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.

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.

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.

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.

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.)

Curious minds want to know what you might do with the em7. Those curious minds might be interested in it...

50 minutes ago, 70mackMB said:

I check this thread almost daily for these pictures.  Always good for a laugh. 

K, I don't check the forum very often, usually once a week or so. Send me a PM if you are interested in the motor. I'll see the notification.

I've got a 237 with a 5 speed mack trans bolted to it. Engine smokes a bit, doesn't like to start in the cold. Most everything else on the truck is gone, and we haven't had it running in a few years.  Was a U675T, I think 1974 or 1976. If your engine is no good then send me a PM, I can check with my dad to see if we want to sell it. 

Zip code 18914.

The frames are virtually unchanged over the years. You should have no problems finding donor parts from a wide range of years that should work with whatever spec your truck is. Mack did a good job reusing cast frame and suspension components for decades.

Looks like it bolts right to the front of the block/timing cover. I didn't look real close.  1995 RD688S, e7-350, mechanical.

Got you some pictures this morning.

And truckers wonder why cops do DOT stops...

I think they need more duct tape.

TJC is probably right.

Rockers look like those on an Iranian Mack that Vlad explained about a few years back. Would seen strange to import a Mack from Iran to the States.

The old 2 stick Mack transmissions are usually around 1,500 lbs I think

I've pulled rails out of a few trucks over the years. Are you talking Rust Jacking horizontal cracks along the flanges or are you talking a vertical crack? Or a stress crack from how the dump body rests on the frame just behind the cab?

To remove rail, you have to remove truck body, then block and support everything along the side you're removing. Axles, transmission, front engine crossmember, radiator, can, etc. Fuel tank comes off, battery boxes come off, lift axle comes off, hood comes off, tires off, etc. Unbolt everything. Slide an A-Frame or crane boom over the truck, hook the rail, and expect there to still be something attached.  Ensure it's entirely free and slide it out the back.  

Double Rail can be separated with time and patience by driving a 2x4 in from the rear end of the frame. But sounds like you're into rail replacement depending on how bad the cracks are. Mack Frame Repair Manuals outline how weld and repair rails.

If it's Rust Jacking then you're supposed to do this repair before it gets that bad.  You get a rail out, separate, sandblast/paint, slap it back in and the do the other side. One side holds alignment while you do the other side.

Our most recent project involved all of the above and then some to prep it for a brand new CemenTech concrete mixer.

They can charge you more if they spend more.

You guys missed one point on insurance since Obamacare.  There's an 80/20 law on insurance companies margins.  They have to spend at least 80% of what they collect in premiums on healthcare.  Sounds nice, curtails how much they can charge, right? Wrong. It's a racket.  They just let the hospitals charge more because if the 80% dollar value is higher, then their 20% margin they get to keep can be a higher dollar value too.  

Check the oil level before you drain it, if it was running on oil then the level would likely be low?

I'm guessing lines hooked up wrong because they had the trans out for the clutch.  But my 8ll had a cracked combination cylinder piston.  It's a disc that slides the hi lo shifter fork back and forth.  

The pump is live, always on.  On trash trucks, the pump has a protection circuit.  If the hydraulic system loses oil, a butterfly valve closes and oil is circulated through a metal pipe from the pressure side of the pump to the suction side.  This way you can limp the truck along without destroying a $3,000 (guessing) pump.

I have a 2003 MR688S also that had a pump on the front.  It has the tall radiator like you mentioned with a hole through the middle. let me know if you want pictures, but it is a different model altogether.