zz28zz

While I had the drives off, I notice on one of them, the input shaft had a small amount of in/out play.
I spoke to a marine mech today and he said the input and prop shafts normally have a small amount of in/out play.
One of the forum members said there should be no play.
Wondering if maybe the new/rebuilt spec is zero play, but after a few hundred hrs, a small amount of play is normal??

I watched a youtube video of the input shaft bearing pre-load being set. I can't tell where the slop would come from.
Pinion gear nut backing off? Bearings wearing out? Spacer worn? Retaining nut/ring backing off?
Seems to be multiple possibilities. Which is most likely?
I don't know the true hrs on the drives. I suspect they may have 600+ hrs on them.
They work great and the chip detectors come out clean every time I've pulled them.

https://www.youtube.com/watch?v=lPr4UQPMBXg

motor

iTrader: (3)

That marine wrench was wrong,there should be no in/out play on input shaft

zz28zz

Does the in/out play mean I need to adj/shim something or replace something/s??

Dilligaf59

That so called mechanic is WRONG on both ends! There is no end play on any shaft on any Bravo. EVER

I'm shocked that you're magnets are clean. It is going let loose but when is always the question. It's a Bravo, they do that!

It's probably not something you are set up to do.

Mr Gadgets

Typically on well used Bravo's the thrust washer that the yoke seats on and it press against the outer most bearing will spin and wear. I believe that is where the pencil lead dust comes from on the magnets.. As well as other sources of metal wear. But enough wear on that washer and your preload goes away. Then the pinion gear is able to move side to side as torque is applied to the drive. Eventually something will break or wear out due to the lack of preload. At 600 hrs, it is probably time to have it opened up and rebuilt.
Hope that helps..

zz28zz

Thx for all the replies guys. Apparently the ol marine tech was wrong. Just for the record, I've never met the guy before and don't know anything abt him. I just stopped into his shop to see if he had any high-perf lube and we got to talking abt the input shaft slop I had noticed. I'll be sure to steer clear of that shop for any maint work.


Mr Gadgets:
Would the thrust washer you're referring to be item #30 on this diagram?

http://www.mercruiserparts.com/Show_...TER+COMPONENTS

BTW, the Merc service manual refers to this part as "Washer (beveled)".

zz28zz

I pulled the pinion gear assy out and inspected the gears and bearings. The gears look new and the bearings felt very smooth. I tightened the pinion nut just a hair and re-installed the assy. Still had some in/out slop. Removed assy and tightened nut another hair and repeated this process abt 10 times until the in/out slop was gone. I'm confident the bearings don't have too much preload. If anything they are on the loose side but much better than the way it was. I'm planning on running this way until the end of the season (maybe 10 hrs) then will tear them all down over the winter. Currently in the process of researching what special tooling I'll need.

For the pinion gear assy repair (bearing replacement), I know I'll need the following special tools:

bearing driver for oil seal carrier.........................91-89868
driver for small bearing to pinion gear............... 91-90774
bearing puller plate............................................ 91-37241
Spanner wrench............................................ .... 91-17256
Dial type in-lb torque wrench

I'm sure when I get it all apart, I'll have more questions.
Thx for the input.

Mr Gadgets

Yes that is the washer I am referring to..