Lmackattack

here is our 285 powered sled puller. only thing done was the pump was turned up and puff disconnected. 40,000lbs and wheels spinning. 2nd direct. these motors can do some impressive stuff with just stock parts.... http://www.youtube.com/watch?v=ESgdON55V6E&feature=related http://www.youtube.com/watch?v=zKvW12yLMWU

I think that is the one that I recall. never worked on on that suspension but It looks as I remember it. I recall it did have a few issues but never knew much about it to research it. I drove 3 trucks with this style and always liked how smooth they were (for a spring ride)when empty. they also had 4 dampers(one at each corner) to help control the tandems... If I recall only the 2 or 3 upper springs made contact with the lower main springs when the truck was loaded. hard to explain but I think one spring was arched a little diffrent? correct me if im wrong? Trent

the taperleaf I think had 3 or 4 springs and had a nicer ride than camelback. however IMO they were not as strong and seamed to be used more in On road tractors. Camelback is pretty bullet proof and parts are cheep. both did good in the off road but camelback could take overloads alot better. Nothing wrong with either and if its not going to be used for work the taperleaf will put less abuse on you and the truck. just my .02

not sure. looking at it I would say it was a canadian built truck with the big OTR tanks and spread tandems on air ride... ??? there are a few pics of it over at ATHS. I passed this truck on I80 about a week ago and then It showed up at the National ATHS show in CA over the weekend

bump the injection pump settings up 15-20% install a front mount if you have the room. if no room tweak the tip turbine boost inlet valve a little to allow more boosted air flow into the turbine. make sure the puff limiter is working correctly or disable it..you should feel a increase with this advice. Trent

chop cut and weld on to the current frame. I will put some inner frame rail channels across the welds and bolt them in between cross members on both sides of the weld. Im thinking I will stretch it to about 200" WB and this way if I want to add a sleeper down the road I will have some frame rail to do so.

have fun with that Larry. Think Ill let you test the waters with a old newway set up going under a B model. I have a neway tandem cut off that Im getting from a friend. As soon as he has time to cut it out of a junked tractor I will freshen it up and install it. For now I will just watch you and avoid any of your mistakes LOL!!!!! thanks trent

well got the driver side out tonight. came out easy as there was some rust in there with it. looked to be original glass as I saw a date safty stamp of what looked like 1977...LOL. it came out easy and a new rubber went in nice and snug. While I was in there I installed some Dynamat to help sound dead the truck. This weekend I plan to install dynamat in the other door,floor, rear cab wall and fire wall, Hopefull it will help quiet this truck down as its pretty noisy! im adding a 1/2 thick pad on the floor and fire wall so we will see if that helps Trent

I have never tried to remove the door glass from the channel that it rests in. how hard is it to get it dislodged from the rubber that holds it in?..fyi...im not talking about removing the DOOR panel.. thats the easy part!

Brad....your dads looks just as good. just not as much bling as this OTR truck has.

real clean R model that Art387 took from the road. also a few of a KW and FL all heading west on I80 last week.

good info guys, thanks....when I got the truck the roof had a few rust spots and I did some local repairs, now some more have showed up and I know its going to be a little ugly behind it. the only other places the truck has some issues is around the rear window, door bottoms and a few small spots behind the lower door molding. I would like to save the cab now and not have to replace it 10 years down the road... what do you figure a body shop would charge to do the roof work? this is if I had the cab gutted and ready to work on?

I have not seen a E9 in a RS700 yet but they did put V12 detroits in them (factory build) plenty of room to fit a E9. If they already put a front mount intercooler in front of the radiator for the 300... 1/4 your battel is done. alot of the RS models had the front engine mount tied in with the rad mount (all in one casting) leaving no room for a front mount intercooler between the rad and hood....hopefully they made room for one? Engine mounts may need to be changed/relocated back and a new hole may bee needed in the cab floor for the stick shift lever. If the truck has power steering it may need some provision to get the steering linkage to work? if its still set up for the older V8 you should be fine. would love to see some pics of the project!

My RS had a roof mounted AC unit. When I bought it it had a plate bolted to the roof in its place. I half assed patched that but now under the rain rails its starting to rust/bubble where the roof meets the cab sides. Is it better to replace the whole roof or can I just make a repair under the rain rail? If I make repairs I dont know if the rust will continue to spread? If I remove/replace the whole roof and let some por15 get down in the insides it may slow any rust issues down the sheet metal.. never done this before. Trent

if the truck has Power steering you will need to remove the pump as well. just 4 bolts if I recall and it slides back. you should not have to remove the return and feed lines to it. not a bad job about 1 hr to remove all the stuff and a little longer to get back on. thats if you have the room to access all the stuff.. Trent

I should mention this is kinda common with other makes as well.. we have had 2 3406E cats at work louse the seal in the cups and eat the injectors.

that is good news. What erks me is that I always hear people say the best truck for garbage hauling is Mack as they are built like Garbage. while I disagree I Kinda feeds fuel to that fire. The Mack Name needs help. Its lost out on the highways and lousing ground in the fields. Heck I cant find any flashy parts for a CH ,vision etc...mack at a chrome shop that are specific to mack. I just wish they would have promoted the name more rather than cutting it up with a big CAT

No. He mentioned mack one or two times and it was about the mack engines exhaust system. Again a little back lash to the mack name "look how dirty this engines exhaust and soot is.... but that ok this filter here fixes that before it leaves the tail pipe, thats why you dont see the truck belching smoke" Job well done Mack......

yep another bad idea for emission engines. lets put the injectors in a jacket that has water and if the injector cups or orings fail you will mix water and diesel... not to mention 1 electronic injector will cost the same as 6 mechanical injectors do.

saw the show and if you ask me what I thought of it....It gave off the impression that they took a cheepo truck and cut it apart knowing it was cheep junk in the first place. look it can lift 8000lbs but not 10,000lbs.... lets see what this POS is made of now as we cut it apart. We all have seen Monster garage and myth busters, they dont bring in a 2010 new cadillac and cut it up, that would cost to much. besides why would cadillac want their new pride and joy shown in a distructive matter? Instead they get a junk car and turn it into something "cool". With all the shows on TV its sad that a volvo/Mack rep thinks that takeing a new garbage truck and cutting it up making it look like shit will bring in more sales. This is beyond me? Is it not better to show that their new truck / engine will beat a cat powered pete out of muddy dump site or up a steep hill in the off road? show that the truck can be dressed up with some chrome? I think that this show gave more of a discrace to the Mack name than "wow this truck is something to talk about". just my .02

If I can add to this. R700s could sit as tall as a standard 600 or they could be slightly higher with the use of diffrent mounts to get the cab higher off the frame. Most of the 700s I see sit at the same hight of a 600. The mid-late 70s RS/RL have diffrent hoods so dont look at them for measurements.Consider if you want an air to air intercooler in front of the radiator. you will need about 3" to fit the intercooler so plan on moving the rad back a little. you will need to bend the gear levers to fit in the cab and the cab floor will need the holes for the sticks under the dash closer to the fire wall. If you want air cab suspension. secure the radiator to the frame with steel rods to hold it steady. dont use the old style "x" brace. sounds like you have your hands full!!! Trent

the standard R models had the exhaust run from the turbo down below the frame rail, along the bottom of the rail, exiting and bending upwards behind the RH fuel tank. If the RH fuel tank was large and did not permit the exhaust to route up behind it, you can have it come up between the frame rails. If you ever watch Mad Max the road warrior you will see a good example of how you can get twin stacks to work on a R model with big fuel tanks. hope this helps.

Macks of that era likely had a automatic power divider. the dash switch operated was a option as well. the auto power divider has its good and bad. the good is if its not worn out it kicks in automaticly before you know you need it. the bad is if you do get stuck you wont know for sure if its giveing you the power transfer you need. the old trick if you got stuck in slick mud or snow with the auto PD...was to lightly tap the brake pedal as you were spinning the wheels. ( dont stand on the pedal!) this may help the power to transfer from the spinning wheel to a stopped wheel and help you get out.all your doing is resisting the free wheels from spinning in hopes the stopped ones grab and get you out. Remember most trucks have open diffs so in reality we only have one wheel drive. All the power divider does is sends power to both axels giving you 2 wheel drive when more traction is needed. all depending on the weight thats over an axel and how slick the ground is will depend if you can spin 1-2-3-or all 4 wheels at the same time. hard to explain without showing someone in person with parts in hand. Regardless you can buy an air operated PD and install it. should be easy to find parts.

they did make great ready mix trucks. I think many speced them with the 6 speed with the ultra low low gear. you could start a fully loaded truck without the clutch. LOL just grab the shifter and find low low. all the slop in the gear box would not even bang a gear LOL!!! thinking out loud here. a 285 in a u model will have a few tight spots in the engine bay with that short hood. but liek Bullhusk said. they run for ever and need little attention. I have a 285 in my 1977 RS700L and its numbers matching. turn key truck. I can out pull a 427mack up to the top of 4th gear or about 45-50 MPH. When Empty It looks like they fell asleep at the light. It cant compete with the new cats or cummins but hell the new motors have 2x the hp/tq. if it can hang with it a little its doing pretty good. Dont forget its a 30 year old outdated diesel!!!! oh and the EPA wont like the black clouds like we do!!!!!!!!

in their day they were pretty good when compaired to engines of the same era. many said that a good running 300 mack would hang with a 350 cummins or cat. I think one of the down sides to the maxidynes was that they liked the low RPS better than the upper RPM. this means the engine pulls harder the lower the revs are.good for off road but not the best for a hill. You will have to use 3rd on most hills pulling at 1400RPM thats about 30MPH or so. also with the gearing of a 5 speed you dont have that choice to spit a gear to get a little more MPH. if you can get over the slow hill climb issue you will find that the maxidyne will pull good in the first 4 gears and once you hit 5th your good untill a stop light or hill. Here In IL the 285 / 6 speed is a nice simple and reliable set up. if your in CA or in the hills alot you may not like it so much?