jimtruck

'83 R686 with a E6-300. When driving and trying to maintain a constant speed, say 50mph, the engine is constantly "hunting" or surging. Linkage/ Throttle arm look good and feel ok. I removed the governor assembly from the pump and disassembled it, nothing seemed abnormal or wore out. Is there anything in particular i should look for? The gear that drives the governor has what looks to be a slip clutch on it, What is the proper way to set it? The truck idles ok and pulls good with plenty of power, its just hard to drive due to the surging and it gets worse with light to no load on the engine. The pump is an American Bosch type APE6bb110T6978. Thanks, Jim

I'm getting ready to start working on my b-75. It has a regular B model cab on it, which is a tight fit for me. I was curious if an L model cab would fit on this truck...I've seen a few B models with L cabs on them and like the way they look. Is it doable without changing fenders, hood, etc? Just looking at my options before I start into fixing this one up. Thanks, Jim

Thanks for the replies How many things do you have to change to drop that engine in there? All the mounts and tranny bolt right up? Clutch parts interchangeable? Thanks, Jim

I'm pretty good at not hot rodding equipment, and the truck wont be used every day. It will see the occasional heavy load, but its mainly going to haul the occasional backhoe/mid sized crawler. If I were to shift it like it still had the 711 in it...not skipping gears... would the tranny hold up for a while, or is it a guaranteed death sentence? Thanks for your help, Jim

I've finally been able to start driving my truck around a bit and have discovered that the 711 has got a knock at idle. I narrowed it down to the #3 cylinder. The injector and valve lash are correct and the rack s in the pump are correctly timed. Since the 711 already has a bad rep, I've decided to start looking for a different engine to swap in. The truck is a '64 b-75 and its going to haul various loads with a low boy trailer. I'm not going to be using it every day, but it will get used,,,if that makes any sense. I also want to keep the triplex transmission. What do you all suggest? I've heard good things about the 237 and the 673c on this site. I just want a good reliable engine that I wont be afraid to drive.

Can anyone get me a Napa filter number for my End711 in my 64 mack b-75? If you all prefer filters other than the Napa, I'm open to suggestions. Its got the large canister filter on the driver side of the engine. thanks, Jim

I found out that the Third Axle Air valve is blocked off. I checked my factory build sheet and found that my truck never had a power divider. I don't know why the switch is there, but it definitely has been blocked off for a very long time. The truck tractor protection valve works, and sends air to the trailer hoses when flipped.

Here's those flip valves

Thanks for the replies! BC Mack, that Bendix site will be helpful-thanks. Does anyone have an air line/valve plumbing schematic for these trucks? This truck has been cobbled on and a schematic would be helpful to me. I'm going to try and put Maxi brake chambers on the back axle, so any advice there would be welcome. Ive already got the chambers, and I believe that I can make them fit.

I've finally got my truck running! My next order of business is to get the brakes working. I'll go ahead and admit that I don't have any experience with air brakes or their controls. Inside the cab, I have a " Air 3rd axle loaded/no load" , "Truck tractor protection" , and a rotating valve that has "run-park" on it. There's also a lever on the steering column that says "not for parking". To show my ignorance, I have no clue what these valves are supposed to do. If you guys could shed some light on this for me, I'd be grateful. My truck has the camelback suspension. are both the axles supposed to drive all the time or is there supposed to be some kind of shifting mechanism to engage the rear axle, as I don't see anything back there except the brake air lines. Thanks, Jim

I'm working on getting my B-75 with a end711 running. It has had a turbo added a long time ago. Ive heard that when you add a turbo that your supposed to replace the syncrovance with a regular coupler. I don't have access to a regular coupler, and was wondering if I could disable the syncrovance so that it didn't change the timing. If so, what position should I disable it in, I assume that it should be left in the Non-advanced position. Thanks, Jim

Here's some pictures of my new truck!

Thanks for the quick replies! I just didn't know if the head gaskets could possably be failing due to lack of coolant flow. I'll just have to run it and see what happens- I doubt that I'll work it hard enough to cause it any problems. I just like to know a machine's strengths and weaknesses before I go about using/working on it. Thanks, Jim

I'll try and post pictures later today. What if I were to drill a few holes in the thermostat or just remove it all together to keep a constant flow of coolant through the heads? Ive done that on a few old tractors, but this is a bit different than a Farmall H!! Thanks for your replies, Jim

Hello everyone, I'm new to the forum and new to Mack trucks. A 1964 B-75 recently found home in my barn, and I'm in the process of getting it running. My plan is to fix the truck up and use it to haul around the miscellaneous equipment that I come across. Its not going to see everyday use by any means, but I would like to be able to get it out and use it like it was intended to. The truck is equipped with a ENDL 711 with the added turbo and the transmission is a triplex. This engine has the heads with the large bolt (I think its 3/4) on the drivers side front and rear corner of the head. It seems that everywhere I look, there is talk about headgasket issues with this engine. I havent got it running yet ( injection pump problems) but if it runs good, I'd like to keep it in the truck. My question is, is there anything I can do to prolong the life of my headgaskets? With the triplex, I'm guessing that I wont have any trouble keeping my rpms up to avoid lugging. Are these gaskets failing due to excessive heat? Do the head/block deck have warping issues? Am I going to need to keep a spare set of gaskets in the passenger's seat? As I said, I'm new to Macks so forgive me for any dumb questions. This forum is a wealth of information and I'm very happy to have found it. Thanks for the help, Jim