JoeH

1995 RD688S won't switch from cab heat to defrost. What should I look for?

Probably, with the right flywheel housing.

Great read! Thanks for taking the time to post it!

9 hours ago, Butchee said:

Hi Gents I have a 1989 RD688 and want a cab. I have some good doors. Would anyone know what cabs will interchange and what years ?  ?  It looks like the rd690's cabs  are the same and most all the RD years look the same..to me .  Thanks 

The R cab is primarily unchanged, with the exception of adding 3 inches to the back side of the cab in the early 70s. Might be minor roofline changes, but that should be about it.

Triaxles tend to have a good amount of twist/flex to them going down the road, simply because of how long they are.

Looks like the weeds are going to be prohibiting that trucks freedom soon...

On 10/11/2019 at 5:40 AM, Roscoetaggart said:

hi guys

 

In the process of restoring my r model currently, I am after two alloy round fuel tanks and have found two that are off an early ch in good condition, will these tanks fit my r model? 

Cheers

What size are you looking for (gallon capacity) and are you opposed to buying new? My '95 has aluminum tanks, if you use my vin at the dealer it should get you a set of ~50 gallon tanks....

Your local Mack dealer. A good parts guy should have no problem looking up the book for your motor.

On 3/9/2018 at 8:46 PM, suejoe6174 said:

nice set of b model fenders and inserts  500.00  

Bump

The last 6 digits is all they need. If it doesn't work they're dysfunctional. And the last 6 are numbers.

Here's a 3 knob setup.

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.

15 hours ago, other dog said:

I love this stuff, true examples-

The late Gene Dixon, owner of Kyanite Mining Corporation,  once tried to check in to a fancy motel in the Norfolk/ Va. Beach. They refused him a room because he looked liked regular folks, and he had been drinking, as the story goes. He bought the motel and fired everybody. 

Johnny was in the Southern Belle Truckstop in Berkeley Springs one night, got to talking with a couple of other drivers in there. When they left and went outside, one of the others said "what are you driving?" He pointed to an F model with a load of green lumber and said "that Mack". They said "would you mind if we pulled out first, so you won't hold us up- we've  gotta go!" "No problem, go right ahead".  They were both driving "large cars".  He pulled out behind them, and then he proceeded to blow their doors off going up Town Hill Mountain with that V12 F model.

Wayne stopped by the IH dealer in Greensboro, N.C. one time. He wanted to buy a new truck, but he was in his work clothes too. The salesman wouldn't give him the time of day, not realizing that Wayne could build a truck out of parts in his junk drawer. He bought a new truck, paid cash for 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.

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.