2004 Yamaha 150 HP VMax OX66 TRP

[Captain Steve]

Hey Guys,
I have a '04 150 HP Vmax OX66 with a a TRP Lower Unit. Boat was running great today, and on the way in, I was rnning about 4K RPM's, and I slowed down to about 3K rpm's to take a turn, and when I come out of the turn and straightened her up, I hammered down on the throttle.... When I hammered down, it sounded as if she popped out of gear, made like a thdthdthdthdthd, sound. I pulled her into neutral, then tried to put her back in gear, and the same thing.... its as if you are bumping her into gear slowly, and the gears are grinding...... I still have reverse, but cannot get her into forward gear. I pulled the cowling, and the the shift linkage is moving all the way forward like its supposed to.

Any ideas where to start, or what may be my problem?

Thanks,

[TownsendsFJR1300]

Something IS amiss in the lower unit.

Wether let loose, bent, etc, it needs to come apart. Should be pretty apparent once opened up as bad as it sounds...

[99yam40]

drain lower unit to see if lots of metal is in lube.
might have a bent shift shaft or other linkage

or something very bad has happened inside

[Captain Steve]

Drained Lower Unit Gear Oil

I drained the lower unit gear oil this afternoon, no chunks, nothing out of ordinary on the magnetic plug. No water in lower unit gear oil.

Less than 400 hours on lower unit, haven't hit anything and she has been running great.

[Captain Steve]

Why

Any idea what would cause it to just take a crap?

[99yam40]

until you find out what is wrong you will not find out what caused it.
I would say to drop lower unit then shift it by hand to see if you can feel any difference when turning the prop.
Maybe it is just in the linkage ,not the lower gears themself

[TownsendsFJR1300]

When you say the LU has 400 hours, is it a re-built unit???

Or original (to your knowledge) with the engine...


If it's a re-built, there's been numerous RECENT threads about rebuilt LU's failing earlier than Factory assembled ones (due likely to incorrect set up)

***What can happen too (very easily) is if someone, engine NOT RUNNING, FORCES THE SHIFTER INTO GEAR, very bad and can bend linkages..


As noted previously, you need to get into the unit and see whats going on inside..

[Captain Steve]

Original hours

When you say the LU has 400 hours, is it a re-built unit???

Or original (to your knowledge) with the engine...


If it's a re-built, there's been numerous RECENT threads about rebuilt LU's failing earlier than Factory assembled ones (due likely to incorrect set up)

***What can happen too (very easily) is if someone, engine NOT RUNNING, FORCES THE SHIFTER INTO GEAR, very bad and can bend linkages..


As noted previously, you need to get into the unit and see whats going on inside..

To my knowledge, it is 400 original hours on motor and lower unit. I am going to call Yamaha with the SN to see what they have on it from servicing. I was told it was in the shop every 100 hours for servicing, and I have paperwork to support that. Only thing is paperwork doesn't list SN, but it does list the make, model of boat/motor, and original owners name and number.

I had to leave country today on a short business trip, but I will drop the lower unit as suggested when I return in 10 days, and will let you guys know.

Thank you for all the help.

Cheers,