Replacing reverse gear or dog

[legalfee]

I suspect I have a worn reverse gear or dog. I have a 1995 90HP and it clicks and barely moves in reverse. The alignment looks right. How hard is it to replace one or both of these gears? Does anything else need to be replaced (gaskets, seals, etc...)?

 

[blackd]

I replaced a dog this year and on that 1995 Merc LU was very simple. Pull the prop. take out the carrier bolts, pull the carrier. Replace the dog, reverse the pull ... process, fill with oil and get back on the water . IIRC took a little over an hour. BTW, stop babying it into gear. ;-)

 

[legalfee]

Cool. Thanks. It didn't look that hard in a video I just watched. Yes I'll quit babying the shifter I'm still learning - first boat.

 

[jerryjerry05]

The dog is fairly easy.
It can be flipped and use the other side.
Changing the gears needs a factory manual.

You can machine the gear/ dog contact surface and just reuse the old.
It's best if you can get it milled by a pro.

 

[legalfee]

Do the springs, pin, and cam follower kit need to be purchased as well as the dog clutch?

 

[catfishcarl99]

I had to replace my dog on my 50 hp due to wear because I eased it (clicking into)gear. I learned after speaking to a few mechanics that you have to pop it into gear fast. then throttle up. ya I thought easing it into gear was better. but was grinding off my mating surfaces.

 

[jerryjerry05]

No the spring and other parts shouldn't need replacing.

 

[legalfee]

I had to replace my dog on my 50 hp due to wear because I eased it (clicking into)gear. I learned after speaking to a few mechanics that you have to pop it into gear fast. then throttle up. ya I thought easing it into gear was better. but was grinding off my mating surfaces.

When you shift down fast in reverse how far do you go? Halfway and then down more to accelerate?

 

[blackd]

I shift FIRMLY into reverse hesitating just after getting into gear then adjust from there.

 

[jerryjerry05]

Shifting: there should be enough space to shift firmly into gear without engaging the prop.
Shift then pushing further should engage the prop.
If not the linkage needs to be reset.

 

[catfishcarl99]

if your linkages are hooked and set properly you should hear and even feel a thud when the dog engages. my shifter kind of feels firm after that point. then throttle up. it should be obvious when you are fully engaged. should be a thud/clunk sound. shifting slow or easing it into gear you hear several clicks or grinding sound. that's not good. a quick thud. that's good.

 

[jerryjerry05]

Slow shift is a NO!!!
Push firmly.
Feel the clunk.

 

[legalfee]

Good video on dog clutch replacement

 

[jerryjerry05]

That's a good video.
Just make sure the engaging edges of all the gears are good enough to work.