Mercury V6 School for lower units

**TEXAS20225** · 04-23-2020, 02:44 PM

You are talking about under the forward gear race( or behind it which ever you prefer) shim right???

**TEXAS20225** · 04-23-2020, 02:47 PM

X2 on the mystery shimming especially after 97

**Aaronhl** · 04-23-2020, 03:37 PM

Originally Posted by TEXAS20225

You are talking about under the forward gear race( or behind it which ever you prefer) shim right???

Yea the shim behind the forward gear if you are looking at the teeth from outside the lower unit...guess it's somewhat common not to find one there

**Aaronhl** · 04-23-2020, 03:58 PM

I also previously thought all lower units with the square anodes were non ratcheting...but upon my research of past threads (posts by TEXAS20225) there were stock ratcheting cases made into the mid 90's which were ratcheting AND having the anodes (C1). When looking at various classified websites I was dismissing the anode units right away, but it will come down to the cast number on the unit itself.

**Merc 2.5** · 04-24-2020, 07:28 PM

I actually thought same thing bout anode units not ratcheting. Used to spot the anode and keep scrolling. Thanks for the lesson

**TEXAS20225** · 04-25-2020, 11:50 AM

looking at the teeth out of the case?? im not sure what that means ?? the shim is behind the race which takes a slide hammer to remove in most cases it has nothing to do with geared portion of forward gear bearing which is bearing and race the shim which pushes unit (gear and race closer to pinion) factory says start with .010 in ratchet cases and .020 in non ratchet case's. But as stated and know with out a doubt this means zip in factory case assembly

**Aaronhl** · 04-25-2020, 09:09 PM

Originally Posted by TEXAS20225

looking at the teeth out of the case?? im not sure what that means ?? the shim is behind the race which takes a slide hammer to remove in most cases it has nothing to do with geared portion of forward gear bearing which is bearing and race the shim which pushes unit (gear and race closer to pinion) factory says start with .010 in ratchet cases and .020 in non ratchet case's. But as stated and know with out a doubt this means zip in factory case assembly

ok now I’m confused so the forward gear basically falls out after I take the pinion gear out, There is not much holding it in the lower unit, so when the forward gear(with bearing on it) is taken out, where is the shim? It seems like everything behind the forward gear/ bearing is cast into the lower unit??

**TEXAS20225** · 04-26-2020, 02:02 PM

its behind the race that the bearing rides in ???when bearing falls out the race must stay in case its bearing and race if race is falling out you have a situation?????

**TEXAS20225** · 04-26-2020, 02:04 PM

pull up exploded view on boats .net it is how they are built and in that order simple as pie or clear as mud ?

**TEXAS20225** · 04-26-2020, 02:12 PM

https://www.boats.net/catalog/mercur...2-1-gear-ratio this link to boats .net with view of guts stack on propshaft!!!! number 56 is bearing and race thats how they are sold race is installed in case with a special tool from merc or after market its usually pressed in and remove with slide hammer and special puller from merc

**TEXAS20225** · 04-26-2020, 02:14 PM

gear case work is simple but if you dont do your homework and understand what you study you will waste money and lots of it

**Aaronhl** · 04-26-2020, 08:47 PM

Originally Posted by TEXAS20225

pull up exploded view on boats .net it is how they are built and in that order simple as pie or clear as mud ?

Yes I've looked at the diagram many times... I have a regular 1647-9147-C lower unit, I don't need a slide hammer to remove the forward gear, I can remove it with my hand. After I remove the forward gear, do I need a slide hammer to remove another part to access the forward gear shim? Based on the parts diagram is shows the shim directly behind the forward gear bearing which is on the forward gear itself.

**TEXAS20225** · 04-28-2020, 10:38 AM

i did not say remove forward gear with slide hammer ????? I said race for forward gear its a two piece affair gear and bearing loose, race pressed into case shim behind it since its a tapered bearing race must be replaced with bearing and its sold that way

**TEXAS20225** · 04-28-2020, 10:40 AM

Again 1647 9147,1647 9147 c, 1647 1947 c1 all use same bearings seals shafts!!!!!! there are some changes but i wont cloud the water since its murky enough

**Aaronhl** · 04-28-2020, 12:56 PM

And thats why they call the thread lower unit school - so Texas how long does it take you to shim the lower units? With the forward gear shim behind the race, it seems like that process can take a while if you have to remove/reinstall it several times after measuring it. Same goes for the driveshaft shim