new to Mack and this forum

[deadparrot]

Hello everyone. New to the Mack family and this forum. When I was a child I always thought the big mean looking Mack trucks I saw crawling around the timber lands of Wyoming were the best thing ever. Now as an adult I finally get the chance to buy one for a project with my kids. We have always ran the old Ford power units on the farm so this is a whole new world for me.

 

Ill be posting pictures soon when I get her home. Title shows it as a 1980 Mack, and thats it. The vin is u685st19543 and matches the door plate. Door plate also shows Allentown PA. Only the vin is stamped. Everything else is blank.

I believe this to be an U, but thats as far as I can come come up with and thats simply comparing it to pictures in google. The cab is offset. So my understanding is this is an R series, U model. Being shorter than the R and an offset cab.

Anyone have resources they can point me to in order to decode the vin? Also looking for shop manuals so I can start wrapping my head around this Mack platform.

 

Cheers everyone

Edited January 17, 2021 by deadparrot

[85snowdog]

Welcome aboard and congrats on your new to you "U" . 

There is a lot of good info and helpful people here. 

Here is a useful link to some info on VIN numbers.                                                                                     https://www.bigmacktrucks.com/topic/51420-r-model-vin-decoder/?tab=comments#comment-382830

If nothing has been altered, you have a U model tractor with tandem wheels. A Maxidyne 237 engine that is absolutely bullet proof. 

I think most 237 's were backed with either a 5 speed or a 2 stick 6 speed tranny . But could be wrong about that. 

 

You will have yourself a cool project . Hopefully you post lots of pics . 

 

 

 

 

[Joey Mack]

Mabey you can find one of these... The Mack 107 tranny book is around too... Good luck, Great find.. jojo

[deadparrot]

3 minutes ago, 85snowdog said:

Welcome aboard and congrats on your new to you "U" . 

There is a lot of good info and helpful people here. 

Here is a useful link to some info on VIN numbers.                                                                                     https://www.bigmacktrucks.com/topic/51420-r-model-vin-decoder/?tab=comments#comment-382830

If nothing has been altered, you have a U model tractor with tandem wheels. A Maxidyne 237 engine that is absolutely bullet proof. 

I think most 237 's were backed with either a 5 speed or a 2 stick 6 speed tranny . But could be wrong about that. 

 

You will have yourself a cool project . Hopefully you post lots of pics . 

 

 

 

 

Thanks for the response. It is a five speed the best I can tell. Or at least I could shift into five slots and I could not locate a splitter and it did not have a second shifter. 

Hoping to find some shop manuals for her. Cant wrap my head around Macks naming and numbering system yet.

We are putting batteries in her tomorrow to get her home. Only 57000 original miles and the engine looks super clean. So im hoping she is solid mechanically. 

[Joey Mack]

the 105 is very basic, and bullet proof... triple countershaft.. just be patient shifting it... it's no Eaton.. Jojo

[deadparrot]

5 minutes ago, Joey Mack said:

the 105 is very basic, and bullet proof... triple countershaft.. just be patient shifting it... it's no Eaton.. Jojo

Is it a 105 or 107 Jojo? You said 107 in your first response and now 105. Maybe I missed something. Sorry, im trying to learn here. Thanks for the response sir.

[Joey Mack]

it's all good... i was guessing what you had, when you said 5 spd. i said 105.. The Mack  triple countershaft tranny's, were the same in the main box... the added back box changes it up,,  with a few exceptions... Jojo. Hope I cleared it up sir..

[Joey Mack]

I really wish I was there to see it, and hear it fire up!!!!  Jojo

[tjc transport]

as Jojo said, take your time shifting. this is not going to be like most multirange transmissions where you snap gears. 

these mack 5 speeds are slow shifters. as i used to tell my guys, pull it out of gear, take a nap, and when you wake up slip it into the next gear. 

with that 237 5 speed, run it up to 2100 rpm, slip it out of gear, and it should fall into the next gear around 13-1400 rpm if i remember correctly. 

also if it has been sitting a long time, loosen the air intake and have something handy to plug up the air intake in case the fuel pump sticks open. i have seen a few run away when firing up after sitting a long time. 

[Joey Mack]

When I was driving late 70's R models, I learned to count, One One thousand,,,Two... I would double clutch,,, Then On "Two" I would grab the next gear.. It still works for me today... I rarely get to drive a 107 or 2070 anymore.. In youre case a 105.... same-same... Jojo

[deadparrot]

I clearly found the right place for help. Ill record my first start for you guys. I have so many ideas for this truck lol.... when I had free time away from the farm before I rebuilt/restored Harleys. So my creative side is going a bit crazy with this rig. But I need to wrap my head around the mechanical side of things first. Im just glad its not a 5+2. I can handle slow shifting, but I swear you have to be a witch to shift a 5+2.

I dont know if I let my inner kid go wild with big stacks, headache rack, and bumper the size of a Buick. Or just clean the old girl up with some fresh paint and new shoes. Take her to the local elevator for all the old timer farmers to gawk. So many paths.

Thanks for the warning on firing her up. Ill be spending time with her on the farm lot before going down the road. Wouldnt be the first piece of equipment to go through a barn here HAHA...