Lmackattack

forgot about some of the cummins. but they are still pretty rare. A few superliners I drove had Cummins but had eaton trans behin them. only seen one cat powerd mack in person. but this is Chicago and in its day it was all mack or nothing.

looks like the TRQ7220 has a 13.8ratio in the lowest forward gear 1st LO LO and 6.52 1st low split. a quick search here found an old thread by "block" with this message " Mack made 2 different 2 stick 6 speed Transmissions. the first one part number TRXL 107 had the following gear ratios. Low range 14.10 in first, 8.20 in second, 4.65 in third, 2.72 in fourth, and 1.64 in fifth. High range as follows 8.59 in first, 4.99 in second, 2.84 in third, 1.66 in fourth, and 1.00 in fifth. And the following ratios in reverse. 36.66 in first, 21.32 in second, 12.11 in third, 7.07 in fourth, and 4.27 in fifth. The second was part number TRXL 1071 The gear ratios in low range are as follows 23.08 in first, 13.42 in second, 7.62 in third, 4.45 in fourth, and 2.69 in fifth. The gear ratios in high range and reverse were the same in both transmissions. There were also air shift verisions of both transmissions part numbers TRXL 107A and TRXL 1071A. Hope this helps out Blocl" looks like the quad with 4.17 rears in 1st LO LO would crawl at 3-4MPH at full throttle? a 6 speed in LOW LOW 1st is 3-4 mph also. At that point I would be more concerned at the stress the trans would see in that gear with the maxidyne. Ok I did my part. we need solid numbers to move forward... Who is good at math LOL!!! Trent

thats a very nice Truck. looks better IMO also..I sure hope it works out better for you. post up some pics after you get it home. Trent

his only saving grace is that he has a maxidyne to pull the now faster low gears. I think even at 10 tons he may be safe in the LO LO range of a quad even in slight off road conditions. We need to figure out what a 5/6 speeds first gear is with 4.17s and compair it to his first gear with a quad and 4.17. I dont have ratios handy to compare

45MPH at 2100RPM with 22.5 tires of a 42" dia with a final trans OD of .73 33MPH with a direct drive is this a gas engine? if it is @2500RPM with .73OD you have around 54MPH

I havent heard of a factory mack truck built with a mack trans behind an off breed engine but I guess it could be true? i would think you need to use most of the 12 forward gears to keep the cat in its power band?

you will be fine if you drive it the right way. if the quad is double overdrive you will have a geared top speed of around 100MPH tho LOL

The Trucks have a singel LED under the cab and have Fiber optics to the head lights and cab roof. The Trailes have 2 Leds one for red and the otherfor amber. The mixers have the led hidden under the drum. all have to be hard wired. I have about 5 R model Mixers, 3 R model with doubles and a few with 40' trailers that I will be listing soon. If anyone is intrested drop me an email and I will sell direct. I also model in HO scale also. I have a small layout at home and belong to this club http://www.emrrc.org/ Its one of the largest in the Chicago aera. Some of us will run 100+ car trains without any trouble of holding up the other members on the layout. its basicly a 2 train mainline with a few spots of single track. I do alot of scenery work over the winter months when things slow down. Heres a few vids of the trains I run down there. http://www.youtube.com/watch?v=IA28-zblCm8&feature=related http://www.youtube.com/watch?v=vqBgNLUQQBQ Guess my secret is out now...Im a train dork also LOL Trent

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?