Walker's work doing's

[Wytruckwrench]

Mack’s are a different breed.
I overhaul a lot of Mack engines. I have found that the blocks always need line bored, the cranks are always bent. The bearings will show signs of weird wear patterns. Short of tearing them down to the block and crank and sending them to a good machine shop to line bore and straighten the crank, I put them together and run. They will last a fair time, they are tough.
Something else is that they have different oil pumps depending on if they have jakes or dynatard. The oil pumps look the same at a glance. Get ahold of a good mack Parts man and make sure you have the right one. Due to the bends in the crank and mis-alignment of the block, you can’t trust plastigauge. Just some things I have learned over the years.

 

[walkerv]

Mack’s are a different breed.
I overhaul a lot of Mack engines. I have found that the blocks always need line bored, the cranks are always bent. The bearings will show signs of weird wear patterns. Short of tearing them down to the block and crank and sending them to a good machine shop to line bore and straighten the crank, I put them together and run. They will last a fair time, they are tough.
Something else is that they have different oil pumps depending on if they have jakes or dynatard. The oil pumps look the same at a glance. Get ahold of a good mack Parts man and make sure you have the right one. Due to the bends in the crank and mis-alignment of the block, you can’t trust plastigauge. Just some things I have learned over the years.

I have the right oil pump i dont trust plastiguage either was just using it to find where the oil was going basicaly. This engine has brakes but it has powerleash set up .it nice becuase you dont have to remove jake housings to adjust valves but they suck to adjust , there not bad it just a little more time consuming then i like

 

[walkerv]

That sounds like an easy one to make if you forget to somehow support the weight of the crank.

I'm thinking there maybe two or three common methods. One could use a couple small hydraulic jacks to lift the crank while doing the gauging. Another way I could see would be to remove caps either side of bearing being measured and stick a couple layers of cardboard between crank and bearing then snug up the caps enough to lift crank.

Or you could roll truck over on it's top and do them!

Dont tempt me there is a 345 sitting on the lowboy .yeah i totally forgot to get the weight off crank. I blame the guy who put this pain in my ass shortblock together i should not be doing what im doing due to negligence.

 

[walkerv]

Let the weight of the shaft give an incorrect reading?

Exactly not only was it incorrect it gave a perfect reading as far as that stuff goes

 

[DMiller]

That brain cell failed to fire in my head, we never got .010/Std cranks back from regrind, rods were .010 then too the mains. Sorry for that fail to engage.

 

[walkerv]

That brain cell failed to fire in my head, we never got .010/Std cranks back from regrind, rods were .010 then too the mains. Sorry for that fail to engage.

Its alright I've never had to deal with a mismatched rebuild someone else did ,i will have bearing monday morning . On the pluss side i now know everything is correct under the front cover idler gear is new or has a new bushhing in it all pluggs are in , so that is a positive . At least now i know why oil pressure didnt improve after rod bearings change , it was all dumping out the mains, at least the top end was getting oil still .

 

[kshansen]

Many years ago at one of our sister quarries they had an almost new Mack ten wheeler dumper that they wanted me to check out as they felt it had a rod knock in it. Not sure why but I had a spare set of engine bearings on the shelf so I grabbed the box and drove over to the other quarry.

Listened to it run and it sure sounded like a bad rod, not real bad but for a low hour engine just not right. They asked me to drop the pan and take a look. To my surprise after dropping the pan while looking at the rods found that one rod bolt was not even finger tight! Removed the cap and crank looked good. Bearing was not bad looking but I just happened to have the correct new ones in my truck. Slipped in the new bearing and torqued rod bolts, all seemed good.

Started truck up after putting pan back on and sounded great. Can only guess someone missed that one bolt at the factory and it just took a good bit of running to back out.

Company tried to get Mack to pay for my labor and the new bearing. They said "No problem, but if anything else goes wrong with the engine in the future it's on us!" My boss said "Never mind, we never touched that engine!" Never had another problem with that engine as far as I knew.

 

[kshansen]

Well one good thing is the guy who screwed this one up on you is not there any more, just hope anything else he touched is not waiting to bite you down the road!

 

[walkerv]

Well one good thing is the guy who screwed this one up on you is not there any more, just hope anything else he touched is not waiting to bite you down the road!

Yeah i think that guy was only here a little over a year he spent most of his time in the field ,not on trucks i was hired to be the primary truck mechanic , i will never work myself out of a job here.

 

[walkerv]

Still waiting on my oversize mains that i was supposed to get monday afternoon, did confirm they will be delivered in the am. Next semi quick project is this fine 1983 r686st that decided to break the band clamp off the compressor housing ,its starting to pass some oil so have a turbo sitting on the bench along with a bunch of air intake and charge air hoses that are either cobbled up damaged or is radiator hose.this old girl earns her keep usually hauling liquid nitrogen to the farm tanks or out to the fields. Conveniently it broke down just as she was getting close to the grading shop guess she wants some love too.

 

[DMiller]

R686 was a Good model for Bulldog, long lived and well designed for what it accomplished. A spin off upgrade of the old Bs with a smallish cab, minimal appointments and very stark stoic yet efficient interiors. Heaters left a little to be desired, AC was not much good on the early ones and the cabs would crack from corner across to opposite corner until the later air rides that beat the cowl on the hood edge. Still effective Mutts. That one have the Air to Air Intercooler with Tip Turbine fan? Those were a chunk to get in the way of everything.

 

[walkerv]

R686 was a Good model for Bulldog, long lived and well designed for what it accomplished. A spin off upgrade of the old Bs with a smallish cab, minimal appointments and very stark stoic yet efficient interiors. Heaters left a little to be desired, AC was not much good on the early ones and the cabs would crack from corner across to opposite corner until the later air rides that beat the cowl on the hood edge. Still effective Mutts. That one have the Air to Air Intercooler with Tip Turbine fan? Those were a chunk to get in the way of everything.

Nope this one has a normal air to air, i can't read the reman data plate on engine i know its an e6 , hood is badged with econodyne .

 

[walkerv]

Finally, time to do one steer wheel seal and let it hit the road, gonna have it be my loaner truck as long as they will let me .guage itself it slightly off its reading 30 psi on my eaton scanner.

 

[DMiller]

Finally!!!!

 

[walkerv]

Finally!!!!

Yes sir and thanks to your tid bit of info on when they grind cranks they do all the journals , I will lock that away in the memory bank for safe keeping. Also i had heard a little noise coming from the gear train before that now is gone also. Now i can get to that old mack that needs the turbo and some air intake piping love.

 

[walkerv]

Finally!!!!

Got her parked in the line today i have a driver that will get her broke in and not tear up nothing for a few day pluss he will let me know what isnt rite besides the reverse alarm and city horn and air horn, who knows what else after sitting three years , air system and valves should be ok i spent a week or 2 just fixxing that stuff.

 

[DMiller]

Be ready for all hell to fail!!

 

[walkerv]

Be ready for all hell to fail!!

2 days down all good, from the sounds of it i may have to pick out a new spare truck this driver is liking it

 

[walkerv]

Next project not exactly what i had planned , one head bolt broke rite at its head been like that for a little while but started leaking coolant externally from it .

 

[DMiller]

Work is work!!