Overfilling gearbox

[single]

Will i damage the PRM 120 gearbox if its over filled for a short time?

 

[cimo]

for a short time - highly unlikely to cause immediate failure.
the fact that its overfilled, would prompt me to drain the excess at my earliest convience though.

 

[cryan]

It very much depends on how much you have overfilled? If your a gnats a**e over the high level then, no it won't do much damage. If your and inch over high level then you may very well do some damage.

 

[single]

Mmmmmm- its about the same depth again as dip stick min to max!

 

[cryan]

Then I would stick a syringe in and suck some back out. It will be easier and cheaper in the long run.

 

[myquest]

You have to consider the "damage" that may be occurring. Too much oil in a metal box of metal bits whizzing round isn't going to make it "fail". The bits you will be putting a strain on that they were not designed for are the seals. But will they fail catastrophically if a little too much oil is put in? They might weep, but fail??? Do as Cryan has said and bring back to correct level in the near future.

 

[macd]

As said, the principle danger with a conventional cone clutch box such as the 120 is of damage to seals due to the air gap being smaller and thus internal working pressure becoming higher. However, I believe the 120 dip stick incorporates a vent to atmosphere, so the risk is probably low...which is no reason not to get it right. If nothing else, it might forestall the box blathering oil into the bilge.

Note that a few years ago PRM changed the oil spec for their cone clutch boxes from "whatever the engine is using" to ATF.

 

[tcm]

The main damage possible from overfilling is to the shaft seals. Some gbox oil will leak out if/when there's a problem, altho yerknow, it's not ultra serious - simple yotitie gearbox is splash lubnricated, so as long as there some gbox oil in there, nae problem. If a bit leaks out, you can put some more in, not a huge deal. If the gbox goes milky then the lower/outer seals have failed, and you can try sucking the oil out and replacing altho obvious better is to replace the seals at the next earliest liftout. Some manufacturers have in the past recommended too much oil in the gearbox (eg Yanmar on the 4JE made dipsticks too short) and then told dealers that oops, they're a bit overfilled. I'd keep the gbox oil as low as possible, not at the high end of the dipstick.