No Reverse

[RedRascal]

Out cruising the San Juan islands in Washington and lost reverse. Symptoms started with a delay shifting into reverse and "slipping" sometimes when applying a few hundred rpms above idle. Forward is working great. Tranny is a Paragon 6E-6350. P33AL connected to a 120 Lehmann in a CHB 34. Linkage is shifting fine on transmission and fluid level is full. At this point you shift in reverse it doesn't engage at idle or higher rpms.

Questions:
How many running hours until we lose forward? I would assume we can get more hours out of it running with a light load.
Any good Paragon transmission mechanics in Anacortes Washington to call?
Any things to check or tighten.

 

[tiltrider1]

Have you tried adjusting the cable. Are ou sure that the shift lever on the transmission has reached the full length of its travel.

 

[RedRascal]

Have you tried adjusting the cable. Are ou sure that the shift lever on the transmission has reached the full length of its travel.

Yep we looked that on top of the transmission, shifters are moving correctly. We were hoping for a simple linkage adjustment but no go.

 

[artfulltune]

With twin Perkins connected to Borg Warner transmissions I went 2 seasons without a starboard reverse. While on the hard last year I had the transmission rebuilt. Cost was north of $7k. Good luck with yours.

 

[Comodave]

Have you unhooked the shift cable and tried shifting it with the lever yo make absolutely sure it isn’t the cable? Worth 5 minutes just to make sure. It may look like it is moving but maybe, hopefully, it is the cable.

 

[gordytwo]

I've fixed a few of these with no reverse. Since you have checked the linkage it probably is a failed reverse piston seal or a broken reverse band anchor strut. Both can be fixed without removing the transmission if you haven't burned up the band.

 

[C lectric]

https://www.harbormarine.net/

https://www.harbormarine.net/transmission-service

No dealings with them so just a suggestion.

 

[RedRascal]

With twin Perkins connected to Borg Warner transmissions I went 2 seasons without a starboard reverse. While on the hard last year I had the transmission rebuilt. Cost was north of $7k. Good luck with yours.

That's encouraging given that we have about 4 hours of running time left to get back to the dock.

 

[RedRascal]

I've fixed a few of these with no reverse. Since you have checked the linkage it probably is a failed reverse piston seal or a broken reverse band anchor strut. Both can be fixed without removing the transmission if you haven't burned up the band.

Our fingers are crossed that we can get away with popping in a new seal. Once we noticed the issue we would only use reverse at idle to minimize the risk of burning up the band. Time will tell if that was enough to save the band.

 

[RedRascal]

https://www.harbormarine.net/

https://www.harbormarine.net/transmission-service

No dealings with them so just a suggestion.

Thanks for the reference, we appreciate it.

 

[sailormike]

please keep us posted as to what you find when you fix it

 

[Choices]

Had the same problem with my Velvet drive. It was a broken circlip.

 

[slowgoesit]

Second the suggestion that you disconnect the shift cable at the transmission and confirm beyond any doubt whether it is the cable/linkage, or the transmission.
Where is your home port? I would be tempted to call Sea Tow and have them tow you in. The more you use it in it's current condition, the less likely it will be easily repaired.

Please keep us advised.

 

[RedRascal]

Update: No issues today making the 5 hour run to the marina in Anacortes Washington. Held the RPMs at 1,450 most of day for an easy cruise back in. As for docking we had slightly favorable light wind that we used to our advantage then just used a spring line to stop the boat. The key was getting close enough to the dock to get a spring line on a dock cleat.

Current theory is an O-ring or seal was failing on the reverse piston in the tranny which caused the sporadic engagement of reverse. As the o-ring/seal was failing the thinking is that it took longer for it to engage reverse or would lose pressure and come out of reverse until the point it failed to hold pressure to get it into reverse.

I am off the boat now(had to return to land life) but my buddy is going to pull the top cover off the tranny in the morning to see if it is a failed o-ring or if a seal is the issue. If not we've learned there is possible band adjustment that can be made by removing a couple tensioning shims.

As for the linkage adjustment we think it is fine. There is an indicator on the top of the tranny that indicates Reverse, Neutral and Forward. The shifter moves the indicator to the appropriate positions. As long as the indicator on the top of the tranny is correct the linkage should be correct.

More tomorrow once we get eyes inside the tranny. Thanks for the comments.

 

[slowgoesit]

Hopefully it turns out to be the o-ring, and it is easily accessible.

 

[RedRascal]

Update = Fixed. Our theory we were thinking about with an o-ring/seal turned out to be wrong. The issue was an internal arm that controls the reverse band had broken. However I was told it was relatively easy to replace by removing the top of the transmission case. No need to disconnect or remove the tranny. Reverse is working as expected again. The win goes to Harbor Marine in Everett Washington for having a brand new arm in stock and a seal kit. I have a connection with the owner of an Anacortes charter company and he said Harbor Marine is his go to place for any transmission work. "C lectric" nailed it earlier in the thread with Harbor Marine.

 

[CHBJim]

Same transmission, same problem

I have the same 1976 CHB trawler, engine and transmission and have lost my reverse three times since rebuilding the transmission in hopes of fixing this problem. Parts and mechanics for this transmission are hard to find in Vancouver B.C. The mechanics whom I have used have adjusted the adjustment bolt with some success but the reverse continues to fail when we go out, sometimes within a month , sometimes within a weekend. There is one shim left on the bolt and there was a suggestion to replace the bolt with a longer bolt. Adjusting never seems to restore reverse 100% but enough to leave the dock. I plan to look into some of the suggestions suggestions on this post. I've had the tranny out twice now and am hopeful that it can be fixed in place. Any further suggestions or comments would be appreciated.

 

[ronobrien]

Yep we looked that on top of the transmission, shifters are moving correctly. We were hoping for a simple linkage adjustment but no go.

I am not familiar with your setup, but a thought I had was to be sure that the shifter shaft is rotating with the lever. The lever may be moving and the shaft may not be.