TripleTreeThomas Posted July 6, 2020 Share Posted July 6, 2020 Hello, thank you for sharing this excellent for with me! To start off, I am almost totally ignorant when it comes to Mack but have experience with other diesels, multifulers, and gassers. Recently while looking for a car hauler I came across a 1961 B61 mack that was converted into a roll off tow truck. The seller told me that it has a 6 speed and a thermodyne engine which tops out at about 60 mph. Here is where my questions come in: 1. Can you get a Thermodyne and a 6 speed or is he mistaken and the engine is a Maxidyne? (I have not seen it in person yet as it is a bit of a drive to get to) 2. Seems pretty easy to change the rear end or gear ratio to get somethingmore freeway friendly. Is this something that the engine and transmission can handle? 3. Other than the obvious hard starts, white smoke, blowby, fuel or coolant contamination in oil, knocking and other odd noises what else should I be looking for? Thank you again! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/ Share on other sites More sharing options...
carlotpilot Posted July 6, 2020 Share Posted July 6, 2020 (edited) that old horse looks really good in the pics. if he`s not looking for both arms and one leg for it`it could be a keeper. I`d say say go look it over thoroughly for rust & such. as you said power & running gear can be changed . & welcome to the forum also not likely a maxidyne . trans could be a duplex 5x2 mistaken for a 6 spd. Edited July 6, 2020 by carlotpilot 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455160 Share on other sites More sharing options...
davehummell Posted July 6, 2020 Share Posted July 6, 2020 If the cab assembly is pretty good you can really get it set up to your needs without to much fuss and money. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455170 Share on other sites More sharing options...
Ditchdiggerjcf Posted July 7, 2020 Share Posted July 7, 2020 Pretty dang nice, and I am not a B guy. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455205 Share on other sites More sharing options...
TripleTreeThomas Posted July 7, 2020 Author Share Posted July 7, 2020 Thank you for the replys. He is asking 10k for it. Told it is a turn key ready to drive home truck. Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455210 Share on other sites More sharing options...
david wild Posted July 7, 2020 Share Posted July 7, 2020 I like it, you should buy it and if you don't like some one here will buy it from you. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455211 Share on other sites More sharing options...
carlotpilot Posted July 7, 2020 Share Posted July 7, 2020 (edited) 26 minutes ago, TripleTreeThomas said: Thank you for the replys. He is asking 10k for it. Told it is a turn key ready to drive home truck. from outward appearance I`d say it is Edited July 7, 2020 by carlotpilot 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455213 Share on other sites More sharing options...
mattb73lt Posted July 7, 2020 Share Posted July 7, 2020 On the cab, check the driver’s side floor area. Both door sills and door bottoms. Check along the cab floor where it meets the back wall of the cab, inside and out. The cab back wall is prone to rust in that area. Fenders can be replaced/repaired. Door jambs and gutters. Windshield and upper cowl areas are other areas to look at. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455282 Share on other sites More sharing options...
mattb73lt Posted July 7, 2020 Share Posted July 7, 2020 When you inspect it, try to determine what has been done to it and modified over the years. Any mods done well and with the right components should be OK. Wiring is not a huge deal, as the electrical system is simple, harnesses available and you can make your own without too much difficulty. Stay within you capabilities for doing things and you should be good. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455283 Share on other sites More sharing options...
mrsmackpaul Posted July 7, 2020 Share Posted July 7, 2020 Is it possible to have a Thermodyne with a 6 speed Yeah of course it is Is it drivable like that ? For sure amd especially considering it's only a small truck it should be more than fine When and if you go for another look Just gran some photos of the engine and any plates on the engine Get undernearh and take a quick picture of the transmission With this basic information we on here should be able to tell you pretty much what you have As in duplex or maxi torque Grab a picture of the plate on the injector pump as well if you can Plenty of help on the forum will be forth coming Paul 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455285 Share on other sites More sharing options...
TripleTreeThomas Posted July 8, 2020 Author Share Posted July 8, 2020 Went to go look at it yesterday.... the cab had lots of rust around the front windows, driver's side cab corner and a bit in the passenger door. Not terrible but not great either as there was lots of bondo covering other parts of the cab. Passenger door fit terrible. The wiper motors and hardware was missing and the holes were silicone shut. The rear diff was puking out gear oil from the pinion seal and had a lot of vibration above 45 mph. Not too big of a deal because I would want to replace it with something a bit higher geared. Drive shaftvm and U joints were all brand new. King pins had a bit of play in them but I did not notice unusual tire wear or steering issues. Engine was a maxidyne with a 5 speed duplex. Shifted as expected (double clutch every gear), the engine had minimal blow by, some oil seepage but nothing bad. Steered well, stopped great. The wrecker bed has several issues but still functioned OK but not completely safe and not completely dry. Had a few air leaks nothing too difficult to fix. Tires are old, 5 out of 6 seemed fine. Guy dropped his price to $7500 pretty quick, I am stuck at $6500 just incase the rear diff blows up on the 3 hour (at 45 to 50 mph) drive and I need to hire a medium duty wrecker to take it rest of the distance. Thank you again for the educated replies. Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455330 Share on other sites More sharing options...
mattb73lt Posted July 8, 2020 Share Posted July 8, 2020 From what you found, $6500 doesn’t seem too bad. The cab sounds like it has some issues. But, if you think it’s within your capabilities and you have the ability, you should be ok. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455335 Share on other sites More sharing options...
Popular Post mrsmackpaul Posted July 8, 2020 Popular Post Share Posted July 8, 2020 I try and stay realistic in my head when buying treasures I look at things that hopefully look crap and I almost always buy things that most others would pass on Everything will wear out and I prefer to rebuild it myself as I then know what short cuts I have taken It is a truck and a old truck and I would be more concerned with buying it if it all looked Micky Mouse as I would have no idea what secrets its hiding If it is a Maxidyne and Duplex you have a box that isnt really strong enough for the torque that motor will make As I said before, just a quick glance underneath will show if its a tripple counter shaft transmission or not Three caps laid out in a tri angle pattern and a triangle shaped box 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455352 Share on other sites More sharing options...
mrsmackpaul Posted July 8, 2020 Share Posted July 8, 2020 A Maxitorque from the rear A Duplex from the rear 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455354 Share on other sites More sharing options...
terry Posted July 8, 2020 Share Posted July 8, 2020 1 hour ago, mrsmackpaul said: I try and stay realistic in my head when buying treasures I look at things that hopefully look crap and I almost always buy things that most others would pass on Everything will wear out and I prefer to rebuild it myself as I then know what short cuts I have taken It is a truck and a old truck and I would be more concerned with buying it if it all looked Micky Mouse as I would have no idea what secrets its hiding If it is a Maxidyne and Duplex you have a box that isnt really strong enough for the torque that motor will make As I said before, just a quick glance underneath will show if its a tripple counter shaft transmission or not Three caps laid out in a tri angle pattern and a triangle shaped box The duplex will hold up on a hobby truck, just no lugging or heavy hauling with it. I ran a 237 in front of a quad for years, with no problems, but i was the only driver. terry 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455365 Share on other sites More sharing options...
Popular Post mrsmackpaul Posted July 8, 2020 Popular Post Share Posted July 8, 2020 Yes but I guess when you dont know the history its different and to be considered If it had for example a 300 Maxidyne and had pulled a lot of heavy loads in the past it could be a different story None of these things are deal breakers to me but rather just things to consider thats all Paul 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455380 Share on other sites More sharing options...
TripleTreeThomas Posted July 8, 2020 Author Share Posted July 8, 2020 2 hours ago, mrsmackpaul said: I try and stay realistic in my head when buying treasures I look at things that hopefully look crap and I almost always buy things that most others would pass on Everything will wear out and I prefer to rebuild it myself as I then know what short cuts I have taken It is a truck and a old truck and I would be more concerned with buying it if it all looked Micky Mouse as I would have no idea what secrets its hiding If it is a Maxidyne and Duplex you have a box that isnt really strong enough for the torque that motor will make As I said before, just a quick glance underneath will show if its a tripple counter shaft transmission or not Three caps laid out in a tri angle pattern and a triangle shaped box Everything is Mickey Mouse on the truck. Lots of non penetrating booger welds, wiring using house wire nuts, or just electric tape or no insulation at all, dash is drilled full of holes with unlabeled mismatched toggle switches with out a fusible link, soft bolts where grade 8 or higher is called for, bondo a couple inches thick in places, steering wheel not properly aligned (pet peeve), lots of corners cut, very amateurish work. I dio not remember what the transmission looked like. It is about 75 miles away from me. Did not realize that there was more than one 5 speed duplex transmission but then again my knowledge of Mack is very limited (why I am here). The transmission shifted nice, did not pop out of gear, whine, etc.. but I was unable to float the gears well so I just doubled clutched every shift up or down. Which gets old. Could be more my lack of skill with this transmission/engine/gear combo than the machine. I would not pull heavy with it. Just haul a car or truck on the back of it on occasion. I will but it if he meets my price just because I like the way the truck looks, smells and sounds. Not the most logical way to buy things but if I am throwing my cash at it, it helps to like it. Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455384 Share on other sites More sharing options...
mattb73lt Posted July 9, 2020 Share Posted July 9, 2020 Ok, but don’t fall in love with a headache. You’ve listed a lot of issues in your last few posts. As I’ve said, you’re the one who will work on it and expend your hard earned money to make it what you want. From what you’re posting it starting to add up to a lot of work. I would proceed with caution and I would be looking for a little less to purchase. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455385 Share on other sites More sharing options...
carlotpilot Posted July 9, 2020 Share Posted July 9, 2020 well I hit 1 out of 4 - it could be driven home - good luck with it if you go that route 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455387 Share on other sites More sharing options...
h67st Posted July 9, 2020 Share Posted July 9, 2020 4 hours ago, mrsmackpaul said: Is that a triplex? My TRD720 (9 speed OD) has one lever in the top cover and the hi-low shaft on the right rear like this photo, but I see this one has two levers in the top cover. Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455391 Share on other sites More sharing options...
mattb73lt Posted July 9, 2020 Share Posted July 9, 2020 It's a duplex. Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455393 Share on other sites More sharing options...
Ditchdiggerjcf Posted July 9, 2020 Share Posted July 9, 2020 3 hours ago, TripleTreeThomas said: Everything is Mickey Mouse on the truck. Lots of non penetrating booger welds, wiring using house wire nuts, or just electric tape or no insulation at all, dash is drilled full of holes with unlabeled mismatched toggle switches with out a fusible link, soft bolts where grade 8 or higher is called for, bondo a couple inches thick in places, steering wheel not properly aligned (pet peeve), lots of corners cut, very amateurish work. I dio not remember what the transmission looked like. It is about 75 miles away from me. Did not realize that there was more than one 5 speed duplex transmission but then again my knowledge of Mack is very limited (why I am here). The transmission shifted nice, did not pop out of gear, whine, etc.. but I was unable to float the gears well so I just doubled clutched every shift up or down. Which gets old. Could be more my lack of skill with this transmission/engine/gear combo than the machine. I would not pull heavy with it. Just haul a car or truck on the back of it on occasion. I will but it if he meets my price just because I like the way the truck looks, smells and sounds. Not the most logical way to buy things but if I am throwing my cash at it, it helps to like it. Having to unfook everything the idiot that had the truck before you did is SOP around my place. It usually takes a minute. Some of the stupid things they do are quite ingenious and difficult to spot without serious scrutinization. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455404 Share on other sites More sharing options...
mowerman Posted July 10, 2020 Share Posted July 10, 2020 Sounds like you definitely fell in love with a headache ha ha Ha sorry but there must’ve been something about it you liked I did appreciate the pet peeve crooked steering wheel caper . I would have to fix that first have a ball with it my friend and welcome aboard..... bob 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455521 Share on other sites More sharing options...
TripleTreeThomas Posted July 11, 2020 Author Share Posted July 11, 2020 6 hours ago, mowerman said: Sounds like you definitely fell in love with a headache ha ha Ha sorry but there must’ve been something about it you liked I did appreciate the pet peeve crooked steering wheel caper . I would have to fix that first have a ball with it my friend and welcome aboard..... bob When I was a kid I had a bad habit of bringing home the 3 legged, blind dogs that I would find. Now I cannot pass on unique old beaters when I find em cheap. Guess it is hard to pass on personality. Thank you! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455548 Share on other sites More sharing options...
mowerman Posted July 11, 2020 Share Posted July 11, 2020 well thats all the more fun you will have straitening out all the issues,,,,i guess after all,isnt that why where all here???????????stand back,and and admire all your efforts and improvements...besides you definately didnt pay too much,,,,,oh i like your handle by the way....bob 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63187-to-buy-or-not-to-buy/#findComment-455567 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.