clacking in lower unit

[jsakat1]

Hearing a clack sound when shifting reverse; hear it a bit when forward. This sound is heard if I increase the throttle in reverse or foward, don't hear it when idle. It's not the sound it makes when shifting gears.

Drained the gearcase oil, it was black and inky as if it hadn't been changed in a while. Bought motor that way, and I should have checked before.

Any suggestions or predictions as to what it could be. I am taking to a mechanic this week.

[gcapehart]

Just did a lower fluid change using the Lucas stuff and ours is quieter and smoother. Black as you say indicates  abuse (report to SPCOB!). But try the Lucas. It is $5.00. Be sure to fill it with your motor vertical not in the trasit position(up and braced). Good luck, Gary

[jsakat1]

Thanks, But Lucas enough won't solve it. Taking her in on Wednesday to see about the lower unit, and the prognosis is not good? Looking for a cheap lower unit for an 85 Merc 75 HP 4-cylinder. If anyone can help...

[GoneFission]

Here are some ideas for a lower unit you could check out:

http://motors.shop.ebay.com/_Boat-Parts ... itQQ_fxdZ1  

Good luck!

[MarshMarlowe196]

Is this happening with your boat underway?  Or when you have it parked on the trailer (not in the water) ?

[jsakat1]

was happening when I had the engine. To update the story. I sold that motor. Bought a 90 Mercury. replaced the midsection with a 96 Mariner midsection in October. The powerhead looks good. Started it the other day, but it is leaking fuel mixture from the intake valve. Will post a new thread on that. The noise was out of water.

[MarshMarlowe196]

I guess it doesn't really matter now, but a clacking in the gearcase w/o the motor being in the water and engaged if forward or reverse is normal, usually.  With the extra load put on the driveshaft by the resistance of the water, the clacking goes away.  After I modified the pitch on my old propellor on my suzuki by driving it into a shallow concrete boat ramp, I thought I had fudged something up internally because I could hear that noise (of course you don't check for noises like that until you think you've broken something  :)  )  , but I was quickly reassured that the clacking is normal out of the water.  

Of course, it could have been something different altogether