Starter motor on ENDT-676

[Cedarola]

Hello everyone, been reading and learning from these forums for a bit, so thanks for that. Now I’m trying to find something I thought would be simple and I can’t… I have a ‘79 RS685LS, not sure why it’s not R686, or what the LS stands for, but that’s what the tag says. I need to know what starter it has so I can order one without having to pull the one it’s got out first… we’re currently using the truck to site-mix and pour a remote job, and right now the starter works, but I don’t want to be left hanging once it goes. Been starting it by tapping the starter lightly, but it’s getting worse. I can see that it’s 12v and CW rotation, but that’s it. From my research I come up with one that might work, Delco Remy 39MT or equivalent… but not sure… anyone know? Or reassure me that I can just keep tapping it for another dozen starts? 

[fjh]

15 hours ago, Cedarola said:

Hello everyone, been reading and learning from these forums for a bit, so thanks for that. Now I’m trying to find something I thought would be simple and I can’t… I have a ‘79 RS685LS, not sure why it’s not R686, or what the LS stands for, but that’s what the tag says. I need to know what starter it has so I can order one without having to pull the one it’s got out first… we’re currently using the truck to site-mix and pour a remote job, and right now the starter works, but I don’t want to be left hanging once it goes. Been starting it by tapping the starter lightly, but it’s getting worse. I can see that it’s 12v and CW rotation, but that’s it. From my research I come up with one that might work, Delco Remy 39MT or equivalent… but not sure… anyone know? Or reassure me that I can just keep tapping it for another dozen starts? 

39mt should be correct   LS   Light Steel Frame  I believe!  If it had RL 685 it would be an aluminum frame! 685 Is it single drive  axle? Where is Kevin when you need him !  (kscarbel2 ) he's a walking  Mack encyclopedia !

[doubleclutchinweasel]

"RS" prefix should be a Western version of the "R" with a steel frame.  "RL" prefix would have been a Western "R" with an aluminum frame.  "L" suffix is for lightweight components (check for an aluminum bell housing, for instance).  "S" suffix is tandem drive.

R685 and R686 would have different engines.  Not sure what the HP ratings would be for 1979, but originally (like in 1967) the R685 was the ENDT-675 237HP Maxidyne.  R686 was a larger engine (ENDT-676 285-300 maybe?).  And, again, the Western versions may have been different on engine specs...I don't know for sure.  Most of my knowledge on these things stops in about 1973!

 

Edited August 18, 2023 by doubleclutchinweasel

[doubleclutchinweasel]

Oh, and sometimes cabs and hoods get swapped.  The VIN number on the frame might tell a different story.  Might really be a 686, for instance.

Edited August 18, 2023 by doubleclutchinweasel

[doubleclutchinweasel]

I can't make out all the words, but the stuff in the red oval is all aluminum on the "L" suffix trucks.

 

[Full Floater]

39MT.   I have and have had several in service.....they've been pretty reliable.  And way easier/lighter to fandangle into place

[Geoff Weeks]

Near as I can determine, it should take the very common starter that Mack and Cummins used. So a replacement Delco 39 for a Cummins six should bolt right in, may have to re-clock the nose.  That is if the shop can't look up by the Mack spec's for some reason.