Lmackattack

you dont have boost! 22 psi is a low side I think 25-30 would be what you shoul see. My straight 6 285 will pump out 28-30PSI in the cold. this is with the pump turned up a little.

I have yet to see a air shift 12 speed converted to a 2 stick. I dont think they were ever set up for manual linkage so it wont work. The older 6 speeds had the shift cover do all the work in the aux box so it could be manual or air depending on the cover you installed. I like 2 stick transmissions but I think the 12 speed with its clutch packs and short splits that work the aux box is beeter suited with air. let us know if you find more info on this...

I like how steep of an angle I can get my frameless and never have to shovel stuff out but then again always liked the safty factor of the 1/4 frame. as long as I dont have a frame trailer ,,Im all good.

if that pin broke that will be the first place to start. depending how long its been broken will depend if it wore down the pads and trunion bushings

I see one small problem.. We need a few pics of this project!!!!

It can be a number of things Worn pads, worn trunion bushings can cause the rears to walk. also bad control rods can add to them walking more. do the springs slide side to side? It could also be a bad end cap that has let a spring wear into the metal. The 2 control rods (one from the top of each diff housing to the trunion/crossmember) hold the diffs upright and control the torque input from the driveshafts. the 1 control rod on the rear rear diff is there to help hold the axels from walking. All the trucks I have seen had only one of these rods and it was on the rear rear axel. If this rod is worn out it will also cause the axels to walk. that rod was intended to help keep the axels in place on hard turns. Trent

I need to get my Dump trailer painted but I need to get the sides up about 6" I Figure I should add the sides first before I go and blast the traler for paint. looking for a 6" tall / 3" wide by 20' long. could be in 10' sections but need a total of 40' prefer used as its cheeper. can have some dents as it will get beat up anyways. if you are close to Chicago and know of any let me know. Also been thinking of finding a used 36" ablebody sleeper to put back on the truck. Mine had one from the factory but someone removed it years ago.. a few winter projects for me.... let me know Thanks Trent Chicago IL

wow .. thats a project LOL!! i wish you luck with it. thats alot of things to get lined up right. It sounds like you will be better off making some of the mounts rather than trying to get the diffrent parts to work for you??? regards Trent

If I recall correctly a R700 mount is a little diffrent than a 73+ RS700 mounts. as the later RS cabs sat higher above the fram than early models. same with Valueliners as those cabs also sit higher. As rob said the RS600-valuliner and later RS700L all had straight rails. the diffrence could be the mount or where the mount holes were drilled. I think most of the later cabs used the same style but they could be a little diffrent depending on the model of the truck. simple way to check cab hight is to look at the back of the cab. if the cab rear wall is about flush with the top of the frame rails. that could be a standard R model. if it sits about 6" above the rails the cab is "raised". Early Fuel tanks also used the front or rear or both cab mounts as a support so that may come into play? are you converting a R600 to a R700? Trent

Rob next time you see a frameless end dump look at the trailers 5th wheel plate. it will have a pivot mount for the hyd hoist and a pivot for the uder carrage beams. becasue of the 2 pivot joints on the plate and the 5th wheel pivot it would be a scary mess to raise or lower the trailer. So what you do is Block the 5th wheel to prohibit its movment. With it blocked now the trailer plate has a solid surface to let the hoist and beams safely work to "inchworm" the trailer when dumping.. most if not all Frameless and 1/4 frames need to be used with a blocked 5th wheel. I have blocked mine as well and did the fab work myself. I have a place on the side of my frame rails under the fuel tank straps that I put mine when not in use..

You can use R model Exhaust hangers and then fab up the exhaust from pipes found online. I was going the route of dual stacks but went with a single instead. What I did to get dual stacks was this. pipe came up between the frame rails to a "T" then the pipe ran across the top of the fram to each stack. Worked good but I went back to a single.. Trent

post a pic of it here and it may drum up intrest. also truck paper.com has a listing for old macks. they dont draw in alot right now with the economy in the tank. i bought both of mine for $500 not runing and $2000 running. I see alot listed for 1-2K depending on condition... rust is the biggest issue with the steel cabs

cement trucks and military

As far as looking at the outside its hard to tell if it has a v8 or not the early R600 models had an option for V8s then in the late 60s I think they only came in the R700 or RS/RL700 models. If the truck had a V8 fromthe factory it would have had a V8 emblem on the hood. on thing to look for is if it has a single stack. alot of the bigger V8s used a 5" exhaust where the Inline 6 had a 4".if it had twin stacks it will be harder to tell as you can run 5" from the turbo to the T pipe under the cab and 4" from the T-pipe to the mufflers. The Stock E9 V8 macks were pretty quiet even without mifflers. I have driven a 440 and 500. the ones I drove spun to 1900RPM and pulled pretty good. you could keep up with new trucks of the same HP all day. the company I drive for had a 2002 pete with a 550 cat and the 440 mack would walk on it up to about 60MPH.

You need to find the torque rating for the 5 speed spicer.If its as old as the 673 it will likely not have the raing that the maxidyne can put out. It is a rule that the older 2 countershaft Mack transmissions are stressed with the maxidyne high torqe engines. If its a toy it wont be a big issue. if its going to do some offroading the old trans will not like it with all that gear reduction and high torque. the older 5 and 6 speeds are direct drive the newer 5-6-7-8-9 speeds are overdrive(a very fast OD) so fast that you would likely need to put slower rears in to slow the truck down. If you looking for a good on/offroad for a old military truck here are the options I would do. 237-285-300 Maxidyne>6 speed> 4.17 (or slower rears) good for about 62MPH 300 Maxidyne>7 Speed> 5.73 rears (or slower rears)good for about 62MPH 350 Econodyne> 8LL > 4.17 rears (or slower rears)good for about 70MPH Im sure others could add some options.

The thermodyne was a Diesel commonly used in the 50s. I dont recall what year production started but it could have been in the mid 40s. It was a engine model term used to discribe the engine series. they commonly came in 673,711 CID some turbocharged some Natural asperated. They needed to be kept in the high RPMS to pull good. The Maxidyne was the engine that came out in 66-67? High torqrise. In its day it was a power house and a blessing. you went from around 180HP,600TQ to 237HP/900TQ and only needed 5 gears to pull the same load a thermodyne with an 18 speed needed. Maxidynes came out shortly after the R models were released. the first Rs had Thermodynes. Some have recently said the last few B models had Maxidyne test engines in them? Econodyne was another version basicly a copy of the maxidyne but needed a few more gears to get the job done. they had a little more HP but had a little less overall TQ HTH Trent

max RPM with no engine load was 2300 Max RPM with load was 2100 you can spin them to 2300 But I think most will agree its better to keep it at a max of 2100.

Volvo ownes Mack and they have been playing games both with building new trucks and parts for older trucks. Alot of old R model parts are being made in inda or simply outsourced to cheeper companys. You can still get all the engine parts but they will be a day when it starts to get a little more difficult. Volvo wants to move forward with their buisness plans and really does not want to keep the solid R models onthe road . How bad will it look when a 30 year old truck is still running better then their new stuff??.Right now some of the interior parts are NLA or "out of stock" luckly there is an aftermarket company called PAI that makes alot of mack parts. Trent

I think david is right the superliner II had the same frame as a MH. I stand corrected.. Other dog regardng the hood length and engine. the superliners I drove had the dual air cleaners,twin stacks and bug shelds on the hood. I could hide a full size cadillac over the hood at every stop light. could barely see when backing a short 22-24' dump trailer. first I would louse it in the mirrors then couldent look out past the stack if the trailer waskinked a few feet out of range of the mirrors..unless I was jackknifing it and at that point I could not recover.now try and back around a cul de sac with park cars on both sides...you had to be the one shot king with that truck!... I like the300-350 macks for pulling the low RPM range but the 550 cats will easy out pull them. Maintance wise the Mack will be cheaper in the long run unless volvo Fcuks that up

the RW should have a diffrent frame than the R688. superliners shared a frame with the MH. both will be great trucks. The superliner is considered a "classic" long hood model. If you want something a litte diffrent than go with the RW,however if your working the truck the RW is not the best for tight city spots as that hood hides cars and fire hydrants easy. not as bad as a long hood pete 379 but you get the point. the 4 valve engines will have better part availibility but volvo will screw that up soon. Both engines are great runners just dont expect a 20 year old engine to out perform a new cat 550. Cabs are the same inside. the RW will have more ease to work on as the cab sits higher off the frame and the engine to fire wall clearance is about 12" vs the 2" found on the R688. Again both are strong trucks and you cant go wrong with either model Trent

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LOL I thought he was talking Ontario Ca USA!!! thats just 5 mins from Fontana Ca USA sorry for the confusion. your 2600 miles from that yard !!!

as the guys mentioned those air cyl get gunk in them or the oil thickness can cause issues when cold. A worn orings let oil in and then the cold weather slows the piston movement if dirt got in with the oil. if it has an exhaust screen clean that out also. that would be my first things to look at.

there is a scrap yard in Fontana.. cant recall the name tho... just saw someone post about it I think over at ATHS site???

ye he said it was a wester star. only got his but wet, said had time to get out then get back in to radio the convoy he was of his problem then get back out LOL. shallow water 20' deep. hauling wood on the rear and insulation on the front of his trailer.