Can I flush my gearbox

[tassie ben]

1979 Johnson 6hp seahorse 6r79e

Hi to all and "great site iboats!!!"

I recently became a first time boat owner, i picked up a purdon 12ft fibreglass dinghy in reasonable condition and along with it came the motor that was reported to work but had a cooling problem, chucked in for free basically. And so began the journey of resurrection. To cut the long story short, the motor worked but yes there was no water through the pee hole. Taking the motor apart i found that the bottom half of the water pump (housing and retainer assembly) was heavily corroded although water had not penetrated the gearcase as such.. so determined, i tracked a part in the U.S. as they are obsolete here in australia and every second hand one was corroded also.
To remove this part from the main lower unit i had to "butcher" it. this has resulted in an intact lower unit..thank goodness...but some small foreign bits of material have no doubt entered the gear assembly.

QUESTION: Can i, and if so what with, flush the gearbox to try to remove anything inside...is fuel ok?? or will it damage seals.

QUESTION: is it fairly straight forward to split gearcase to inspect for foreign material?

Some of you will say purchase manual but i can't seem to find one for under $150 aussie dollars (which comes from the U.S. and is two parts out of three postage)

Any help most appreciated,

 

[JoLin]

Re: Can I flush my gearbox

Don't see any reason you can't try flushing it to remove any foreign matter. It can't hurt anything. Just on general principles I would stay away from fuel. I wouldn't use it in an automobile transmission, either

Why not just try a thin, light duty oil-I think any oil would do simply for flushing purposes. Use something cheap. Flush it as many times as you think appropriate, then let it all drain out well. Do a final flush with proper gear lube and refill with the correct stuff, too.

Anyway, that's how I'd approach it.

 

[tassie ben]

Re: Can I flush my gearbox

thanks jolin,
i was hoping that the answer would be something a little less viscous, so i could swish it around a little more...if not fuel do you think methylated spirits or turps? otherwise i'll go the oil.

 

[wilde1j]

Re: Can I flush my gearbox

I've used kerosene and mineral spirits with no ill effect. Just make sure to get all out using compressed air after draining and leaving open to drain for a while. You don't want to thin the correct gear oil.

 

[tassie ben]

Re: Can I flush my gearbox

Hi jim,

Thanks so much, thats the answer i wanted and i'll be off to do it shortly. As i have the leg off already and lower water pump housing off too then the gear case is open to the air etc. and i shouldn't have too much trouble draining and air drying..i am from australia so i am assuming mineral spirits in your lingo is mineral turpentine in ours.
Thanks again for the reply, very much appreciated..

ben from tassie (tasmania thats where the little devil is from)

 

[wilde1j]

Re: Can I flush my gearbox

Sure, BTW, don't run the motor in gear with load on it. Just run for a while, shift a few times, stop and drain.

 

[tassie ben]

Re: Can I flush my gearbox

i wont be running it jim, the whole lower end is on the floor of the shed, disconnected from motor. I am just going to pour the turps in the top and swish it around and probably pour it back out the top (turning unit upside down). i'll then probably repeat process and drain out the proper drain hole?
then hopefully it is ready for when my expensive part from US arrives, hopefully end of next week if i am lucky

ben

 

[tassie ben]

Re: Can I flush my gearbox

ok....i have flushed the gearcase and some crud came out, all small apart from a piece the size of a match head (some of the alloy i was worried i dropped in there from the butchering of the pump housing and retainer assembly..see first post).

Question: i think i can hear a little more in there..do i seperate the gearcase to inspect?
i have the two seals being posted just incase. is it hard to replace gear set?
and lastly do i need to remove the skeg screw to seperate the halves?

thanks for any help

 

[ezeke]

Re: Can I flush my gearbox

To remove the skeg, you will need to remove the phillips head screw.

That screw is the fulcrom for the shift, so don't take it out unless you are ready to proceed with the disassembly.

 

[tassie ben]

Re: Can I flush my gearbox

thankyou ezeke,

do i need to take this out at all? if i am just inspecting for foreign matter?
if i do need to take it out do i do it after the halves are seperated or before?
i have no manual, i would love to take up online subscription to seloc or something but cant find it cheap enough (still around $150 aussie dollars- which includes a hard copy sent to my address).

thanks again for help

 

[tassie ben]

Re: Can I flush my gearbox

ok no more replies needed, i have found a manual near me locally, at half the cost of $79 (wow) and...i have decided on advice not to dismantle my gearbox as it sounds like trouble. I have flushed it pretty well and will take the chance of running it first when it is all back together. I'll then drop the oil out after first use and inspect then i'll replace...thanks again all who replied to this post.
ben