Changing Tranny oil on Coronet 12.5hp hydro

[apbling]

Hi All,

I would like to change the oil on my mid 90's Coronet 12.5 HP hyrdo (its got the Kohler motor if that matters).  I can't seem to find any info on how to do it, can someone give me a hand?

Also, it seems like it doesn't travel at the same rate of speed at full speed anymore either - Maybe its just me, but it seems a hair slower.  Now, it is an older mower with plenty of carefree miles on it, but it runs like a top and has had no other issues whatsoever, so I was wondering if maybe there is an adjustment on the linkage to the speed control lever and maybe its got some play in in now with age...

Also, is there a maintenance manual available online that someone is aware of?  The operating manual doesn't get too deep into routine maintenance.

[apbling]

So, I think I may have figured this out - From the part diagrams, there is a breather, but no drain - then I find in the specs area of the owners manual that it takes 20w-50, but no capacity and says "note - transmission is a sealed unit"  -  I'm guessing that means that its not intended to be changed??  I'm not sure 20 year old oil in my tranny sits well with me... but does this sound correct?

[GregB]

In a world of planned obsolecence unfortunately YUP.

 

Maybe some one else will chime in, if they have tried it before. 

Most of the focus here is large frame garden tractors, but on occasion some posts on the coronet line.

 

Breather could be used as a fill point , but you would some how have to drain the case.  And measure the amount of fluid you took out for replacement.

Most hydros have and ideal fill point to little or to much causes problems.

 

 

[apbling]

Thanks Greg - I was thinking of trying to use the breather as well - I have one of those two hose handpump deals - was thinking of sucking out what I could and measuring it and replacing the same amount - Should be pretty accurate because the tranny has never leaked, so I would assume whats in there is darn close to what should be.  I know I won't be able to get it all out, but I'm thinking if I get 3/4 of it, its better than using 20 year old oil...which probably has the consistency of water by now.  Local repair shop told me the same story - but he said the oil was good for 1000 hrs or so.  So, in WI we only cut lawn from May to Oct.  Thats 6 mo, call it once per week for 2 hrs.  48hrs a year.  I think my folks bought it in 1995, so thats 576 hours, and based on the info I got its only 1/2 through its life.....but I'm guessing its good for 1000 hr or a decade, whichever comes first hahaha.

Only major issue I foresee with doing this is its a rear engine rider, but I believe the breather isn't directly below the motor - but the engine bay is almost like a box with no lid.  I'd have to drill a hole through the floor of the box to access it.  Since I'm not plowing a field or taking the mower off-road baja racing it'll be ok with a small hole there... would be no different I'd think than the hole for the vertical crank form the motor to drop through....