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85 stars an stripes
05-18-2011, 06:59 AM
I had my transmission rebuilt at the first of last summer well at the end of the summer It Blue the front transmission seal out Which was no big deal because I was planning to rebuild the motor over the winter any way But now that it is time to start using the boat again I have put 4 more seals in the transmission and cannot figure out why it is blowing them out I put a new transmission cooler on it And news lines Any help would be appreciated thanks

Skipper
05-18-2011, 09:57 AM
There is a small retaining clip at the front of the transmission that causes the front seal to fail. I had a similar experience with my '87. Simply reinstalling the seal will not suffice. You have to break down the transmission and make sure that retaining clip is in place.

thatsmrmastercraft
05-18-2011, 10:31 AM
Sounds like I would be going back to where I had the trans work done.

85 stars an stripes
05-18-2011, 11:48 AM
Where is the small retaining clip you're talking about is it behind the front pump is it or is it on the clutches

CantRepeat
05-18-2011, 12:18 PM
Where is the small retaining clip you're talking about is it behind the front pump is it or is it on the clutches

This post has links to the service manual. You can see some exploded views of the tranny.

http://www.mastercraftboats.com/teamtalk/showthread.php?t=32581

I've rebuilt a 71c in my old 92 but I'm not sure what clip he's talking about. From what I remember the pump is bolted to the pump housing and there are no clips. There is a seal ring on back side of the pump housing but I'm not sure that would be the issue.

Have you check to make sure the vent cap on the rear of the trans is not clogged, bent or blocked? If you create to much internal pressure I could see that popping out the front seal.

Skipper
05-18-2011, 02:02 PM
Where is the small retaining clip you're talking about is it behind the front pump is it or is it on the clutches

In the manual CR posted look at the diagram on page 13, item #87 "snap ring". If that is not in place or not seated properly, then when under pressure it will allow the assembly to move along the shaft which in turn allows fluid to leak out.

I had this tranny on my '87. My father-in-law rebuilt it because the shaft was spinning while in neutral. After that the front seal would pop out. I fought it for a while then just bought a new transmission. I sold the old one to a boat shop in Ohio. That guy tore it down and told me that the $0.32 retaining clip was not installed properly which was the source of all my troubles.

I share this with you because the symptoms that you describe are similar to those I experienced. Good luck.

Skipper
05-18-2011, 03:17 PM
Below is a link to the website for the company that I sold my transmission. Eric is the one who figured out that it was the retaining clip.

Source: http://fantasticfinishmarine.net/

CantRepeat
05-18-2011, 03:34 PM
Ok, that makes a little more sense. When you said behind the pump, I was picturing between 106 and 97 which has no ring. The part you referenced is behind the entire pump/clucth housing adapter.

If that ring was not put on right, or has come off the main input shaft I'm sure it would lead to issues. The good news is you should be able to fix it yourself without completely tearing down the trans.

85 stars an stripes
05-18-2011, 05:24 PM
Thanks for the help I will check that link out And hopefully I can fix this