How do you check out a lower unit?

[ronward]

This question is not specific to any application. I see a lot of ads for outboards that need a lower unit or for lower units by themselves. I was just wondering how you would check out a used lower unit to ensure you're getting a good one. Is it as simple as it not leaking and the driveshaft turns the prop forward and reverse?

 

[Faztbullet]

Re: How do you check out a lower unit?

Number #1 red flag in my book fresh oil. The overall condition of casting(beat/banged/broken) will give you idea of usage as will spline wear. I look at buying a used unit as a crap shoot if its from a everyday joe but a dealer that has one would be a better choice. I myself warranty a used unit 30 days as I will go thru it and check/repair it.

 

[HighTrim]

Re: How do you check out a lower unit?

You could pressure test it to determine if it leaks. No way to tell the condition of the gears, bearings, and such, and those are the expensive items. As stated, treat it as an as is purchase.

 

[Silvertip]

Re: How do you check out a lower unit?

The above comments a very valid but a simple basic check is to pull the drain plug and see what comes out. Nice fresh oil = good thing but is no guarantee the unit is fully functional. It just means the seller replaced the lube. Tan, milk shake looking lub or water says seal leaks. With the unit in neutral and engine off, spin the prop by hand. Roughness says bad bearings. If you have the opportunity for an on water test and a jerkiness at higher throttle settings is noticed the clutch dogs are worn and jumping. It could however be as simple as shift cables or shift mechanism misadjustment.

 

[V153]

Re: How do you check out a lower unit?

Yup. Check oil & pressure test.

If you can't test it running. Make sure you at least spin it manually. See if it'll shift, check condition of water pump, etc.

I been purty lucky with gearcases but I did get burned once. Well not zacly burned, stupid's more like it.

I thought I was gettin a great deal on a '93 140 lower, and I did. $100 bucks cash!? Checked out okay, oil looked great, no shavings on the magnet. Took her home, cleaned her up a bit. Went to stick it on the motor & discovered it was a longshaft! Never noticed? Duhhh ...

 

[ronward]

Re: How do you check out a lower unit?

Yup. Check oil & pressure test.

If you can't test it running. Make sure you at least spin it manually. See if it'll shift, check condition of water pump, etc.

I been purty lucky with gearcases but I did get burned once. Well not zacly burned, stupid's more like it.

I thought I was gettin a great deal on a '93 140 lower, and I did. $100 bucks cash!? Checked out okay, oil looked great, no shavings on the magnet. Took her home, cleaned her up a bit. Went to stick it on the motor & discovered it was a longshaft! Never noticed? Duhhh ...

Too funny. Thanks for all the replies guys. Pretty much what I was thinkin I've been lookin at several motors, all seem to have some issue or another. Was just trying to find out if there was any real telltale of a bad lower unit. I guess just as with a vehicle tranny, you can hide some problems. Seems like the worst sign might be brand new oil.