Lmackattack

it can be from a bunch of things. This seams its a common complaint on old r models mine does the same thing....sometimes? bad U joint bad center support bearing bad tires bent rim flat spoted tires. even heard a bad power divider cound send a vibration unbalanced drive shaft. badly worn torque arm bushings

thanks for that info David.. when did they start using plastic timing gears!!!!!! so far oil is clean and never had to replace anything besides tires....

The american auto makers inthe 90s, weather hands tied behind their backs or not, could not compete with imports of the same day. I do think that has changed in the last 6-8 years as American cars have come around and basicly cought up in most aeras. I had a 91 toyota that out lasted 2 GMs. I now have a 97 riviera 120,000 miles and love it. not as nice inside as a lexus but it is very smooth powerfull and trouble free. USA made and proud to own it. Vovlo Cars were owned by for for a while now. Volvo Trucks (last I checked)and constrcution is still owned by the powers in..... Sweden?

A little off topic but want to put the word out that I have some HO scale Macks that im selling on ebay this week. I Have some old B and R models for sale and a Freightshaker. I will have some R doubles and R mixers up for sale next week. If you know anyone with an Ho scale layout give them the heads up. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280452474272&ssPageName=STRK:MESELX:IT http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280452522691&ssPageName=STRK:MESELX:IT http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280451175720&ssPageName=STRK:MESOX:IT Trent

Mike I dont know that mack has the bank roll in this poor econmic times to consider such a thing. look how slow the Titan sales are and thats the newest line up introduced in the last few years....I still think the Titan should have been introduced as a super liner but what do I know????

welcome to the site. Always good to have the ears of the guys building and testing the trucks around us. We have alot of Die hard mack owners here and its good to see that you are one of us. Im not speaking for all but just to get it on the table most of us dont like the "V word" and now that its in charge of mack many fear what direction they steer us in. Alot of us here have old macks that seam to just keep on going and its sad for us to see new macks with less of the proven mack drivetrain parts . It seams the offbreed stuff is getting forced on new owners?. I cant comment on alot of the newer stuff as my newest mack was built in 77'. From what I hear its become apperent that Mack is having some trouble trying to compete with the old R models when (V word) is putting more plastic and offbreed parts on them. EPA has not helped us and some QC issues have come up over they years as well that forced mack owners to look at paccar. We all want to see Mack improve and we will strongly voice our opinions on what works and what does not. If you got stories of what you found is working out on the testing grounds,Im sure we can share what it does in the real world. Welcome to the club. Trent

fill the rear box and wait 10min and check it again. the cold weather will realy slow down oil flow to the other boxes.. All the boxes pass oil to each other via "splash lubracation" Check the magnet plugs and your good to go. Thats a great trans, keep it healthy!

cant really tell by looking at it what condition it is in. If it has lots of oil leaking it may need seals. Check the mounts as sometimes I have seen the bolts round out in the alum case. The twin stick will need a 2nd hole in the floor but its easy to make as its directly next to the other stick. Many people will remove the seats and floor boards to get better access to the top of the trans. Drive shaft lenght may need to be adjusted..I cant recall how much longer the 6 speed is? I have seen those old 6 Speed boxes sell as low as $250!The avg I see is between $500-$1000. the 12 speeds sell for alot more. the 6 speed box is pretty simple and can be rebuilt fairly cheep. those gears are stronger than superman and rarely need to be replaced. The Forks and shift rails wear or get damaged faster. If your looking to do a cheep repair I suggest you rebuild the shift cover as that will tighten up the feel of the box. Also do the rear main and Shaft seals while its out. Its one of those jobs that you have to ask yourself.."When the trans is out what els should I replace?" Trent

My 6 speed has the mack PTO, it mounts to the lower countershaft and has a long spline shaft that is powered from the front box. as long as the aux is in gear it will pump.

Yep. the 6 speed will give you one lower forward gear and 5 reverse gears. top end stays the same as your 5 speed. the 6 speed comes in 2 stick or air shift. There are a few versions of 6 speeds,you will need the one HK just mentioned. If you want to increase road speed you will have to look for transmissions that work well with the Maxidynes, A 12 speed is a option but they are getting hard to find.

and he was going nice and steady like a good drive would. no throttle revs? must have been a weak joint? front end was looking a little light. Glad his brakes held!!!!!!!

Nice find!! Hope you gave it a good home?

My B model with a Quad and 5.73 is geared for 62MPH. I think thats at 2100RPM. I could likely get 65MPH @2300 but its never left the yard! LOL Trent

its got to be a mack triple countershaft........Mack 12 speeds would seam right to do the job??

Gambi..If you have a matched set your fine. The diffrence is that when the tires are of diffrent sizes the Diff spider gears are compensating by spinning all the time. Its normal in a turn to have those gears spin on a open axel but just driving down the highway it puts more wear on them when they should be doing very little. The power divider will also wear out as the rear axel may be slower than the front (or vise versa). the Divider components will try to compensate for the speed diffrence and wear early as they should not be needed when driving down the highway. I notice some old macks can spin all 4 corners in the mud on a rebuilt tight drive line where worn out rears will spin 1-2 wheels and the powerdivider may not lock in as it should. Herb, please Correct me if im worng but with macks power divider you only get 2 drive wheels "locked" in? One wheel on the FR and the other on the RR axel? With a diff lock and power divider you should have 3 wheels locked in? Trent

looks to be geared for 55-60MPH depending on the overdrive ratio. HP in that range will pull fine on the flats but you will be downshifting in the hills. the 250 HP thermodynes did good for there time but the maxidynes soon took over.

nice pics John. I really like that old dog. Whats with the new weight laws in your state?

I converted my RS700L from manual to power sterring. I had to locate a pump,sterring box, resivor and lines. also needed a diffrent sterring shaft as it was to long or short with the new power steering box. I had to drill a few holes in the rail to mount and make a few large washers to get it flush on the frame rail. Not a bad job to do one weekend. Trent

and at that rate just keep it stock as the 12 speed was one of the first Mack air shift boxes that worked well. One thing I have never heard was if the clutch packs were better on the 12speeds vs the 9 speeds

FJH will know more about the problems in 04 but if I recall low power, Elictrical issues and Turbos? Turbos were on back order all over the place> I recall many had to wait 2-3 weeks to get a reman turbo. Many Mack Shops would over stock them if they cold get their hands on them and try to keep them off the "system" so they would have them in stock to support the local owners. It was not a mack problem but the turbo MFG was making them look very bad with no spare turbos. Electical troubles, Derate, trucks just shutting off, Not good and around here,lots of old mack owners went to other truck MFG soon after. Low power from emission issues. the engines would just start to come alive and pull then you had to shift. No throttle responce. it was like driving a large truck with a gas engine... this was my experince with the 04 models

I had mack boots about 10 years ago. I had both the black and tan leather. came in a green/black and red box had the old Mack logo with the "correct dog" on the emblem. they also lasted me 3-4 years before they were worn out. I used them every day at UPS working the docks walking on steel grates. Havent seen the new boots

hmm. on all the air lock power dividers I have used all you had to do was get some slack in the drive train to have it release. If I had it in and was going through mud then exit on to a street, the PD would unlock as soon as I let off the power or the truck coasted a little.(switch in the off position) Backing up will also do the trick but I have never had to as long as I unloaded the stress on the drive line and was not in a turn.? most times I turned it off 10' before I hit the pavement unless I needed it to get out. A few rules I have learned and told about with air power dividers..... never put it in with the tires spinning Most times the truck should be stopped or rolling in a straight line at slow speeds to put it in. dont drive on pavment with it in turn off before you reach hi speeds. dont put in at high speeds. tire size across the axel is important but hurb had just pointed out a great example that I did not know about mack power dividers.(thanks Herb)

Lets see. 1st you have the hi lo range shifter that is used with the clutch packs then you have the Low Low "dash switch" to use the lowest gear in the box. then you have the Reverse sshifter. all of these would have to be figured out in the shift pattern. Even if you removed the clutch packs you still have to find a way to get all the gears to slide around to enguage or not enguage. Money talks but its not really worth it to get 2 sticks from it as it works pretty darn good as it is. I always say its one of the best boxes Mack ever put behind a maxidyne.

10-4 fred. The 440 V8 at the yard holds around 26-28PSI. I think its a 1991 model? on a good pull I figured it should be close to that psi?

at one time the gold dog was to show the truck was 100% Mack drivetrain. I think that changed in the mid 80s? I herd Recently it has been brought back to represent a 100% mack drive train?