JoeH

Australians really know how to doll up a superliner right!

I believe on the Eisenhower interstate system, the roads are designed to federal weight limits unless the state had even heavier weight limits, i.e. in Mass with the 77k permits. In such a situation the federal highway system is built to state standards. In PA a triaxle is good for 73,280, and a standard tractor trailer 80k. On bridge laws in PA a short tractor trailer with 5 total axles cannot gross as much as a triaxle can, which is irrational because you're longer than the triaxle and you have an extra axle. That 98k DM686 is safe so long as you have the heavier brakes and you maintain the truck in good working order. I have a retired dm686sx with 58k rears and 20k front, had a lift axle. It was always able to stop faster than our other triaxle with 44k rears, with a load on, even with the lift axle up. Bigger circumference on the brake drums means more surface area and better mechanical advantage to slow down. If your lift axle has the bigger brakes as well as the drive axles then you should have no problems stopping 98k. Getting it moving with an endt676 on the other hand is another matter. It'd go but not in a hurry!

With engine off, key on you need to hold the set/decel button til the lightning bolt starts doing stuff. Count the flashes, it'll be a 2 digit code. When that code is done spitting out, hit set/decel again to draw another code. Each code request gives you one code. This method will only pull "active" (current) faults. You need a computer to pull stored, inactive faults. Post the list of codes you pull here, and some of us have the book and can tell you what the codes mean! And start by replacing the fuel regulator as well! And next time don't leave out pertinent information!

Any codes? Is your engine malfunction light in working order? That'd be the lightning bolt on the dash.

Define your "hard starting". If it has to crank for 5 seconds or so before firing off then your camshaft position sensor could be failing or has enough buildup to screw up the reading. It's on the front of the timing cover, in front of the camshaft!

Apart from the rails everything else just looks like standard surface rust. Macks was thinking it had what we call an Eagle at the trunnion. It's basically a 3rd rail that goes inside the frame at the trunnion, and acts like a gusset to keep everything square. My DM686SX has it, because it has the 55k springs. But yours is an S, with the 44k cameback, which doesn't need the Eagle. (Called an Eagle because of the taper) you can see the rear of the eagle on my DM in this picture. As well as what's going to happen to your frame any day now from the rust. Only reason yours is not cracked yet is there's no stress on it from weight sitting on it.

Hard to decide which story I like most. Maybe Gene Dixon's?

Likely both; I have a 95 rd688s mechanical, but v-mac I was available I expect.

Classy.

9 days left on it, it'll go up.

Could you imagine trying to teach a jury the mechanics of a fuel injection so they can deliberate? Let alone an injection that allows the fuel to flow backwards into the injector? I suppose pulling your own fingernails out might be an easier task!

Link to the post? Was there a solution in that post?

You're on the right path, just make sure you put blocks between the frame and body before you go under there.

It would pressurize both sides and the fork would freely slide back and forth, destroying the gears? The air moves it and holds it too I expect.

How hard is a good flatback u cab to find? We have a 1976 u685T dump we might put back on the road but the cab is crusty! Dad plowed and salted with it for a while.

Does the cab tilt forward on an MR? I guess the trans is under the trash body? I'd hate to say you need to pull the trans, but you'll need more than 8 inches of head room. May have to lift the body off or drop the trans. 12 inches you might be able to get away with it if you're skinny...

Its bad, but like ws721 said if it's a good truck and you like it it's probably cheaper to fix than to replace. Question is whether or not fixing it is worth it to you. Some people dig out the rust by beating on the rails and vibrating them to shake the rust out, but that doesn't get the rust out at the bend in the flange. If you take it apart you may find holes in one rail or the other, or paper thin rails. All that rust came from your rails, so they're thinner than they were when they left the factory. Thinner & weaker.

Cutting and splicing PG Adams rails is not a bad idea, but it will also require separating the rails to get your welds right.

My 1980 DM686SX has two 3/8th inch rails. Rust jacking is a awful. Last 8 feet of the top rail: outer rail is cracked along the transition from sidewall to flange; inner rail top flange is just rust cancer. Nothing substantial left. And our trucks don't go out much in winter. If yours hasn't cracked yet you might be able to save it. Pull one side of the frame out at a time, separate the rails clean and paint, then reinstall and then do the other side. It's a chore but the trucks not going anywhere anyways. Cost is roughly $1,000 in new bolts, plus one or two possibly cracked crossmembers, plus sandblasting and paint + your time.

Hahaha

Sounds like you need to install a left turn signal on the truck! Kinda silly having a truck with no left turn signal!

Not sure what access is on your t2060, the 8ll is easy to fix from the rear of the trans. We have 1988 RD690S with a t2070? that we had to take the range selector out the top because we had to take off the rear mounted PTO for repairs and a countershaft dropped. Had to jack the back of the cab up as far as we could plus we conveniently had a hole in the floor between the seats. Was doable, but it needed 2 or 3 sets of hands at times. Not sure how your access will be.

+1 on possibly a vent line. Could have a leak in the range selector cylinder. What happens is one side is hi other side is low. If the oring between the two fails the air will bypass from selected range to vented range. Thus, your "leaking" vent line, because the unused side is switched to the vent. I have an 8ll that did this, but the orings were fine, but the disc that is the "combination cylinder" was cracked in 3? places.

What year truck and engine are you working on?

I don't get the Jan Brett reference. This is where I heard honey Badgers from: