Craftsman 18hp Rally Mower

Well I return again. I've been getting lazy with my updates so here comes another wave.

I've been wanting to ride this thing so I just did a quick inspection before and found some carnage.




The frame had cracked right behind the front axle on both sides. I wasn't expecting this because I don't run big tires or do a ton of wheelies but I do jump it sometimes and because of the stiff front tires it impacts hard. As you can see in the second pic I just welded the cracks then plated them with a piece of angle.

I went on a few mile ride on dirt roads near my house. It went well for the most part but my belt kept slipping past the keeper on one of the idlers so that was annoying but other then that it was fine until I turned it off at the shooting range to scope out a trail on foot.



It wouldn't start after that and I flooded it like a amateur. I waited 20 minutes and then it started after a couple pulls. It continues to be unpredictable rough starting. Not sure what is causing it but I'm gonna look into it. I'm considering upping the gearing alittle because more transport speed would be good.

One last thing. My transaxle was quite hot to the touch after the ride. Is this normal? I was going like 20mph for almost an hour straight.
Would venting it help?

Venting would help your seals. Are you running grease or oil? I can’t remember. But if you’re running grease, think about switching to oil. These transaxles will make quite a bit of heat, the more you can do to keep them cool and lubricated the longer they’ll last

I am currently running oil but the other thing is because of the live axle swap the keyway makes friction which could at to it. I figured the vent might. just help release some heat in there.

Yeah it’s possible, definitely worth relieving the pressure in there though

My 633 in the simplicity was pretty hot to the touch too after my longer ride last weekend. I couldn't keep my hand on it for a long time but could for a few seconds. I would think that is normal as there is a lot of friction with all the gears. I agree about using oil instead of grease for high speed use though. Probably does lubricate a lot better.

Not to jack the thread, but while we're on this subject... When switching to oil... Do you just use like, 10W-30 or something? I'm running 80W-90 gear oil in the MM so I don't think that counts.

Murraymountain wrote:

Not to jack the thread, but while we're on this subject... When switching to oil... Do you just use like, 10W-30 or something? I'm running 80W-90 gear oil in the MM so I don't think that counts.

It is best to use 80w-90 or something similar that is a gear oil. 10w-30 would work but it doesn't cling to the gears and climb as well. Some people use lighter oil or even ATF for cold weather applications because they would have shifting issues and resistance with heavy oils.

mr.modified wrote:

My 633 in the simplicity was pretty hot to the touch too after my longer ride last weekend. I couldn't keep my hand on it for a long time but could for a few seconds. I would think that is normal as there is a lot of friction with all the gears. I agree about using oil instead of grease for high speed use though. Probably does lubricate a lot better.

Well that makes me feel better because I was worried mine was getting to hot because of axle friction but old 633a have roller bearings for axles so it must just be from gear friction.

mowerjunkie03 wrote:

Murraymountain wrote:

Not to jack the thread, but while we're on this subject... When switching to oil... Do you just use like, 10W-30 or something? I'm running 80W-90 gear oil in the MM so I don't think that counts.

It is best to use 80w-90 or something similar that is a gear oil. 10w-30 would work but it doesn't cling to the gears and climb as well. Some people use lighter oil or even ATF for cold weather applications because they would have shifting issues and resistance with heavy oils.

So keep using 80W-90? That's the plan right now...

80/90 is good. Venting is a must with oil...if not it will build pressure and start leaking from the seals unless you run stock gearing.

"Rerun"]80/90 is good. Venting is a must with oil...if not it will build pressure and start leaking from the seals unless you run stock gearing.[/quote]

I just saw that you had vented your peerless on your thread. Thats what got me thinking about it. Thats smart that you used the fill hole on a MST. The problem is I am running a Spicer so I'm concerned about drilling though the thin case. I don't want it to crack. But it does build up pressure at high speed. It forces oil out of the case at the axle shafts and areas where the mating surfaces are thin. Do you know of any strong areas in the case where it is safe to drill and tap?

I haven’t tried to vent a Spicer myself. I do have 2 of them in some craftsman’s in my junk pile. I’m now curious myself....I’m sure someone has done it and can chime in.

The fill hole on my 820 was already tapped for a fitting. There aren’t any plugs of any kind on the spicers??

One not so great but workable option might be to drill a hole a bit smaller than a 3/16 size clear fuel hose and then just push the hose through the hole a bit for a vent. On string trimmer gas tanks, that's all that holds the fuel line in place. Then it would work even in a relatively thin spot on the case. If you want to chamfer the edges a bit, just use a larger size drill bit and touch it to the hole for a second with the drill.

Of course it might be good to have the case apart and all that when you drill it so the shavings don't fall in. Later on you could always block the hole with either permatex or a bolt and permatex. Could spot weld the nut on once you tightened it to make it permanent.