burnin oil

I confirmed that the box is a Gemmer 500s. Does anyone have a repair manual on this thing? I have the Mack adjustments sheet but nothing on setting the bearing preload (shims) when doing a complete tear down. If anyone can help me out I would appreciate it.

Sounds like they are wore out. If you have play it is going to let the rear walk around at speed.

Thanks Bob. It is an LJT. It looks alot like a Gemmer according to the adjustment procedures I found on another side. Now I just need to find a repair manual and parts and I am set.

Does anyone know who made these boxes? I have alot of in and out movement of the steering arm and want to rebuild the box. Everything feels good other than the excessive slop, about 4"s at the steering wheel. The exploded view I got from the Mack museum looks pretty easy to work on other than figuring out what parts I need.

My single axle L model with a PTO winch (heavy) was 14,800lbs on the scale. They may be a little heavier than you think.

Thanks for looking.

Mine hits the air cleaner every time since the limiting rod doesn't appear to hook to anything inside the door.

That would really be helpful to me also if you come across it. I am doing my truck as a rolling restoration. Get it road worthy then do body work.

I would have to dig up the part numbers but I saw brand new 24.5" accuride demountable rims for $100 a pop. I am just starting to lok for tires myslef to replace the 11r22's on the truck.

If it has a good break down of compoents I would be interested also. The Mack Museum sent me a wealth of info and alot of build info but it means nothing to me without a way to tell what it is. Those exploded diagrams can be a life saver when trying to figure out how to tear things apart.

Spicer 7041. Pulled it out of an old Reo.

Dodge 5500. 4.44 gears and a 6x4 trans. Added a pic of the trailer when the LJT was coming home and crossing the scales at Sadler Bros Truck Stop. Sorry you cant really see the Dodge in that picture. Its in the gallery under 1951 LJT.edit.. found another pic I posted on the net before with the 5500 in it.

You need new mech! Smacking the tank to get the fuel pump to work is on par with hitting a starter with a hammer when the Bendix is dying. It will get you home but pretty soon it wont.

I picked up a trailer like that for my Dodge. I converted it to electric brakes and 4 new tires (of 8) and have a total of $3300 in it. Trailer was made by Fairie around 1980 (can't remember off the top of my head). Works good for hauling my Mack.

Thanks Rob. I knew about the roadranger bell. I actually have a SAE2 housing and 1 3/4" input for a RTX-14607 transmission at the house. I got the trans for $100 and may stick it in a Dodge 5500. Truck already has a Spicer 7041 mounted behind the Tcase. Then again I really like the idea of a RTOO 13spd. If I have problems with the END in the L model I think a hopped up 5.9 Cummins is in the future. Alot easier to run it at higher speeds and not worry about rearend gears. My little 12v makes more tork than the 673, alot more!

Rob, out of curiousity are the bells interchangeable on the transmissions? Like putting a SAE2 on a diesel transmission. Might do a repower one day.

6041 has a 2.14 1st gear. Should be a nice little setup. My Dodge 5500 has a 7041 with a 2.30 low gear and it is the best thing going when slow manuvering.

Get a SAE2 housing for a 5.9/8.3 Cummins and you should be in business for pretty much anything rated at less than 1200ftlbs of torque made by Spicer, Eaton or Clark. Now mating a Cummins to a Mack trans may be a different story because I do not know if they ran a SAE housing or not.

Thank you.

If you post it I would love to have that info. When I redid the rear brakes I found a cracked spoke on mine. Hard telling how long its been that way because I didnt see it until hour six with the pressure washer and oven cleaner!

If so post it up. I am going to start mine here soon.

Unless you are towing alot or working in fields I would just get a 3spd aux. No need to spin that huge deep reduction gear around all the time. Also you will want to look for a tight ratio aux if you are using a 5spd main. In my 5500 I have a 6spd main with a 4spd aux and the ratios are way to close to work all those gears realisticly. I usually just shift 1L, 2L, 3L, 4L, 4D, 5D, 5O (when really heavy), 6D, 6O. Sometimes I will use another cog but that has to do with the speed limit I am towing at and not the pulling power of the truck. I picked up a Spicer 7041 out of a Reo for $200 and mated it to a G56 trans. Cat vs Cummins. Cummins all day. Find a PPump motor and 600HP is an easy day for it without breaking the bank, not to mention 4k RPMs!

Actually there is a Mack jr hub cap on Ebay right now. Supposed to be original and looked pretty good in the pic. Out of TX for $200.