Lmackattack

Never ran tube tires.... I always ran what the mfg said was the max. unless it was a show truck, then I ran as low as 80 in the steer and 50 psi just for ride comfort to and from local shows...

Could also back the slacks all the way off so the shoes dont contact the drums

on older trucks it was possible. I think the problem with new trucks is the tractor protection valve??? If I recall you could hook air to the red hose. push the valve in and air could be put into the emergency tank to charge? With new trucks if its not the Tractor Protection Valve its the check valves thru the system that dont allow this. They obviously only let air flow one way. It shuts if air tries to flow back to the tank. Rob on the RS macks I put a air tool fitting on the wet tank. I can charge it with shop air if I want to move the truck without waiting for it to charge. a monkey wrench and a air tool fitting is all that is needed (besides the air!) Works great.

All I know is this same question seams to come up once every 3 weeks. A bad vibration can be so many things that many times its not just one problem... I had a bad U joint that took grease and did not leak out. Dident know untill I replaced it. then I had a bad drive tire. Belts were shot and was way out of balance. Worn cab rubbers may have magnified the issue so I replaced them at the same time..All examples shook the truck just the same. started at 35mph and went away around 50. if you stayed in the power it was less. worse when coasting... Its just one of those gremlins that you will have to chase.

2nd place that night search user "Lmackattack" on youtube for all the pulls we have made with this truck. 2010 pulls http://www.youtube.com/watch?v=zkyrSouBScg http://www.youtube.com/user/Lmackattack#p/u/10/Exyhst1zGLw 2009 pulls http://www.youtube.com/watch?v=8DHbjfdsZiM&NR=1 http://www.youtube.com/user/Lmackattack#p/a/u/0/zKvW12yLMWU

for those that like smoke. this was our first pull of the 2010 season... 2nd gear start..

IIRC my buzzer was under the dash near the steering colum. also had a low oil press switch hooked to the oil line near the LH panel that connector ran to a buzzer as well....

seams to be a common problem with macks of this era. Tires, driveshaft,U joint,Cab rubbers,Motormounts, shocks, springs are all possible things, Start with the easy stuff first.... Its never one issue. My truck had the same problem. it was bad shocks and tires

TRTXL1070 was the model number... It should be a OD transmission I checked and if its a .78OD that will give me about 77MPH at 2100 or 65mph at 1700. A little tall geared for a 285 but if I will have more low gears and a go home gear

yea I only drove the 100% air shift versions. drove one behind a 350 and one behind a 300. I like that you can drive it like a 5 speed. or split if you need. . with the 300 I would start in direct/1,2,3,4,5 then split to hi and go home in OD. I know the grind that you talk about. hard to get use to and know it hard not to..... Im thinking about bidding on it for my RS700L. off the top of your head...What top speed will I have with 4.17s? and LP24.5s. Im stuck at 62MPH/2100RPM right now. Speed limit in IL just went to 65MPH.

tires are unsprung weight. think of them like a basket ball. problem is we have 8 of them out back all bouncing. try this to see if it helps. First reduce the air press in all 8 down to about 20 psi then go bobtail around. if the bounce went away. it could be a tire balance issue. have them all ballanced. Most people dont balance drive tires but it can make a diffrence. I know it does on a car so it has to on a truck. other issue is that the springs really dont move much and they pivot at one point on the suspention. If you dont have shocks to help control tire bounce you will feel it. If the vibration is bad with a load on the truck it can be bad motor mounts, or drive train issues. I have even heard a bad power divider can cause bad vibrations ?

He is just pulling your chain, aka.... making a joke.

thanks for this info I may bid on this if the price is right... can you simply add a air shift for the aux box? and remove the stick? does it take the mack pto that runs off the lower counter shaft? also is this one of the only mack 2 stick transmissions that has the main stick on the out side?

thats what I was thinking... anything to look out for with the older model 12 speeds?

how do you shift the 2 stick 12 speed? Do you just use the main and split like the single stick 12? then use the aux for low and reverse?

saw a listing for a 12 speed , pics show it has 2 sticks and a air shift cover at the rear. all the 12 speeds I drove had a single stick with air splitter for Direct,Hi,Reverse on the stick and low low on the dash switch. ever seen this before

thanks for the link dan... the point was when he said "go left on Dundee Rd" I did not have to ask 3 times "WHAT WAY!" I dont talk on the phone when driving but do have a nextel..... beep,beep

Brad.. I spent all summer working on the RS cab. I painted the unseen interior parts with a rubber undercoat paint. then put dynamat throughout the whole cab. The cab floor I added dynamat, sound matt, and carpet on top of that. Under the removable floor I put a 2" foam,foil,insulation square. this square is used in gen boxes to keep the engine sounds inside. Fire wall has dynamat,soundmat, and removable Carpet sections that have insulation added. Rear wall has dynamat with 2" insulation between the interior rear wall and steel cab wall. I stuffed 5" of insulation in the cab corners. Roof was the hardest part as there is little room to stuff insulation. The under hood firewall will get some removable 1" foam. I can see it had this from the factory but was long gone before I bought the truck. I also will be adding 1" foam on the under sound of the hood and hood sides. I tested the hood foam and it made a huge diffrence when the hood was closed. Right now the biggest issue is the steering shaft hole in the fire wall and gear levers. those are the w 2 holes that let in the most sound. with the cab doors closed, windows up, engine fan off, its pretty quiet. If it was a newer electronic engine under the hood it would be just as quiet as a new pete or KW. I was on the phone with a friend and he did not know I was in a truck.... Trent

I must be lucky because most of the time at my Mack Dealer..... Northern Il Mack.... I can call and order R model parts and they likely will know the part number and can tell me if its in stock with out having to call me back.... Dan... what law just passed (dident pass) with the railroads?

thats great to hear. hope it keeps moving forward........ off topic ..Mack3P.... last year I recall you had to move if you wanted to keep the job? is that still an issue or are you secure for now?

when ever this happend I had a the air/water separater was clogged or the filter was old. Mine did this every 40 sec and after I replaced it (5 years ago) it acts normal. I really only notice it only kicking off after the gov kicks out.

RW they could have had ,285,300,315 HP 6 cyl macks as well as the line of V8 macks, off breed engines detroit, cat, and cummins I6 and V8-V12 models. Just about all transmissions offered mack and offbreed. common was mack 6cyl with mack transmissions but their were alot of offbreed drivetrain found in them due to the larger hoods.

thats is good news..

I have seen this on a few diffrent trucks. At work we have a 1996 IH that has a crossmember that was cut out with a torch so that the U joints dont rub... this was a factory fix!!!... Only thing I could think of besides replacing the crossmember is to add "stops" on the axel tube/frame so that it cant move that far up. some R models with camelbacks had these "stops". My RS700L has them

R models had some diffrent interior trim levels. in the late 60s-the 1972 years it was green steel and tan... pretty common and basic. With the intro of the R+3 cabs came more options but most common was the tan. Western R Macks I think had the most availible. I have seen Western R macks with Black,Gray,Brown,Red,Tan,and Blue. some of the interiors were very nice with embossed dogs in the seats and door panels. and diamond pleated cab walls. In the late 80s thru the 90s it was pretty plane again with charcoal being the most common. I dont know all the options but yes there was more than tan and gray