Alabamaslammer

[alabamaslammer]

Hey guys. I had some rust jacking in between inner and outer frame rails. I've removed most all of it with a sledge. Now trying to figure out how to get the frame back together - there is an inch gap at it's worst where outer frame rail separated from inner on the top of frame.. Tried map gas and sledge hammering a piece of wood and it had no effect. The c clamps with impact wrench adapter end cost 400 bucks and those for 10 inch.. I need bigger and would need a few.. Does anyone have experience doing this? Was thinking maybe acetylene torch and a loader pressing/hammering a long piece of iron laying across top of the frame rail where it is bowed up. Or a big hydraulic press and big piece of iron to make sure it lays back flat. Don't have any of those things. 

[mechohaulic]

any info on this unit:: dump truck/ tractor: daily runner ? separation over rears ; between rears /cab?  only reason for asking is for figuring proper repair. I wouldn't go toooo much with the heat ,wrong area of frame could possibly lead to cracking after. that far a separation on a daily runner may lean toward frame rail replace . depends on your access to tools .

[alabamaslammer]

It was a dump truck. Will put dump bed on it or 5th wheel. All the separation is in the rear. Thought about replacing outer frame rail sections from cab back but looked better than expected after removing rust and guessing there is a way to correct gap. Here's a few photos 

[mrsmackpaul]

From what I know and everyone knows thats two tenths of SFA the rails need to be fully seperated to clean the rust out fully to allow them to close up

Apparently they allmost always spring back into shape when this is done

So sadly I think you need to go all the way to get the result your chasing

I have never done this and am only passing on what else I have seen or been told

Get your self a 3/4 cordless rattle gun and get into it I guess

 

Paul

[MACKS]

As for the outer rail I would heat it and whack it with a big sledge,if u don’t use heat your gonna crack it..

[mechohaulic]

pictures sure help in proper suggestions. that far back ;; i go with MACKS  recommendations.  between cab and rears is a little different .  don't think it's that bad to use a loader down pressure. challenge is when that much hammering is done , you don't know how much is on the sides between two rails that will flake and stay.

[JoeH]

You gotta pull the rails.  One side at a time. One side stays on to hold alignment of everything while you crib up everything on the other side. Axles, transmission, engine, cab.... Hood comes off, fuel tank off, battery boxes rest on the floor...  Detach everything from the rail. When you're ready to pull the rails, look it over again, because you forgot something.  Ground wires, some dumb wire clamp, etc.

Once rail is off you start at the back and drive various implements in to pry the rails apart, being careful not to kink the rails. Once it's apart the rails spring right back where they should be, they're basically spring steel.  No press needed.  Sandblast, prime & paint, (single stage automotive is best IMO. We tried "Chassis Saver" on one of our trucks but that stuff the gloss fades pretty quick to a flat black.)

[JoeH]

The truck in these photos is an mr688s that we did all the above and more to last January.  Second truck we have done this to.  It's a lot of work, but if you have a month and a helper and the know how, the end result is a truck with a second life on the frame.  Our business is seasonal so we had the downtime, and we needed to get this truck ready for a brand new volumetric concrete mixer by February.

[JoeH]

Your frame hasn't sprung back closed because you haven't gotten all the rust out yet.  I do know one shop that left the frame in the truck, and separated the rails from back to cab, sandblasted and painted what they had open, then bolted it back together. End result was good, but I'd worry about kinking the rails if leaving the cab forward bolted together.

[JoeH]

On 11/20/2022 at 8:35 PM, alabamaslammer said:

Hey guys. I had some rust jacking in between inner and outer frame rails. I've removed most all of it with a sledge. Now trying to figure out how to get the frame back together - there is an inch gap at it's worst where outer frame rail separated from inner on the top of frame.. Tried map gas and sledge hammering a piece of wood and it had no effect. The c clamps with impact wrench adapter end cost 400 bucks and those for 10 inch.. I need bigger and would need a few.. Does anyone have experience doing this? Was thinking maybe acetylene torch and a loader pressing/hammering a long piece of iron laying across top of the frame rail where it is bowed up. Or a big hydraulic press and big piece of iron to make sure it lays back flat. Don't have any of those things. 

DO NOT APPLY HEAT TO THE RAIL! They're heat treated.  There's special processes to follow when heat is involved with rails.  Every manufacturer has their own guidelines for weld repairs to frames to keep heat stresses from occuring. I have to reiterate that your rails haven't sprung closed yet because there's still rust in there. splitting the rails is the only way to get it out.

[mechohaulic]

the proper way is always better providing a person has the correct equipment to do the job. i mentioned in earlier post the possibility of the rust/scale in between the rails after excessive hammering.  assisted in a rail replacement number of yrs ago. as stated , it's a major job requiring safety as #1 priority.  too many heavy items hanging .  nice job Joe

[mechohaulic]

Joe ;; is the cab supported by the over head crane. i would think a COE would twist the rails when raised  as in photos. real nice job.

[JoeH]

8 hours ago, mechohaulic said:

Joe ;; is the cab supported by the over head crane. i would think a COE would twist the rails when raised  as in photos. real nice job

Cab is suspended from timbers spanning across top of A frame to our pallet shelving.

[mechohaulic]

thanks for pictures. darn nice set up for such a major /challenging project. a C O E might seem easier having front half access, but a lot more things can go wrong doing it improper. 

[JoeH]

Easiest truck we have ever worked on. Flip the cab forward and you have full access to every side of the engine. Transmission too.