1988 Nissan 55HP Lower Unit Issues

[Harritwo]

​I have my lower unit torn down and need help identifying the issue. Transmission does what it wants to, regardless of where the shift lever is placed. Shift rod is moving up and down when the lever is moved. I originally thought the cam was bad, broken or disconnected but that is not the case. I have tried three times to upload photos, so i can also use advice as to how to get the photos uploaded so you can see what i see.

If the clutch is bad, what would i look for? What symptoms would it give?

 

[Harritwo]

Think i got the photos here.

http://s722.photobucket.com/user/george_harris5/library/

 

[pvanv]

The picture doesn't show all I would want to see... is the spring OK? If the ears on the clutch dog are rounded or broken, it would chatter. What are the actual symptoms? It should look more or less like this:

 

[Harritwo]

Paul, i edited the pics and put all i have. What am i looking for in the spring besides it being broken?

 

[Harritwo]

This was the original thread,

http://forums.iboats.com/forum/engi...57380-1988-nissan-55-hp-transmission-problems

 

[pvanv]

The gears and the clutch faces look OK from a distance. Pop the prop shaft out of the "spool" housing (once the prop nut is off, you can just whap the prop shaft end straight down on a wooden bench), and the shaft (and C gear, ball bearing, and clutch and all) should slide out of the needle bearing and casting... and then disassemble the guts to the clutch (following the diagram above), and see if you have any missing or broken bits. There needs to be the push rod, then the ball, then the clutch... pull the pin and the spring will pop everything out) then the spring/clutch holder, which is a cylindrical slug, and then the spring. If the ball is missing, weird things can happen.

 

[Harritwo]

Paul,

Looking at your diagram and trying to free things up, Piece 6 is sheared. Still trying to get the rest of it out and will post pictures when i get whats left out. Is Piece 6 available or will I need a new clutch? Also the seals and gaskets needed to put this back together, are they available or will I win up doing some good ol fashioned Southern Engineering?

 

[Harritwo]

Photos of clutch torn down. Can this b repaired or do I need a new clutch? What is available? Clutch? Repair kit? Pin? Seal Kit?

When you look at the pin, it is in 5 pieces. When you look at the gear and the clutch dog face, there is wear on the dogs. Can any of it be salvaged? If the clutch is not available, and the gear and dog need to be cleaned and trued up, do you know what the base metal is to weld up so it can be machined back down?

Any thoughts, ideas, parts-availability information are all appreciated.

http://s722.photobucket.com/user/geo...?sort=3&page=1

George

 

[pvanv]

George,

As I am no longer actively turning wrenches at the shop, I will be of limited help to you. Biggest issue is that the parts catalog is hard to come by, so getting a part number is tricky. Once you have a number, you may or may not be in luck. I would call Tohatsu Americe at 214 420 6440 to see if they can help you with superceded part numbers. IIRC, the 55 is similar to the old 50, but I'm not sure about the LU components. The gears are very hard, heat-treated, and refacing will be tricky as well, but yours is not completely shot.

 

[Harritwo]

I ordered my parts from Tohatsu America, will update when i have it together and running once more. Thanks Paul

 

[Harritwo]

Lower unit is back together, installed on boat. Fired off engine on muffs, transmission shifting as designed. Will test waterborne in the near future. Many thanks to Paul and Iboats for the assistance with troubleshooting and repair. While the engine is obsolete, no more than it is run and the pleasure it gives my Father is well worth what it takes to keep it running and allow him on the water.