Trencher Motor Replacement

[BobRip]

After trenching around a good size stump, I noticed that oil was leaking around the shaft. I had noticed earlier that a small tree has gotten up around the shaft seal. I suspect that this damaged the seal. I lost about 2 quarts of oil.

To replace the motor I found that I have to get a special socket from Power Trac. They "loaned" it to me. I gave them a credit card number and they shipped it to me. After use I mailed it back and hopefully they will credit my acount.
The socket is designed to go into the hollow of the drive sprocket shaft and loosen a castellation nut. See attached picture.

Bob Rip

 

[BobRip]

I used a gear puller to get the sprocket off.
To put the chain back on I called a neighbor. The chain seemed to weight about 100 pounds (no I did not weight it), so I fiqured I would need help. It also takes about 4 hands to hold the chain and put the bolts and brackets back on. We got it back on and realized it was backwards, so we had to take it off again. No big deal, but it was nice to have help. (I did dig about 200 feet of trench for the neighbor a few years back and this is the same guy I pulled a gate post out for.) I doubt that I could have done this alone, so many thanks to Pete.

One thing I should have done is put some grease between the front idler socket and the bolt going through it. I will probable try to spray some grease in there.

To adjust the chain tension, you put the trencher bar horizontal and adjust the tension (or slack actually) until the gap between the bottom of the bar and the top of the chain is about the width of 4 fingers on your hand (for me that's about 3 1/4 inches). I am told by Power Trac, that this gives the correct tension. It seems to work fine.

Attached is a picture of the trencher with the chain removed.

Bob Rip

 

[BobRip]

Actually, as I now remember, the hardest part was pulling the socket out after I retighted the nut. I think the socket was not machined perfectly, and I had to pound it in a little bit on initial nut removal. I ended up loosening it up, spraying it with some PB Blaster, and then putting it back in rotated to another position.

My best advice is do not let vines or anything else get caught in the seal of a hydraulic motor shaft. I had earlier got a tow strap caught in the stump grinder motor and had to have it rebuilt.

The rebuild price which included a bearing and seal replacement was less than $80, plus shipping back and forth and shipping the socket back and forth.

I figure my trencher has about 1500 feet of trench on it. It is rated at 5000 feet.

Bob Rip

 

[MossRoad]

That socket looks like a hydraulic motor coupling with the shaft hole machined out to fit a square drive.

 

[BobRip]

Actaully it fits a castellation nut. I think they did take a regular socket and machine it.

Bob Rip

 

[BobRip]

Oh, I understand now. Maybe your right.

Bob Rip

 

[MossRoad]

Nah, I guess I'm mistaken. I thought my coupling on the shaft for the brush hog had 6 tangs, but each half only had three tangs and the rubber spacer between them has 6 tangs. Here's a link to one at Northern tool that is similar to the one on my brush hog.

 

[BobRip]

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To replace the motor I found that I have to get a special socket from Power Trac. They "loaned" it to me. I gave them a credit card number and they shipped it to me. After use I mailed it back and hopefully they will credit my acount.
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The good news is that PT did credit my account for the returned socket.

Bob Rip

 

[BobRip]

I took the PT over to a friend's house today and trenched about 150 feet of trench in two hours. The worse problems were getting rocks stuck in the trencher. This happened about three times. I always carry a hammer and chisel and it takes about a minute or two to knock a rock out.

My friend had prevously thought of the PT422 as a riding mower, now he talks about buying one just for the trencher. I doubt that he will, but he understands better what at PT can do.

Bob Rip

 

[stray]

How did the trencher do cutting through roots. Say 1 to 3 inches in diameter. I have a job coming up. 180 ft through a wooded area, 3 ft deep. I have the mini hoe but no trencher. any recommendations?

 

[BobRip]

I did not have trouble with roots here. At another neighbor's house we ran into some 2X4 that were buried during the recent house construction. The trencher just keeps bouncing on these. It does tear then up, but it takes too long. We pulled it out by hand. On other digs I have found that one inch roots are easy, two inch OK, 3 inch can be a problem. I then get the stump grinder out. It goes through roots pretty fast. Do you have a stump grinder? It it good for breaking up the soil and cuts roots near the surface.

I have not had any issues with roots on the minihoe yet. You can curl the bucket and that does pretty well, but I don't have a lot of experience with it. Clint Blake dug a 20 foot long trench about 4 feet deep in roughly 30 minutes with my minihoe. He was very impressed and this was his first real use. He was so impressed that he bought his own a few weeks later. I think your 180 feet will go pretty fast.

I have a digging bar (six foot long, 1 inch diameter bar with a chisel on the end). It is very good for cutting roots. I have not used mine since I got the PT. If you get desperate this will help.

Bob Rip

 

[BobRip]

I had another trencher problem last week end. The nut holding the drive sprocket on came loose and the sprocket moved out about an inch. Upon inspection the drive sprocket had a crack in the keyway and the inside was distorted. The keyway on the motor shaft was damaged. I filed it down to take out the lip of metal generated. I ended up buying a new sprocket and the special socket. This time the socket was loose on the nut and was easy to remove after tightening. I used the impact wrench and then torqued to 100 pounds (PT had no spec on this torque). I also used red locktight on the nut. I just hoped that the damaged keyway will not fail soon.
When this kind of failure occurs I always feel kind of stupid, knowing that I must have done something wrong. On the other hand if the first special socket had fit right and I had some instructions about using locktite it might not have been a problem. Total cost this time was about $156 dollars.
On the other hand, what's the point in owning the attachment if you don't use it. And anything that looks like a chain saw and operates in dirt, rocks, and roots will wear out.

 

[BobRip]

I took two pictures of the sprocket. You can see the crack in the keyway and perhaps the distortion in the hole. The sprocket was about $90.

 

[BobRip]

Power Trac send me a new castellation nut with the sprocket. It fits the special socket a whole lot better than the old nut(it's loose). This makes installation of the sprocket very easy.

 

[bjustice]

Re: Trencher Motor Replacement I know this is an old thread, but

After trenching around a good size stump, I noticed that oil was leaking around the shaft. I had noticed earlier that a small tree has gotten up around the shaft seal. I suspect that this damaged the seal. I lost about 2 quarts of oil.

To replace the motor I found that I have to get a special socket from Power Trac. They "loaned" it to me. I gave them a credit card number and they shipped it to me. After use I mailed it back and hopefully they will credit my acount.
The socket is designed to go into the hollow of the drive sprocket shaft and loosen a castellation nut. See attached picture.

Bob Rip

Old thread, I know--but does anyone know the hydraulic motor model number? I would like to purchase seals, etc. Any additional info on wrench, etc. Do I have to go back to Tazwell for everything? Also anyone know if TractorTaylorNut was successful in identifying and purchaseing sprokets and chain From aftermarket sources? Thanks for any info.

 

[ponytug]

FWIW, I think that the tool is called a spindle nut socket, and while it looks like a Tazewell special, you can buy them. The question being the relevant size...the one in Bob's photo looks like it is slightly over an inch.

Ebay:

All the best,

Peter

 

[bjustice]

Thanks, Peter. That may be a better solution--I checked out ebay.
Does anyone know the size of the nut on the trencher motor--or the motor model number--or where to buy the sprocket?

Bill