New motor installed, after 30 mins drive locked up on water-towed in

[CamaroMan]

Put a replacement motor in last week.. 4.3 vortec- after putting in gimbal bearing slid in another yoke to see if it was smooth-went in deep and pulled out quite easy without issue.

Put drive on and ran a while on muffs while setting up motor, checking alot of things. Once on the water I noticed every time I put the drive in fwd/rev it would make a whining noise.. in neutral it ran perfectly - passed psi test, new oil up to dipstick.. motor hardly ran above 130 degrees..

After 2nd run cruising just on plane the drive locked up. Previously I could turn it by hand very easy - the motor shut down and we got towed back..

Started draining drive oil expecting to see bits of metal but nothing, perfectly clean. Took drive off, motor ran perfectly again (huge relief).

This boat was bough off ebay for nickles and the motor was completely and utterly seized. Rest seemed ok - Ill be opening the drive later today but just thought id see if anyone had any ideas as to what could have caused this?

The uper gears never made a squeak and it ran fine for about 2 hours on hose, till we put her in the water.

Im suspecting something in the lower unit-

92 4-winns with OMC cobra drive -

thanks!

 

[jimbo_jwc]

Pull the top bearing cap on the lower unit and inspect the taper roller bearing .

 

[CamaroMan]

Heading down now to have a look. Wouldnt the upper whine even in neutral though? it ran quite a while out of gear just fine.. :0 - just curious

Pull the top bearing cap on the lower unit and inspect the taper roller bearing .

 

[GA_Boater]

Load vs no load. Neutral has no load other than the water pump.

 

[Idlespeedonly]

I imagine when you pull the top cap off you will see the problem.
Most likely caused from improper filling of the gear oil.

 

[CamaroMan]

Well its possible I mucked it up - I filled oil thru the top with screw removed till it was above the mark on the little dipstick bolt, but all it took was 32 ounces after draining it for 30 mins..

So It must have settled and run dry? id i just toast an omc drive due to idiocy? I read everywhere 64oz is the quantity +-.. this thing stood for about 10 years.. I thought perhaps the bearings had formed rust maybe..

The upper bearing had a blue tint to it and there was an odor of burn in there.. like it had no lubrication :0 .. Ive ruined it.. 32 is half of 64 and im a dunce. Sometimes u learn the hard way :/

I imagine when you pull the top cap off you will see the problem.
Most likely caused from improper filling of the gear oil.

 

[Redrig]

Look at the bright side , now you have a reason to get an SEI outdrive to run with the new engine

 

[bruceb58]

Well its possible I mucked it up - I filled oil thru the top with screw removed till it was above the mark on the little dipstick bolt, but all it took was 32 ounces after draining it for 30 mins..

Yep..that was the problem...you fill it through the middle screw until it comes out the top.

 

[Scott Danforth]

if you read enough posts on cobra drives, you realize your not the first one that did not fill the drive properly and toasted it.

 

[Lou C]

Look at the bright side , now you have a reason to get an SEI outdrive to run with the new engine

Ahh I would not be celebrating that. No way can an SEI compare to a properly built and maintained Cobra. Mine's 30 years old, used in salt for 15+ years and only needed a few repairs. Crowley Marine and others sell rebuilt Cobra drives.

As far as filling it.....
JUST READ THE MANUAL!!!!!

 

[Lou C]

and PS if you filled an SEI or Alpha that way guess what would happen? Same!