TD7G tracks eating angle cylinders

[Willie B]

My Dresser TD7G has chains maybe 1/2 worn. I presume the shoes were half worn out on a different tractor. They are 16", Dresser calls for 15".
Blade angle hydraulic cylinders are mounted in a very vulnerable place. Before buying it, I was concerned about minor damage, and the risk it might get worse. I initially addressed the notion of tightening the pivot where the blade push frame (C frame) pivots under the tractor. Wear there is minor, but I reasoned, every little bit helps. I did have minor damage where the keeper bolt head seats. I reasoned it was no big deal.

I then replaced all the wear guides, and shims that position the front idler.

Tracks ran 3/4" away from angle cylinders, but I reasoned they didn't touch, they'd be OK.
Early last winter, I lost a C frame pin. I believe the minor damage to the keeper hole was a bigger risk than I thought. This allowed the blade to swing right, ruining the blade angle cylinder on that side.

Replacing that cylinder proved a nightmare. I've run it some, Paint is wearing off the cylinders. I don't believe it is contact with tracks, I think debris caught in the tracks are doing it. Nonetheless, I don't want to go through this again.

I've considered cutting the shoes, or, I've found somebody who wants to buy my tracks, maybe i would buy new that would fit.

Any suggestions?

Willie

 

[mikebramel]

Put some wear bands on the outside of the cylinder

 

[Willie B]

I've seen this model tractor with standard tracks where someone had welded a piece of 3/4" x 2" a foot long to the side of the cylinder. I wouldn't do that, with my luck that'd deform the cylinder wall, and damage the internals.
I had considered some clamp on sleeve, but that takes up more of the space I can't spare. It makes it more likely it will hit.
Crossmembers could be lengthened, but the sprockets then would have to be spaced. Could sprockets be welded to? I have a lathe big enough to true up a spacer after welding.
Searching for a replacement cylinder, I've seen several of this model with damaged cylinders even among those with stock 15" shoes.

Willie

 

[John C.]

Any play in the C frame mount joints to the frame of the tractor allows the C frame to skew side ways anytime the blade is engaged in the dirt and the machine is steered to one side or the other. The usual failure though is that the lift cylinder boss moves to the inside and hits the radiator mount trunnions and can in fact tear them off the machine if the slop in the joints is bad enough. A half moon scrape on the nose of the tractor is the obvious sign that the C frame joints are sloppy and about to need an expensive repair. The problem got a lot worse when the H model tractors came out and there was an update that added a guide plate to each side of the tractor frame to help keep the C frame in line with the tractor and track frames.

If the damage to the C frame and angle cylinders is from the outside then the problem is likely from the track side of things. A worn out undercarriage would be the first thing to check. Are the idlers adjusted all the way out to the ends of the track frame? Are the idler bearings intact? Are the bolts from the hard bar to the track frame still in place and tight? Are the pins and bushings in the track chains worn out. Those are tight little machines and it doesn't take a lot for things to start rubbing on other parts of the machine.

When I get some time I'll see if I have some photos from some past inspections.

 

[Willie B]

Any play in the C frame mount joints to the frame of the tractor allows the C frame to skew side ways anytime the blade is engaged in the dirt and the machine is steered to one side or the other. The usual failure though is that the lift cylinder boss moves to the inside and hits the radiator mount trunnions and can in fact tear them off the machine if the slop in the joints is bad enough. A half moon scrape on the nose of the tractor is the obvious sign that the C frame joints are sloppy and about to need an expensive repair. The problem got a lot worse when the H model tractors came out and there was an update that added a guide plate to each side of the tractor frame to help keep the C frame in line with the tractor and track frames.

If the damage to the C frame and angle cylinders is from the outside then the problem is likely from the track side of things. A worn out undercarriage would be the first thing to check. Are the idlers adjusted all the way out to the ends of the track frame? Are the idler bearings intact? Are the bolts from the hard bar to the track frame still in place and tight? Are the pins and bushings in the track chains worn out. Those are tight little machines and it doesn't take a lot for things to start rubbing on other parts of the machine.

When I get some time I'll see if I have some photos from some past inspections.

Thank you.

I found slop in the slides that position the front idler, which I have corrected. The C frame has replaceable bushings that had been replaced recently before I bought it. There are four bores on the tractor frame that should not wear as the pin stays put in relation to them. They have minor wear. Pins are new. Line boring is very expensive, and would yield little change. The Expander System is priced to match the line boring approach. I would gain less than 1/4" with tightening these joints to zero slop.

Idler bearings are good.

Wear between idler at front, and track chains I haven't measured, and the shoes are 1" wider than factory spec. Perhaps cutting the shoes on the inside will cure the problem.

 

[John C.]

One photo shows the dead axle connection to the track frame. These can get very loose over time and cause problems. The second photo shows the wear plates installed on an H model tractor to prevent some of the damage you are describing.

 

[Willie B]

Dead axle seems tight. Front crossmember is good, and tight. Front idler is good, but I wondered if it had chains replaced without replacing idler, might there be space between the rib of front idler, and chain. Chains are neither new, or worn out. I'd estimate 50%. Shoes are too wide. I think I'll start with cutting down the shoes.

The pads attached to the track frame holding the C frame from wandering is a new idea I hadn't thought of.

Thank you for the advice.

 

[Iron@Dirt]

could your idlers and guides be sloppy?

 

[John C.]

Was also thinking that I've seen other makes of tractors with bent track frames. You might try running a straight edge or string line from the front to the back of the frame looking for a little bit of bend.

 

[Willie B]

The contact where it is a problem seems localized at top front of track where it flexes around the front idler. Two o clock, and 10 o clock. It is quite even on each side. I don't think there has been any actual track contact recently, since the C arm pin has been replaced. I believe recent contact is from sod, or debris the tracks carry with them.

Willie

 

[TimT]

could you weld a thin strap to the C frame where the track might contact the cylinder? Or no room?.. We had an old JD 40C that had such a loose inside blade that we welded a "guide" on it on both sides... just like the pics above but much smaller..it would still hit the pad edge on occasion but would just slide by on the guide instead of binding the track. Nothing on these old machines is ever perfect it seems. In particular if you relay use it. But what I LOVE about the old ones, they are pretty forgiving to makeshift repairs and a few broken or worn parts.... they still go for many hours. Plus no Laptop needed!!

 

[Willie B]

could you weld a thin strap to the C frame where the track might contact the cylinder? Or no room?.. We had an old JD 40C that had such a loose inside blade that we welded a "guide" on it on both sides... just like the pics above but much smaller..it would still hit the pad edge on occasion but would just slide by on the guide instead of binding the track. Nothing on these old machines is ever perfect it seems. In particular if you relay use it. But what I LOVE about the old ones, they are pretty forgiving to makeshift repairs and a few broken or worn parts.... they still go for many hours. Plus no Laptop needed!!

I have done so. I put 1/2" plates on the C frame, and on the vertical section where the lift cylinders connect. Unfortunately, it doesn't clear the cylinders when the blade is square across. Blade square, the cylinders are still the first to hit.

 

[pp13bnos]

Well, sounds like you might just have to trim the tracks down an inch or so.

 

[Willie B]

I have promised myself if I ever have daylight hours when the voices go quiet I'm going to cut them. I've miced the shoes, they are thinner on the outside. I'd prefer to cut the outside, and put them on the opposite side. I bought new track bolts, but the heads are too worn to rattle off with an impact socket. In the past I have MIGged the corners of the head, smashed an impact socket onto it, and impact wrenched them out.
Or, I could cut the heads off with torch. If I recall correctly, there isn't room to punch the track bolt through without its head.
The easiest way is to offer a BIG nut over the head, and weld it to the head. I've lost track of how many, but it's a lot of BIG nuts.
Tomorrow the voices just might be quiet a few hours. I'll try something.

Willie

 

[Willie B]

could you weld a thin strap to the C frame where the track might contact the cylinder? Or no room?.. We had an old JD 40C that had such a loose inside blade that we welded a "guide" on it on both sides... just like the pics above but much smaller..it would still hit the pad edge on occasion but would just slide by on the guide instead of binding the track. Nothing on these old machines is ever perfect it seems. In particular if you relay use it. But what I LOVE about the old ones, they are pretty forgiving to makeshift repairs and a few broken or worn parts.... they still go for many hours. Plus no Laptop needed!!

Don't slam computers too hard. If I didn't have a desktop I couldn't ask stupid questions here.

Willie

 

[Willie B]

I've spent the last hour trying to figure out what's wrong. The front idler stays where it belongs. Bearings are tight. My service manual gives specifications for several dimensions, but not the essentials. Track chains are SORFA. The ridge at the center of the front Idler is .900 narrower than the gap in the Sorfa chains. I'm wondering if I have a mismatch between chain, and front idler.

How much room should there be?

Willie

 

[TimT]

Don't slam computers too hard. If I didn't have a desktop I couldn't ask stupid questions here.

Willie

Your right Willie... For us old tractor guys the computer is awesome!! When you think about it, the knowledge available is way past incredible and they also make this hobby or business so much more fun to share our passion for machines...... Something to think about... Its a whole 'nother subject though...... I should have said "software"!!

 

[Willie B]

I've spent the last hour trying to figure out what's wrong. The front idler stays where it belongs. Bearings are tight. My service manual gives specifications for several dimensions, but not the essentials. Track chains are SORFA. The ridge at the center of the front Idler is .900 narrower than the gap in the Sorfa chains. I'm wondering if I have a mismatch between chain, and front idler.

How much room should there be?

Willie

Today I cut the track shoes by 3/4" inboard. It gives me a comfortable 1-1/2" clearance each side. I wonder if the track chain is also a mismatch. Is it possible that the throat in chain is too wide for my idlers? I'd bet the front idlers are original to the tractor.

 

[Bluox]

Today I cut the track shoes by 3/4" inboard. It gives me a comfortable 1-1/2" clearance each side. I wonder if the track chain is also a mismatch. Is it possible that the throat in chain is too wide for my idlers? I'd bet the front idlers are original to the tractor.

What pitch are your tracks?
Bob

 

[Willie B]

6.5" The standard track is listed in the manual as 15" Dresser also offered a 17" shoe with an extra 2" outboard.These shoes are on a Sorfa chain They are 16" wide, or were.