2 outdrives in 20 hours PLEASE HELP

[larrythorson]

I have a 1986 Celebrity 190 with a 305 Chevy with a OMC Cobra that has a total of 320 hours. It was 13 hours on a total rebuild the front seal either had pressure build up behind it, or seal failure dumping the gear lube into the bellow, dropped the case to where the oil was just covering 1/2 of the gears in the upper case. I removed the unit and returned it to Southern Michigan to the outfit who originally rebuilt it after I struck struck something with the OEM outdrive. They pulled it apart and "rebuilt" it and returned it after supposedly changing the upper vertical output shaft and the shims under the preloader and returned it to me. I again installed the unit and i had a total of 30 minutes run time 20 of which was at less than the spedo would register and never more than 1/2 throttle. I didnt see any initial problems and all seemed fine until I pulled the dipstick plug after returning home and found 1 drop of blackened Volvo Synthetic on the stick repeated again and nothing on the stick!!!!! Pulled gear case cap and again only half of the upper gear set was covered and the rest went out the seal into the bellow. I returned the unit as it is under warranty and the owner is now saying its because its overheating because there is a circulation problem with my fresh water open system. I removed the inlet to the cooler and ran my engine for 15 minutes and after about 5-7 minutes the temp came up to a rock steady 160*F and never went any higher and the water coming thru the transom was warm but tolereable to the touch. I then pushed water back out the transom thru the intake port and no obstructions anywhere. can someone please help me I am not a rich man and this was supposed to be for the family to enjoy and its turned into heartache for us

 

[larrythorson]

I also should add that both times the oil was scorched black, The oil was changed at 10 hours following the instructions of the rebuilder. The first time it dumped and scorched the oil was 3 hours after its first change and a 1/2 hour of run time on there 2nd rebuild again scorching the oil black and dumping the upper into the billow. The proper OMC fill procedure was followed both times.

 

[Howard Sterndrive]

ok, cooling of the drive is "assisted" by sea water enroute to the engine, but the Cobra drive can survive just fine for decades without any water flowing through it.
If you had a seawater issue, your engine would overheat long before the drive suffered any related issues.

Sounds like they aren't assembling the drive properly with regards to shimming and/or seals. Failure analysis over the internet is usually supposition and educated guesses, but there's mine.

There's no "preloader". Proper preload of tapered roller bearings is accomplished with shims at assembly.

 

[alldodge]

Not a OMC guy but agree with Howard, a correctly assembled drive will last a very long time with simple yearly maintenance. Don't see any way one just re-assembled would be damaged unless something was not done correctly during assembly

 

[larrythorson]

As I dove head first into this and what in my opinion would happen even if there was a complete water pump failure on the block and the thermostat stuck closed is that water being picked up from the drive and being pushed forward would circulate right back out the exhaust manifolds as I have seen pics of the water pump housing and it isnt partitioned off in any mannner. I also should add I am a chemical process tech and control room operator in a plant where we have many exchangers,coolers and boilers and i dont buy the line of BS that a 1 inch passage under the corner of that case provides that much thermal transfer when in reality it only has a half inch of surface area for 8-10inches.

 

[larrythorson]

I meant thermostat housing, not water pump.

 

[larrythorson]

A new question as I have talked to several OMC Mechanics and there seems to be a discrepancy as how to fill the case anyone care to help???

 

[alldodge]

For the cobra I found this
http://www.crowleymarine.com/support/tech_articles/omc-cobra-outdrive-lubricant-filling.html

 

[bruceb58]

If you don't fill from the middle screw, you will not fill your driver properly. How do you fill your drive?

 

[Howard Sterndrive]

from the middle

 

[bruceb58]

 

[larrythorson]

Bruce is that right out of the OMC manual???

 

[bruceb58]

Yes...OEM manual