Chattering in out drive

[SSTKO81]

Post a serial number of its still legible. Pictures help too

If it's early 80's vintage you'll need either manual #3 or #6

 

[dubs283]

Serial number and photo would indicate an MC-1 style drive. Manual #3 should be the one with proper specs for assembly

#6 would have the same specs but would pertain to the R model drive. Basically MC-1 internals with alpha one style housings

If you wish to check further shimming specs you'll need special tools to do so

 

[SSTKO81]

Serial number and photo would indicate an MC-1 style drive. Manual #3 should be the one with proper specs for assembly

#6 would have the same specs but would pertain to the R model drive. Basically MC-1 internals with alpha one style housings

If you wish to check further shimming specs you'll need special tools to do so

I received the replacement NOS mercruiser cap and bearing set with shims last night. I came with good illustrations and specs for setting preload and assembly. -looks like quite a process but it’s a long weekend so I’ve got time. I’ll follow up

 

[SSTKO81]

Updated photos. Looks like the gears grenaded, most likely due to lower bearing failure. I’m gonna have to rebuild the whole stinking thing.

 

[dubs283]

Bummer

Not a simple task to rebuild the driveshaft housing. You need proprietary special tools for measuring gear height.

With that much damage to the gears there's likely pieces in the gear case assembly as well. You'll need to disassemble, clean and inspect the internals. Complete reseal if all is okay

Can't say for sure if an alpha one style drive (reliable aftermarket complete drives available reasonably priced) will install with no issues on the MC-1 bellhousing. Others here may know more about it

 

[Bondo]

Bummer
Can't say for sure if an alpha one style drive (reliable aftermarket complete drives available reasonably priced) will install with no issues on the MC-1 bellhousing. Others here may know more about it

Ayuh,..... Sure will,...... I'd go SEI.....

 

[SSTKO81]

I’ve opted to repair. Every bearing, seal and gear has been replaced. Preload is set and it will go back together today. A little oil and luck; we should be back on the water soon

 

[nola mike]

So curious as to what the total parts cost was, including tools?

 

[SSTKO81]

So curious as to what the total parts cost was, including tools?

I got out cheep. Just over 300 for everything including oil, seals, tools and all.

 

[nola mike]

I got out cheep. Just over 300 for everything including oil, seals, tools and all.

How did you manage that? Which gears needed replacing? No Merc special tools? Last I looked each gear set was multiple 100's...

 

[SSTKO81]

How did you manage that? Which gears needed replacing? No Merc special tools? Last I looked each gear set was multiple 100's...

I did a lot of part number cross referencing and found deals on eBay. This got all the gears, bearings, all the internals. I did have to take my bearings to a shop to have them pressed on, so I’m not counting that.
I actually put together a spreadsheet with Sierra # references if you’d like me to post it.

 

[nola mike]

I did a lot of part number cross referencing and found deals on eBay. This got all the gears, bearings, all the internals. I did have to take my bearings to a shop to have them pressed on, so I’m not counting that.
I actually put together a spreadsheet with Sierra # references if you’d like me to post it.

Definitely. How about the Merc tools? Did you do the gear housing as well?

 

[SSTKO81]

Definitely. How about the Merc tools? Did you do the gear housing as well?

Not, just top end

 

[ROY WILLIAMS]

Not, just top end

well the repaired it outdrive .... then run the boat ... the outdrive cap take it off and the water is inspected it .....
I was doing my outdrive 20 yrs , the O ring was water in the oil ,,, changed it ...inspected it of the top cap .... the outdrive is flushing the engine oil .....
then 48hrs draining ... then the gear oil outdrive ...

 

[Scott06]

Not, just top end

I was surprised how inexpensive the OEM gearsets are for your drive - Like $125 depending on ratio. I thought gear were more expensive than that

 

[SSTKO81]

I was surprised how inexpensive the OEM gearsets are for your drive - Like $125 depending on ratio. I thought gear were more expensive than that

View attachment 380775

You can really find great deals on them if you take the time to look around. I’ve got everything put back together now. I’ll pressure test the top and bottom individually, then the two halves back together. -hope to be back on the water by next week

 

[nola mike]

You can really find great deals on them if you take the time to look around. I’ve got everything put back together now. I’ll pressure test the top and bottom individually, then the two halves back together. -hope to be back on the water by next week

Great info, please post the details. Also, common wisdom is that your drive is going to grenade since you didn't rebuild the lower. Keep us updated...

 

[SSTKO81]

Great info, please post the details. Also, common wisdom is that your drive is going to grenade since you didn't rebuild the lower. Keep us updated...

That would figure BUT the whole lower was replaced about 8 years ago so maybe I’ll be okay for a while

 

[nola mike]

That would figure BUT the whole lower was replaced about 8 years ago so maybe I’ll be okay for a while

Thought is that the shavings from the upper contaminate the lower

 

[nola mike]

And tbh we don't get a lot of feedback from those that have just replaced the upper, so I'd love to hear a long term update