C71 Borg Warner res seal replacement

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captbuddy

Veteran Member
Joined
May 28, 2016
Messages
81
Location
United States
Vessel Make
1978 Prairie 29ft.
Need to replace rear seal but was hoping someone could help me on how to remove the coupling so I can get to the coupling nut on the transmission shaft.
 

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When I did mine I removed the transmission. The rest was pretty straightforward IIRC.

Is this how you are approaching the task?
 
If you have clearance to move the shaft and prop back a bit, you can unbolt the coupling and slide the shaft back for access.
 
When I did mine I removed the transmission. The rest was pretty straightforward IIRC.

Is this how you are approaching the task?

No Jeff, I was planning on replacing it with transmission in place watched a utube video and it seem pretty simple if I can get my shaft back a little bit
 
You have a drive saver disc between the two coupling flanges. After unbolting the rear (aft) flange from the drive saver disc rotate and wiggle the shaft rearward and see how much clearance you get. Hopefully enough. I used a tire iron with two bolts protruding to hold the shaft from turning while removing the drive saver disc. After removal of the disc you can access the large coupling nut. I forget the size, Been a few years since I did mine. Best to use a 3/4" breaker bar with a 3 ft pipe over it for a cheater to break it loose. Remove the flat washer under the nut and then wiggle the coupling off the splines. Pry out the old seal and wipe out bore till clean with a rag. Spread a light coat of permatex or your choice of sealer on outside of new seal and tap it into the bore. Make sure to face the lip of the new seal facing fwd. Lube the coupling where it rides in the seal with some oil or grease. Check the coupling for wear on the seal area. If it's badly worn you can relocate the seal in or out a little bit so it rides in a different area of the hub. Do this before insalling seal. If hub is badly damaged replace it. Also use a new nut. Tighten the **** out of the nut or it will come loose and you will have to do the job again. I had to chainfall the trans up to get clearance to do mine. whole job takes about 2 hours. Good luck.
 
Just saying thanks to everyone that gave me advice. Job is complete and I didn’t have any bolts or washers left over. Waited a day and put new fluid in. Ran engine put in gear and no leaks. It’s a good day. Thanks
 
Guy’s after I finished putting everything back together there seems to be a very slight miss alignment of the shaft. Can someone tell me the trick to putting shaft back exactly like it was. Thanks
 
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