can you use marvel mystery oil in your transmission to stop leaks?  Or will it hurt the transmission?

shiner620 - 07 June 2010 10:49 PM

can you use marvel mystery oil in your transmission to stop leaks?  Or will it hurt the transmission?

MMO, used in the proper dosages, will not hurt your transmission. As for stopping leaks, I don’t think so, but you’ll have to ask Rich.

Marvel Mystery Oil does contain an additive that helps condition seals and also has some seal swelling characteristics.  I would try adding 16 ounces of Marvel Mystery Oil to the transmission to see if it stops the leak.  It is completely compatible with the automatic transmission.  If this does not, work try adding 15 ounces of CD-2 Heavy Duty Engine Oil Stop Leak, Stock No. 4105.  This product is designed to swell seals in the engine oil but is also safe to use in automatic transmissions.

I have used it before on transmissions and it works great, makes them shift smother

Are there any more anecdotes to this? The thought of putting a mystery oil into a $1500 transmission absolutely makes me cringe.

-Techniker

curious how often the mmo can be added to the trans?  Added some a couple months ago, without any hitch thus far.....if I were to get low....Could I use more?  Or just go with the recommended fluid per the vehicle manufacturer?

I have/had a slight weeping seal on the transmission and the trans fluid level seems to be consitent now....have not had to add any since adding the 16 oz. “top off” of MMO So crossing my fingers there.....