Broken Frame on R686ST

[LoggerGary]

I have a 80 model R686ST. The frame is broken on both sides in front of the tandems. The previous owner was pulling dump trailers with it. I used it to spot log and chip trailers on a logging site. The other issue we had it was geared to high for our application. Really would like to fix frame.

 

[Mark T]

Lots of work to address both those issues.  Maybe a bigger tractor that needs an engine like in your truck ??? 

[70mackMB]

Gary, Welcome to BMT!  What was the angle iron, bolted thru the top flange, used for? Was it meant to be a temporary repair or for something else?    .....Hippy 

[Joey Mack]

since its a site truck, can you get 2 peices of inner frame from double frame truck, and overlap the cracks?  then weld the crack shut after the overlay is in?  A full frame replacement is a lot of work, even on a short truck like yours..  I know JoeH can atest to that...  

[tjc transport]

proper way would be to strip that section of frame, v notch both sides of the crack, then weld it on both sides. 

once welded find an inner frame section to bolt over the weld with plenty of extra on each side of the weld. then fish plate the outer side of the frame. 

[Mark T]

For what he's talking about, he'd be better off splice'n a bigger lower geared cut off to it (like out of a CL) . Some of those Rs  (like that one) had tiny frames and some don't even have a shim between the crossmembers. I've done repairs on those and had a local guy bend some flat plate like a liner for the frame. Crossmembers had to be shortened. Lots of work. He's not content with the axle either , aside from the broken frame. 

[Mark T]

1 hour ago, 70mackMB said:

Gary, Welcome to BMT!  What was the angle iron, bolted thru the top flange, used for? Was it meant to be a temporary repair or for something else?    .....Hippy 

😂 that bolt through the top flange is exactly what it needed

[Joey Mack]

good point about the gearing.  

[Joseph Cummings]

Are you going to ever use it on the highway? Here in the anthracite region if it wasn't going to see the road it would just get welded up and even the fishplates welded on 😄. Burn it in with 6011, and cap it with some 7018 passes.

I'm guessing you have 3.87 ratios. What do you expect to do with this truck. How fast does it have to run. you can find some really low ratios out of something with an overdrive trans, and end up with a truck that tops out at like 35mph but will pull anything