Rotary Cutter woods 990 - change gear box seal, easy or hard?

[coffeeman]

Earlier this month I checked gear box and out of gear oil. Since I'm one who preaches oil is cheaper than bearings, I can't believe I let this happen. I hope I haven't done some major damage to the guts inside the box. Time will tell. It doesn't seem to be making any strange noise. Now, about 6 hrs later, it doesn't seem to be leaking much. However, I suspect the seal on bottom will need replaced soon. How big is the job to replace?

Wondering.....Coffeeman

 

[rbargeron]

Hey coffeeman,

The bottom seal on the gearbox is not a huge job. Getting at it is where the work is. Once its apart, just pry out the old seal and tap in the new one with a suitable driver (I think I used a piece of plastic pipe).

Couple questions - is there oil puddled in the housing? Any other wet spots? Is the top vent area dry? Reason I ask is I'm wondering if it wasn't all that full in the first place. It doesn't take much oil to keep everything wet in there when it's spinning. But it sure doesn't want to be dry.

To change the seal:
(1) Take off the 2 top sheet metal covers and take the nut off the spring tensioner.
(2) Loosen or remove the belt - good time to remove, free up, and re-grease the tensioner/idler arm. Sometimes they are stuck.
(3) Unbolt the center deck cover and turn it up - no need to unbolt the gearbox from it.
(4) The big pulley has a split taper bushing - take out the 3 bolts then use them in the alternate tapped holes to push the bushing apart. Slide the pulley & bushing off the shaft.
(5) Dig the old seal out with a screwdriver
(6) Smooth the shaft with emery cloth to remove any roughness that may have been causing the seal to leak.
(7) Put in the new seal and put it all back together.
(8) Don't forget to put in some oil :thumbsup:

As always, prompt cheerful refund if info is bogus. Not responsible for effects of age, wear and tear, lack of maintenance, etc. - not to mention the condition of your RM990 mower !

 

[coffeeman]

Hey coffeeman,

The bottom seal on the gearbox is not a huge job. Getting at it is where the work is. Once its apart, just pry out the old seal and tap in the new one with a suitable driver (I think I used a piece of plastic pipe).

Couple questions - is there oil puddled in the housing? Any other wet spots? Is the top vent area dry? Reason I ask is I'm wondering if it wasn't all that full in the first place. It doesn't take much oil to keep everything wet in there when it's spinning. But it sure doesn't want to be dry.

To change the seal:
(1) Take off the 2 top sheet metal covers and take the nut off the spring tensioner.
(2) Loosen or remove the belt - good time to remove, free up, and re-grease the tensioner/idler arm. Sometimes they are stuck.
(3) Unbolt the center deck cover and turn it up - no need to unbolt the gearbox from it.
(4) The big pulley has a split taper bushing - take out the 3 bolts then use them in the alternate tapped holes to push the bushing apart. Slide the pulley & bushing off the shaft.
(5) Dig the old seal out with a screwdriver
(6) Smooth the shaft with emery cloth to remove any roughness that may have been causing the seal to leak.
(7) Put in the new seal and put it all back together.
(8) Don't forget to put in some oil :

Questions asked answered

no oil on deck of mower. Seems to be oil seeping through seam on front of deck. loose grass seems oil soaked.

Top vent is dry.

I couldn't see how much oil was left in gear box. However, from a distance I did hear the mower howlin' some. I would have checked oil right then, except, the belt is worn and slips in high grass. I thought the noise was the belt. Also my grandson was running the mower. I shoulda had him come in and checked oil. You know; shoulda, coulda woulda! After dry season starts I should get another season on belt. As is, seems to run ok so maybe there was a little oil in there.

Thanks for the reply.....Coffeeman

 

[rbargeron]

........Seems to be oil seeping through seam on front of deck............. the belt is worn and slips in high grass.............

The belt can slip if it gets oil on it (hard to clean). Currently I have a fresh 990 and an older one I found very cheap on Craigslist. It had a leaking gearbox seal and the belt was oil soaked. The seal was only a few dollars at the dealer. The belt lists around $140 but about half that if you start here. Go to the online catalog and type 18990 in the search box. Take care, Dick B