repainting/reassembling lower drive units
 

2 part question

Service manual says the large bearing carrier retainer nut gets torqued to 150 ft #. IS THAT RIGHT? Seems like a whole lotta torqe on alumiinum.

As far as repainting. Does Merc paint before or after the lower unit is assembled? Some of the internal housing areas are bare, no paint. Doesn't that allow for corrosion?

As always,
Thanks

due to the diameter of the nut 150 is not that much. However, that spec would only be used when using the solid shims, if using the load ring the nut is tightened until the preload is to spec.

Marc
I have a service manual from '94. The info on the B1 only showed solid shims. But the B2 did have the load ring. Guess they changed the B1 at some point.
Just checked my original parts from my '99 drives. I have the load ring. Does the 5-8 lb. in (used) bearing preload from the '94 B2's apply to my '99 B1's also?

My plan has been to reassemble the lowers just as they came apart. I did not remove any of the pressed in bearing races and any shims behind them. Nor did I dissassemble the shafts assemblies. Kept it as basic as possible. My thoughts have been if reassembled just like they came apart, I should be ok as far as all the clearances and backlash as the gears and bearings all look good. I do have new verticle shaft pinion nuts per the instructions.

Also, what is 'Special lube 101' spec'd out for the retainer nut threads? Available at auto parts stores or an exclusive Merc item?
Thanks for the heads up.

Jerry

Jerry, you should be OK, Used bearing spec should be the same. If you don't change any components you should not have to re-shim.

I just had lower unit powder coated satin silver .It looks awesome and the coating is real strong. Since you went through so much work to blast the lower I'd have it powder coated. My upper is beening done right now in black.

If you powder coat, you still need to paint the housing threads and carrier nuts after assembly.

I've investigated getting my drives powdercoated. The problem is any dings, nicks, or corrosion will ruin the finish and you're back to square one. Here's a cut-n-paste from a write-up about powdercoating.

(BTW - I'm having to strip an entire swim platform right now because of this.)

"Once you have your precious parts powder coated, you will never be able to have repairs (chips, scratches, etc.) redone in powder, without tanking it apart, stripping and recoating. You can have a small touch up kit made by your local automotive paint supplier "made to match" as close as possible. Remember, special effect powders will not be able to be duplicated! To make life easier, I suggest having a 3"x5" or 4"x6" "Q" panel as they are called in the trade, or flat piece of metal coated at the same time as your parts. . Have the coater write the powder manufacturers company name, part number and color name on the panel for future reference, (i.e. Morton, #PS2230, Ruby Red). Save this panel! Take it to an automotive paint tinter for a touch up kit. Many of them use color computers today and this is the easiest way to get the match. "

Now THAT is the reason for asking if they are painted before or after assembly. What about the nut and housing threads!

So I should assemble the unit then paint? The nut nor housing threads were painted when I disassembled it. Just the 1/2" area before the threads. By painting afterwards, I'm just basically sealing the outside joint, doing nothing for the threads themselves.


If painted before assembly, won't that prevent the nut from screwing on because of the paint buildup?

While this is seems petty, I want to do it the correct way. How does a new lower unit housing come when ordered?

Don't want to powdercoat cause I don't want to remove the races. Not to mention I just ordered the paint, primer and al prep for a mere $165.
Plus if by some outside chance the boat falls off the trailer going down the highway and the drives get scratched, be much easier to touch up painted drives.

Thanks!

If you've gone through the trouble of stripping them, blasting them...then buy a can of ALL METAL, fill and fair the chips and pits, and then paint them up. They will look NEW...I promise. I just did my TRS drives with this stuff and then got good primer and paint for around the same money-they came out AWESOME!!! The ALL METAL is a metal based filler that is specifically made for filling this stuff, it seals up what you fill, will not fall off or shrink. As far as assembling them or not, your on the right track as far as paint them after. Less edges to chip/scratch and no threads to clean. The special lube for the nut is used to prevent corrosion between the steel and aluminum, which expands and splits the lower case around the ring. Use it, as these cracks form FAST and once there there. its new lower cases for you, or at least 800.00 for a temp repair.

After I got the lower housing back from powder coating I re-chased the cover nut threads with a new cover nut merc#79448 and 101 lube. The race areas I had to sand a little. I did notice that it didn't scratch as easy the merc finish in the drive stand. We send everthing to the powder coater like tuna towers, boat hardware, and engine parts and so far so good. Everyone seems to like it. Salt washes off with a garden hose.