: 106
Re: How do I replace rear seal on transmission

Quote:
Originally Posted by Scaramanga F25 View Post
My mechanic raised the rear of the engine off the rear rubber mounts after disassembling the coupling and replaced the seal in place. Then he realigned the engine to the shaft.
Great time to inspect (replace if any doubt) the mounts as well since itís already undone and will be realigned.
Wulf is offline   Reply With Quote
Old 23-09-2018, 14:15   #10
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 8,536
Re: How do I replace rear seal on transmission

Quote:
Originally Posted by Greg Mason View Post
You don't mention the name of the engine, but when I did mine, on a Perkins 4-108 the new seal came in 2 parts, saving the removal of the output. It was then bolted onto the rear of the transmission. If yo can't get socket on it, use a wrench.
FWIW, the OP mentioned his engine is a Volvo penta 2003B with ms2 transmission.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 23-09-2018, 17:04   #11
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 1,321
Re: How do I replace rear seal on transmission

As noted by No Ties, the problem is likely a loose flange nut, item 80 below. The oring, item 78, that prevents oil from seeping out via the shaft splines, could also be bad.

If the lip seal, item 74, p/n 873100, were bad the gearbox would be leaking from another place, between the lip of the seal and the sealing surface on the output flange, item 79, and oil would be present on the forward side of the flange.

It looks like you might have just enough room to get a socket in there to tighten the nut. If so, do so and see if that solves the problem. Do not be tempted to hold the gear from turning by holding the nut on the front of the engine; put two bolts in the flange and use a prybar to keep the shaft from turning as you tighten the nut.

If you (or your mechanic) have to replace the oring 78, and can't get it out with a hooked pick, or you can't get the flange off because of clearance issues, you may need less clearance to remove the output shaft and housing 64 as a unit and work on it on the bench. You have to remove three bolts 68, 77 holding the cooler manifold 67 and then the six socket head cap screws that hold the housing 64 on (they aren't shown in the drawing) and then the whole assembly has to be, if memory serves, pulled back about a half inch before it can be tilted and removed. It is shimmed and sealed with an oring 75; make sure you put back the shims 57, I've always just reused the oring, but if you're changing the oring 78 and have it off, why not change that one too. Same for the lip seal 74 and any others that are now accessible...



jimbunyard is online now   Reply With Quote
Old 23-09-2018, 21:26   #12
Registered User

Join Date: Nov 2016
Posts: 120
Re: How do I replace rear seal on transmission

Quote:
Originally Posted by jimbunyard View Post

If the lip seal, item 74, p/n 873100, were bad the gearbox would be leaking from another place, between the lip of the seal and the sealing surface on the output flange, item 79, and oil would be present on the forward side of the flange.

Thanks to all for the replies and thank you Jim for referencing the diagram. I'm pretty sure the only oil I saw was on the shaft, but I'll go back to the boat this week and confirm.


One thing keeps bothering me. If the oil is leaking onto the shaft and the shaft is spinning. Wouldn't the centrifugal force splash the oil all around the area? Unless, the oil leaks after the engine has cooled down.



I went to boat today to look for this splash/spray but found none.
Attached Thumbnails
Click image for larger version

Name:	DSC_2743.jpg
Views:	36
Size:	405.5 KB
ID:	177859  
redbeard1 is offline   Reply With Quote
Old 24-09-2018, 00:56   #13
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 1,321
Re: How do I replace rear seal on transmission

Not sure if I'd strictly call this a leak; seems more of a seepage. If it were serious enough the oil could be thrown around by the spinning flange, but it's have to be pretty serious, and the flange would be oily on its' forward face. Think about the drip from the stuffing box when the shaft is spinning...

As the gear is lubricated by splash/immersion (there is no oil pump) the only 'pressure' supplied is that induced by the spinning parts and the expansion of the oil when hot. Make sure that you are not overfilling the gear, as even a slight overfilling could cause the kind of seepage you're describing. You might try only checking the oil when hot, or running the level slightly below the full mark, it is not uncommon for 'fill' marks to be somewhat less than optimal...

By the way, if you have to remove the output shaft/housing assembly to get at the spline seal ring, my faulty memory strikes again. the bolts holding the housing on are shown, items 76 and 77. 77 has the dual purpose of securing the cooler manifold and the rear housing; bolt 68 is a retainer bolt for the manifold, it need not be removed to remove the assembly.
jimbunyard is online now   Reply With Quote
Old 24-09-2018, 09:18   #14
Registered User

Join Date: Nov 2014
Posts: 752
Re: How do I replace rear seal on transmission

The "proper" way to replace the leaking shaft spline "O" ring is to remove the output shaft bearing carrier from the gearbox housing, remove the flange nut, pull the output flange off the shaft with a puller, press the shaft out of the bearings, replace the crush sleeve found between the bearings ( item 71), replace the oil seal, reassemble everything using a new "O" ring on the shaft and a new flange retaining nut, and tighten the nut to the proper rolling torque to correctly preload the roller bearings on the output shaft. Then reinstall the bearing carrier with a new O ring.

Could you remove the nut, the flange, remove the O ring with a thin pick,and reassemble everything with a new seal and O ring and still get the bearings preloaded correctly? Maybe.......

DougR
DougR is offline   Reply With Quote
Old 24-09-2018, 13:23   #15
Registered User

Join Date: Nov 2016
Posts: 120
Re: How do I replace rear seal on transmission

Quote:
Originally Posted by jimbunyard View Post
Not sure if I'd strictly call this a leak; seems more of a seepage.



I agree, leak is too strong, best call it seepage. Best guess, we are losing a teaspoon every hour of engine run-time.



Late August, we found oil in the bilge. We looked at transmission oil and discovered the level was just above the bottom tip of the dipstick. We filled the transmission at that time to the max level and the level today seems only a little lower.



Quote:
Originally Posted by jimbunyard View Post
Make sure that you are not overfilling the gear, as even a slight overfilling could cause the kind of seepage you're describing.
We filled to the top notch mark (measured when fully inserting the dipstick). Most forums say to only insert dipstick until the base of the dipstick handle touches the top of the transmission. Based on this latter method, we are possibly under-filling transmission by a little. The manual does not describe the exact method to use.






Thanks for all the help. I'll be at the boat Wednesday. I would like one last run to confirm the source of the leak. Assuming, I find oil on the shaft again, then we will have our mechanic pull the transmission and send it to a specialist over the winter.


Thanks again to all.
__________________

redbeard1 is offline   Reply With Quote
Reply

Tags
transmission

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear Main Seal Leak gettinthere Engines and Propulsion Systems 4 17-09-2018 12:45
Yanmar SD50 Forward Seal Service Interval and Engine Rear Seal? cdiversions Propellers & Drive Systems 4 24-12-2016 19:10
Transmission Rear Seal Replacement boeing1 Propellers & Drive Systems 7 23-12-2014 09:56
Replace rear main seal in the water? montenido Engines and Propulsion Systems 8 14-05-2013 05:30
Rear Main Oil Seal - Volvo MD17c SabreKai Engines and Propulsion Systems 3 01-11-2010 17:09



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:30.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.