Can Of Worms!!!!

with a 9 speed you will want them low gears. You wnt low gearing for off road work. lower the better. Of course the best thing would be a deep reduction tranny but you'r $20k will limit what you can get.
My uncle is a logger and he will only run macks. His son has some KW's. these days it's a wash I guess since Mack isn't what they once were.

 

R Model Mack. Think R685ST or R686ST. Try to get a 2 valve engine, and a TRL107 or TRXL107 trans. Mack 4.17 rears on Mack Camelback suspension.

With even slight care, that truck will still be running when we are pushing up daises.

I take it you are hauling pulpwood for paper? There is one for sale in Bristol Fl.
I'll bet you can buy it for 5 or 6 G

 

I have seen that mack camel back do things offroad I never thought possible. I drove a rollback truck with one and it went through stuff I wouldn't take my offroad jeep into.

 

Yeah that was back when a Mack was a MACK. I am starting to see a lot of R Models around. The South American export market for them has picked up again too.

If you want a good bulletproof one, Get one with an ENDT675 or Endt676 Engine. Look at the pump, you want one with an American Bosch APE 6BB110T pump. Robert Bosch would be a good 2nd choice. Try to stay away from the American Bosch or Ambac PLM pumps. The PLM pumps were a little weak in the cam followers. If you turn them up much the rollers wear right out.

You want a 5 or a two stick 6 speed trans. Stay away from the Mack 2090 trans or any of the other 20 series trans, the syncro in the back end of them always went bad.



It's a shame what happened to Mack. They are pretty much a re badged Volvo now.

 

The 350 engines were ok but a 300 Maxidyne will run right along side one and using only 5 gears. the 350s and 400s needed at least 9 gears.

The 2 most desireable engines are the ENDT 675 (237 hp MAXIDYNE), The ENDT676 (300 HP Maxidyne) as far as the later 4 valve engines go the EM6-300 Maxidyne was about the only good one.

The Mack Maxidyne engine had a very wide powerband that is the reason it can run with only 5 gears.

With a slight fuel pump recalibration, even the 237 HP Maxidyne will run right along with anybody elses 350s and 400s.

I once had a 237 that put out 375 HP on a chassis dyno.

BTW are you running over to PCA Valdosta with that wood?

 

I get SO lost when we start talking Macks. They were a creature all there own and have so little knowledge of them.

My uncle is so unhappy with the macks he has had in the last few years I don't expect to see many more around. he's had them back to the factory looking for problems they never could find. They never used to have problems with them and now they can't seem to keep them running

 

There is a reason you see o many mack dumps, log trucks, etc. they are the undisputed off road champions. with the roll offs I mainly drove a volvo heavy chasis th eother guy had a mack and even with his differential lock not working he could get further into the landfill after a rian with one axle than I could with both. I don't know what it is with that suspension but it works.

I'm more familiar with the ten speed with the deep reduction, and the 15 speed but we had a "loaner DR mack with a 5 speed and I hated that darn thing. It was god in the landfill but if you had to go on the road it just didn't work for me. then again it had no shifting diagram and it was some wierd thing like 3 on the bottom side and two on the high side or soemthing. Never did figure it out right