Rear Finish Mower bought used JD 272 finish mower; gear box seems to leak

botemout · May 29, 2011

Hi all,

It's been some time since I posted anything (have been largely problem free - knock on wood!). I recently bought a JD 272. When I got it home I noticed that the gear box needed oil; I filled it and cut my lawn (in a record 45 mins - what a time saver!). Today I went out to hook it back on the tractor, checked the oil and it seems as dry as when I first got it home. The ground also has some oil on it.

I'll clean it tomorrow (after the using it) and put some newspaper under it to confirm that it's leaking significantly (how could it not be), but I expect that I'm in for a rebuild.

Question(s):
- is a gear box rebuild hard to do? (Or, even, possible)?
- I'll call my local tractor store on Tuesday and ask whether they have kits (gaskets, I'd think - what else could there be?)
- Anything else I need to keep in mind (gotchas)?

Also, what do you all think about the 272? It's probably a little big for my yard (about 2-3 acres, though LOTS of obstacles that makes mowing slower than it'd otherwise be), but I sure like it on the straightaways.

Thanks for any info,
JR

Wolfy · May 30, 2011

I have a JD 261, which is a little older and smaller than a 272. About 10 years ago I had a leaky gear box. I brought to a JD dealer, they fixed it, and it hasn't lost any oil since. I want to say it cost like $200. The mower itself has been a complete joy to use. A few idler springs have went, but otherwise very happy with it. As long as your tractor handles your 272, you shouldn't have any trouble.

botemout · May 30, 2011

Wolfy said:
I have a JD 261, which is a little older and smaller than a 272. About 10 years ago I had a leaky gear box. I brought to a JD dealer, they fixed it, and it hasn't lost any oil since. I want to say it cost like $200. The mower itself has been a complete joy to use. A few idler springs have went, but otherwise very happy with it. As long as your tractor handles your 272, you shouldn't have any trouble.

Thanks, Wolfy.

Can anyone else chime with an answer as to how hard it is to rebuild a gearbox?

melvyn · May 16, 2012

I had the same experience, possibly the nature of the beast.
The best way to do it yourself is to have a shop manual on it, but the gearbox work is really not that difficult: just be sure to note where the various capscrews are located on the covers, as I recall some are slightly different lengths. Internally, there are two Timken tapered roller bearings and cups opposing each other on opposite ends of the shaft.
Important note: There are shims behind the cups which determine the shaft end play and gear tooth engagement > note how many shims are on each end and tag them as to location for reassembly <
As to the seal: do not use a standard buna/nitrile grease or oil seal lip when replacing this, unless you want to do this routine again in a few years. The standard lip material will stand up to petroleum products - but NOT to gear lube with EP [extreme pressure] additives which you should be using in a hard working gearbox such as this. You should opt for VITON seal lip material; which has excellent chemical resistance and is good -40F to 390F temperature range plus has excellent abrasion resistance. The standard buna/nitrile material has a temp range of -40F to 210F. When you are mowing on a 95F day, the VITON gives you a much greater safety factor.
> Important: check the shaft surface where the seal lip rides. If your fingernail catches in a groove worn by the seal lip, use a SPEEDI SLEEVE to renew the shaft surface. It might cost you $35.00, but it is less expensive than a new shaft, and will prevent leakage, which vertical output shaft reducers are prone to. The Timken bearings used in the gearbox are the same as are used on light utility trailers and should be fairly inexpensive at auto parts or farm supply dealers. As to gaskets, unless they are a steel shim spacer, you can use Permatex or Loctite #2 non-hardening gasket maker. If you have a steel shim gasket, "butter" both sides of the steel when assembling.
Take your time, and write down the procedure that you used, so you'll have a record for any future maintenance.
Enjoy the pride that you did it yourself !

easygo · May 16, 2012

I have a mower made by another manufacturer but it had the same issue. The possible problem is that the seal around the vertical shaft is faulty. The horizontal shaft is the one driven by the PTO and the vertical drives the pulleys. I bough the seal for $30 or so, and spent an afternoon getting to know know my mowing deck gearbox. Luckily he shafts did not have to come out. It was bit tough with few parts diagrams. That was two years ago and no leaks since.