TC40A Tranny leak

[harwill]

I recently bought a 2004 TC40A with 225 hours in very good condition. Problem is, it has a fluid leak at the bottom of the hole plug directly beneath the PTO shaft. Tough to find because the fluid oozes into the Drawbar carrier and drips at another point. All told, it's losing about 2 oz/day this way. Anybody else seen this or got any ideas how to stop it? The plug looks like it could be driven out from the inside and replaced with a few hammer taps from the outside but I believe there is a bearing installed behind it. Any ideas? Thanks

[TedLaRue]

First a disclaimer: I don't own this machine and have never seen what you're describing.

But from your description, it sounds like a welch plug (a.k.a. freeze plug) sealing a hole bored to house or allow installation of a bearing. For other readers, a welch plug looks like a smaller version of a jar lid, but made of heavier metal and slightly oversized for the hole. It is driven into the hole with the cavity side out, and usually some sealant around the perimeter.

If your plug is a welch plug you should be able to remove and replace it from the outside. Try drilling a hole in it, doing your best to keep the "shavings" out of the hole. Be sure to stop drilling as soon as you're through the plug. Drive a sheet metal screw into the hole and use that to try to pry it out. Or try driving a punch close to one side to make the plug pivot in the hole.

If you have the means to accurately measure the inside diameter of the hole (ideally with calipers, but a good ruler might work), you should be able to buy a replacement plug from NAPA or other car parts place. Put some sealant on the perimeter of the plug and, using a socket from your ratchet/socket set which is close to the size of the plug, gently drive it into place with a hammer.

[harwill]

Thanks for the info. I talked to a NH shop manager and he was well aware of the problem. Seems somebody had a 'better idea' and 'rubberized' the sealing area of the welch plug. The one above the PTO shaft has already been replaced. There ought to be a NH recall campaign on that! A new plug sells for $18.25! Amazing! So I'm cleaning off the oil residue with brake cleaner and trying easy fix first, sealing from the outside. We'll see if that works. Chewing gum and bailing wire - keeps America running!

[jinman]

Thanks for the info. I talked to a NH shop manager and he was well aware of the problem. Seems somebody had a 'better idea' and 'rubberized' the sealing area of the welch plug. The one above the PTO shaft has already been replaced. There ought to be a NH recall campaign on that! A new plug sells for $18.25! Amazing! So I'm cleaning off the oil residue with brake cleaner and trying easy fix first, sealing from the outside. We'll see if that works. Chewing gum and bailing wire - keeps America running!

I am no expert on trying to make this kind of repair, but it just seems to me that if you don't do this job just right, you will end up with the same or a worse leak. How about finding a socket that will just fit up into the hole and tap it outwards to see if you can expand that metal and slow or stop the existing leak?

I've never seen sealant work on the outside of a leak. Even using high-tech sealant like they use on aircraft fuel tanks is always done from the inside.

Good luck with your repair. I hope you are successful. My luck is that I try and often end up making the situation worse.

[JC-jetro]

in line with what Jim said I would use a metal punch with flat bottom and a ball pin hammer. I then tap carefully the edge of the plug going around with the punch to hopefully expand and deform the lip of the plug against the hole. That may be enough to stop oil seepage. It is somewhat the same when the expand a fire tube inside of the boiler by using a tube expander as the pic suggests below.

[jinman]

in line with what Jim said I would use a metal punch with flat bottom and a ball pin hammer. I then tap carefully the edge of the plug going around with the punch to hopefully expand and deform the lip of the plug against the hole. That may be enough to stop oil seepage. It is somewhat the same when the expand a fire tube inside of the boiler by using a tube expander as the pic suggests below.

JC, I love it when somebody verifys that there really is something like what I pulled out of "thin air." A tube expander is exactly what I had in mind, but lacked the knowlege to know what it was called.

[JC-jetro]

JC, I love it when somebody verifys that there really is something like what I pulled out of "thin air." A tube expander is exactly what I had in mind, but lacked the knowlege to know what it was called.

Jim,

You always exhibit the traits of a " logical and common sense" and well rounded individual. I'm not surprised that you were on the right track . By the way the pic shows a fire tube boiler( fire in the tube and water around the tube). The tubes are long and cover the length of a boiler. Due to expansion of the tube at the higher rate than the boiler skin tubes are always expanded in the tube sheet and never welded. I had to replace a few tubes in one our facilities to squeeze few years more life out of an old boiler.

JC,

[harwill]

Thanks Jinman and JC. That was sure tantalizing to see the expander tool in the boiler pipe! Wish I had something like that that would work here. I'm trying to attach a picture (taken with the cell phone) of the problem that may explain things better. The plug has a raised center that protrudes outward. Darn it! The leaking area is at the bottom, beneath where I tried to seal it with the Gray gasket compound. Looked promising for about 24 hours then started oozing from the left end of the gray. If you look close you can see the trail running down from the left end of the gray stuff. Apparently, there's about 9 gallons of hyd. oil behind this plug. I was really hoping someone would say they knew of a NH campaign to fix the problem.

[BTI]

Is your drawbar mount bent? Or is it just the way the picture came out?
We had a Kubota a customer used to yank out trees.
He cracked the rearend housing on it.
You couldn't tell, it just looked like a leak until you scraped off all the paint.
If was actually sealing the leak to an extent.

I'd grab a manual and see how it comes apart.

BTI

[dynasim]

I am a bit suprised that it can't be relatively easily replaced. Is the collar shown supporting the PTO shaft, or is it just the sealing mechanism?

I will look at the shop manual tomorrow.

Chris

P.S. I would like at the drawing on the NH website. It is under transmission. I think that back device is just a seal.