mechohaulic

for those interested; just looked up mack rear power divider, number of videos also vendors selling the parts(not to take away from Watt's) but to show pictures and proper names of the parts. 

if the small floor board section is what was being replaced, the treadle valve wouldn't need to be disconnected. just take out the three screws holding pedal to floor section. 

4 main parts to the mack auto lock.  1-cage / attaches to input shaft:2 =  wedges(dogs) having two sets =3 = drive coupler /slides input shaft ==4- cone /attaches to output shaft.  wedges are between drive coupler and cage. flat steel band on outside of cage keeps wedges from falling out. as  input spins faster. the wedges are pushed out going against the cone connecting power to output .  it's a brief version with wrong titles to parts; sorry. 

fuel tank vent clogged creating vacuum / flex line in suction side has internal split line restricting flow? one tank or two? 

4 hours ago, h67st said:

I don't know if anybody on this site has experience with those ancient dogs.

and if WE did. we couldn't remember anyway !!LOL

13 minutes ago, Joseph Cummings said:

Their tuna has really slipped in quality over the years too. 

sadly it's difficult to find ANY product today that hasn't slipped in quality. loading bales of shaving at the farm . even that has gone bad. bales go from 20lbs apiece to 30plus. opened a heavy weight yesterday it was saw dust , not shavings. where's quality control. people have expensive animals /pay high prices for shavings; don't want saw dust. even if it's delivered by a Hino = (saved the topic LOL)

On 6/14/2025 at 7:24 AM, Bullheaded said:

I am surprised Hino did not become more popular. I've said it before, I was a truck show years ago at the Mack booth talking with some dealer people and Mack reps and I overhead them saying they don't know how Hino dealers stay in business because they never sell parts or service because the the trucks are so reliable.

bought brand new in '93 a Hino FA  to replace my '77 F=350 flatbed. after checking American made trucks(ford/chevy etc) which needed 40 acres to turn around ; looked into the foreign cab overs=Hino/UD/Isuzu. Hino cost tad more built much better . had the 4 cyl with exhaust brake, room in cab . installed electric PTO instead of very expensive mechanical one. could turn that truck around in a small circle. would have replaced it with the new style Hino if day came .

80 .000 !!!  didn't know  =non planetary how ??? 

could also be an aeroquipt       clothe/ internal braid inside rubber lining having replaceable ends. leaking from movement -- dry rotted ?

1-flex is there; will be easier to replace with same, 2- the flex braided (? doubt ) or rubber flex ; basically a hyd line  (#8)?  remember treadle having a rubber (hyd) line ; don't recall which position. 3- won't be seen or change originality. 

another auctionzip discovery.     just passing on info :: auctioneer Dennis W Ahern . Bequette      vintage autos

6/15/25 .New Douglas Ill. lots 418=442 interesting. 

amazing pictures ;; THANK YOU, great to know there are people still preserving history.

On 6/10/2025 at 5:23 PM, mowerman said:

hehe single axles with spring ride were horrible with no box,,,but just as bad as everything else back then,,bob

back when men were men ;compare a single axle  spring ride U   to a  B or  H model with same specs ,  times change . 

19 hours ago, 67RModel said:

Can't say that I have ever seen a 700 series U model. Would be nice if there was some more pictures and specs. Probably a pretty scarce truck. Not mine. Just reposting and passing along a Marketplace listing I thought was interesting. It looks slightly different than the 600 series U models I have seen. The front fenders and grille look to be about 4"-6" taller.

1974 mack u700 - Commercial Vehicles - Berwick, Pennsylvania | Facebook Marketplace | Facebook

little bit of fiberglass rework and the hood becomes a DMM 

14 hours ago, 70mackMB said:

Like this one Bob?    .....Hippy

have said it before ; this BMT site teaches an ole man new things all the time. ALL the years of seeing the big R fleet  never realized they were U-700's not standard 600's!!

On 6/1/2025 at 7:53 PM, mechohaulic said:

S would be a 6 wheel truck- count wheels not tires .  4 wheels on rear and 2 on steer. 4+2 == 6. the  T in vin would be single axle. while at Mack Blakeslee prestress ordered a fleet of huge heavy DM's . combo of single axles and tandems; the single axles having frame rails ft higher than most were DM611   ?? - all had quads. now I confused myself and contradicted earlier post , they were very heavy triple framed with 100 ton osculating 5th wheels (which I installed everyone ) having 4 in spacer blocks under 5th wheel plates. all 3/4 hand drilled bolts. they may have been DM611  T's

single axle DM's  would be DM611X. looked at one today at truck show in Bethlehem CT specifically to see model . NOT  DM === T's.

On 6/4/2025 at 8:54 PM, Geoff Weeks said:

Test light will work fine, for seeing if he has power to the output terminals! There should be power there all the time, even with the engine stopped or the key off.

not down playing the usefulness of a test light. when a person attempting to find voltage drop uses a test light how does one know if the lighted test light has 14 0r  12 or even 11 1/2 volts lighting the tester. to see if there is any electrical voltage at all  ;  test light quick and easy. I used test light many times.

22 hours ago, Mackman87 said:

you are correct, one portion of the tank (larger portion is primary tank and smaller portion of tank is secondary. It has a small tank inside rail of frame for air compressor relief valves and governor psi. I do have a couple of nice small tanks off a late model RD that I could use, but back to your question, I’m not sure if it would supply the right amount of volume with out breaking out the calculator to do some un welcomed math.lol. I could pretty easily do the two tank mount and leave primary on drivers side and move secondary (I believe, maybe I have that reversed) to passenger side with a small amount of re routing lines. 

 

It’s a single axle, the picture with the axle under the truck is the way it was when I bought the truck. It’s some kind of home made setup. The trailing bar set up was used with mack hangers. Which isn’t correct as mack hangers need an eyelid spring pack to be correct. The truck had the open hook on both ends of spring. This was causing drive line shift and vibrations and the trialing arm was some kinda home made deal. I’m going back with correct spring and pins and remove trailing arm all together. 

the small tank in frame should be the one coming from the air compressor. it is commonly called the "wet tank" since air from compressor warm creating condensation as it  cools developing water. many wet tanks will have short cable connected to spring loaded drain vale for ease of draining.  being a  "Farm boy " myself ; have seen many "fabricated " ideas done on the farm LOL make do with what you have and throw nothing away . that rotted truck wheel might still fit that hay baler  LOL.

these conditions a test light will give faulty info . a meter  is the only way. from this point of view. 14.3 volts off the alternator yet the terminals look like crap. did anyone physically remove the terminals OFF the alternator and with velcro/ sandpaper CLEAN  terminals AND post ????? ALSO  the ground cable going to block needs to be remove and excellently cleaned from rust/ paint. did anyone take a HD jumper cable from ground terminal on alt to separate location for ground ??? anyone check  chassis grounds ?? 

14 hours ago, Joey Mack said:

Can he use the torpedo tanks from a Freightliner C-120 truck, like a Century or Columbia?

yes; if total volume is correct. But that changing tanks could be more of a hassle. the one large tank the picture shows should be a combo wet/ dry tank, relocating proper lines to two tanks a challenge, another question I ponder is :: don't really know what chassis is being worked on since no full model was given or a full length picture. is this a  R6-- T / R6-- ST?   based on one picture looks to be a rear helper spring set up == single axle. part of description states " when I get my axle back from the  differential guy " = possibly rear end being worked on?  single axle one fuel  tank ? right side open ? is a hyd tank also being mounted ? this ending up as single axle dump or tractor ? usually a 6 in channel iron 90 bend holds a pto pump. hope this topic keeps BMT crew updated with progress. 

I would go with cut the V in brackets as I mentioned earlier, reweld the cut ; if need be plate the  bracket  for more strength.  a technical version   is to  calculate air volume in the one tank (which is actually 2 tanks in one ) then acquire two individual tanks of same or greater volume mass  install in chassis. Don't want to go that route unless absolutely  necessary, yes it's been done. your unit with one large tank has a divider internally .