ARRRRRRGH!!!!!!! Broke my tractor.... Engine Block went SNAP...

[KrisHansen]

One thing you might look into is a subframe mount for a backhoe. Those typically make a VERY strong connection between the rear axle and the loader mount. You'll lose some ground clearance, but you'll never again worry about breaking anything. And, if you eventually decided to get a backhoe, you could just pop it on. The big benefit is that the subframe is a reasonably simple bolt-on affair - you don't need to attempt to fabricate anything yourself. They're pretty reasonably priced, too - for my Bradco 611, I think the subframe mount for my TN70S came out to $500 or so, and that is a BIG subframe.

That's a great suggestion. I'll see if that's availible for my rig..

 

[shvl73]

One thing you might look into is a subframe mount for a backhoe. Those typically make a VERY strong connection between the rear axle and the loader mount. You'll lose some ground clearance, but you'll never again worry about breaking anything. And, if you eventually decided to get a backhoe, you could just pop it on. The big benefit is that the subframe is a reasonably simple bolt-on affair - you don't need to attempt to fabricate anything yourself. They're pretty reasonably priced, too - for my Bradco 611, I think the subframe mount for my TN70S came out to $500 or so, and that is a BIG subframe.

Other subframes may be as beefy but, he's right about the Bradco one. I have one and it appears to be 1" steel, and mine is most likely smaller than mahlers. I would think it can only help.

Re-thinking this and, looking at the location of the break, I'm not sure a backhoe subframe would help.

 

[dqdave1]

I would like to see your solution to the loader subframe. I have a 66" bucket on my TC29 and at times have lifted the weighted rear tires off the ground with weight in bucket. Relief valve didn't release so I figured I was ok. I do have the MMM brackets on mine if that means anything.

 

[KrisHansen]

I would like to see your solution to the loader subframe. I have a 66" bucket on my TC29 and at times have lifted the weighted rear tires off the ground with weight in bucket. Relief valve didn't release so I figured I was ok. I do have the MMM brackets on mine if that means anything.

I've got the 70" on mine, and I have loaded tires, with chains, and the blower hanging off the back. I would have thought it would have lifted the rear nonethe less, but I guess the engine is the weak link.. :/

 

[dogbreath108]

I don't want to distract from your main post, but on the discussion of the loader mount..

I took a few pics (I should have put more effort into it, sorry) of my 2120 with Alo loader. I know its a slightly larger tractor (its basically the TC 48-55) but it is still a compact and has basically the same type of block design, front axle mount and front axle. Just slightly larger.

What I am attempting to show is that it is solid welded steel, with bolts only on the rear axle mount, front axle support mount (which you can see), and the 4 bolts on the center housing (which you can't see). There is also a 1.25" solid steel rod with threaded bolted ends that connects each side under the tractor (it crosses just under the drive shaft). The design is solid and connects the front axle to the rear axle with out any bolted junctions in the middle. Most forces up down, side to side , twisting etc. are spread out along the entire tractor chassis. You could say (although it would not be entirely true) that the motor is just along for the ride...

I have two other much larger industrial machines, with very heavy loader backhoes from the factory. The same design holds true. Connecting front axle to rear axle with one solid or welded sections.

I am sure someone out there sells a loader for a approx. 30 hp tractor with this type of design. In my opinion, this is what folks should look for in a mount.
I think the 7308 is a good loader, and will give you good service life if you decide to replace your block. It does though take the other tractor components to there limit in design. A weak point here or there will eventually show (depending on hours of service). Also keep in mind that it is also not nearly as bad as a bunch of loaders out there maybe about 10 years ago that ONLY used a center mount on the center housing. These are completely junk and I feel completely sorry for anyone who didn't know and bought one. I can believe some of the major and minor mfg's at the time were going down this design road. In my opinion, it was completely unacceptable of them.

 

[KrisHansen]

I don't want to distract from your main post, but on the discussion of the loader mount..

I took a few pics (I should have put more effort into it, sorry) of my 2120 with Alo loader. I know its a slightly larger tractor (its basically the TC 48-55) but it is still a compact and has basically the same type of block design, front axle mount and front axle. Just slightly larger.

What I am attempting to show is that it is solid welded steel, with bolts only on the rear axle mount, front axle support mount (which you can see), and the 4 bolts on the center housing (which you can't see). There is also a 1.25" solid steel rod with threaded bolted ends that connects each side under the tractor (it crosses just under the drive shaft). The design is solid and connects the front axle to the rear axle with out any bolted junctions in the middle. Most forces up down, side to side , twisting etc. are spread out along the entire tractor chassis. You could say (although it would not be entirely true) that the motor is just along for the ride...

I have two other much larger industrial machines, with very heavy loader backhoes from the factory. The same design holds true. Connecting front axle to rear axle with one solid or welded sections.

I am sure someone out there sells a loader for a approx. 30 hp tractor with this type of design. In my opinion, this is what folks should look for in a mount.
I think the 7308 is a good loader, and will give you good service life if you decide to replace your block. It does though take the other tractor components to there limit in design. A weak point here or there will eventually show (depending on hours of service). Also keep in mind that it is also not nearly as bad as a bunch of loaders out there maybe about 10 years ago that ONLY used a center mount on the center housing. These are completely junk and I feel completely sorry for anyone who didn't know and bought one. I can believe some of the major and minor mfg's at the time were going down this design road. In my opinion, it was completely unacceptable of them.

Thanks, this is EXACTLY what I had in mind.. basically fabricating brackets to tie the engine to the center and then that to the rear... It'll take a lot of time, and some trial and error, but it will make for a much more robust overall package..

 

[Eagleview]

Good pics DB , its funny how one manufacturer sees the need for such a frame and others do not . Its either the cost of the frame that causes it to be emitted or the fact that the "engineers" with the CAD drawings on the screen don't have the "visualisation skills" to imput the correct data into the computer to come up with the appropriate design . When i look at a design like Kris's loader its obvious to me that its lacking a frame to distribute the load and common sense tells me the tiny thin wall clutch/transmission housing wont take the load , and even more so in extremely cold climates where hot engine meets cold cast housing . Maybe tractor makers should duct warm air from the radiator/exhaust past these components to help warm them .

 

[MikePA]

When i look at a design like Kris's loader its obvious to me that its lacking a frame to distribute the load and common sense tells me the tiny thin wall clutch/transmission housing wont take the load...

If this is true, why aren't there more failures? AFAIK, Kris' is the only reported failure like this on TBN and
there are other people on TBN with a 7308, weighted tires, heavy 3ph implements, snow blowers, etc.

 

[Robert_in_NY]

If this is true, why aren't there more failures? AFAIK, Kris' is the only reported failure like this on TBN and
there are other people on TBN with a 7308, weighted tires, heavy 3ph implements, snow blowers, etc.

I agree, I think Kris just had some bad luck in this deal. My 1920 has a 7308 loader also and I have abused it and have not had any problems and I have not heard of this on any other 7308 equiped tractor yet.

 

[dogbreath108]

I agree, he did have some bad luck. Poor block strength.

And there are more units out there with this problem. Of most every make. I also do think that the 7308 is a GOOD loader. I guess what you have to understand is that casting iron is not perfect. With bean counters running companys things are sometimes made to their engineered limit. Less iron less cost... There are many (if not most) machines out there with what you might call very slight casting flaws. Not necessarly cracks, but because of the rough surface a point where a crack could start. Depending on the thickness of the cast iron. When you increase the thickness you overcome this with less failures. The more you spread the forces out, the better off you are. It is what it is. Cast iron has very low tensile strength.

The mounting of the 7308 is called front loaded. Front loaded loaders put different forces on a tractor frame. Just like center loaded, full frame, partial frame etc. all put forces on different areas of the tractor. If I were to purchase new, I would look for a full sub frame even in a compact. Just to protect my investment... If the tractor had a lot of hours and had a front loaded loader or a partial frame I also would not hesitate to buy. But I would never buy a center mount unit. (you probably won't see a lot of these with high loader hours on them anyway).

If Kris were to have his block replaced (blueprinted using the old parts) I would not hesitate to buy and use with the current 7308 loader. I don't think that it is worth the time and effort in designing a better mount for this loader. It will also probably will be a bit more difficult that first thought. It was a front loaded design from the start and the tractor rates right up with others in its class. Although the block problem may not ever shown its ugly face without a loader on the tractor, or with a full frame mounted loader connected to the axles or whatever...

Front loaders are always hard on tractors, when you think of it, they should probably be mounted on the rear or the tractor. Larger axles, large rear and center flanges on the castings, no steering joints etc. But it would be a pain to drive looking backwards always to load. Then along came the pay loader

Joe