Farmall1212 Posted November 28, 2019 Share Posted November 28, 2019 Need to swap the old 24 volt starter in a B67 to 12 volts. Someone took the parallel switch so it is either switch alternator to 24 volt or starter to 12. I know it is done, does anyone have a starter model number that the old one crosses to? Old starter number is a Delco 1113700. By my research it crosses to a MT40. Will it drop in or do I need a specific MT40? I am only wanting to be able to crank the engine and have headlights as far as my electrical system goes, it is a site truck In The mountains so I don’t need anything else, I am eliminating everything else. Thanks for any help. Quote Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/ Share on other sites More sharing options...
Rob Posted November 28, 2019 Share Posted November 28, 2019 (edited) 39MT, 40MT, or 42MT clockwise rotation, 11 tooth starter drive pinion is the starter series you'll require for that conversion. Edited November 28, 2019 by Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436839 Share on other sites More sharing options...
Farmall1212 Posted November 28, 2019 Author Share Posted November 28, 2019 What are the differences in each model and should I look for one over another? thanks for the info. Quote Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436848 Share on other sites More sharing options...
Rob Posted November 29, 2019 Share Posted November 29, 2019 39MT is a newer permanent magnet gear reduction type starter. It is quite a bit lighter than the much older 40MT, and somewhat newer 42MT. Both of the older units are very heavy and any of the three will serve your purpose. I have three 40MT series with the heavy duty eight brush commutators and they are trouble free. 1 Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436863 Share on other sites More sharing options...
Freightrain Posted November 29, 2019 Share Posted November 29, 2019 I put a 40MT in my truck nearly 20 years ago. I swapped it for an air starter a couple years ago(just because I like being different). That 40 MT is very, very heavy. The air starter is a feather compared to it. You don't really have to change any wiring, other then adding a starter solenoid(like a Ford) to fire it. I removed my S/P switch and mounted the solenoid in its place, that way I could use the wire from the starter button on the dash. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436867 Share on other sites More sharing options...
Rob Posted November 30, 2019 Share Posted November 30, 2019 I'm going to try a 39MT on my B-61ST which is still 24V start. I have several s/p switches around the shop and really don't have a lot of problems, but it's nice to simplify in wiring along the way when modernizing. The 82 E6-350 in my B-61 has a "Prestolite" starter which is 12V so going to convert that truck first although it always started fine with it's s/p switch which is original from 1957 and rebuilt by me in the early 80's. Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436932 Share on other sites More sharing options...
terry Posted November 30, 2019 Share Posted November 30, 2019 1 hour ago, Rob said: I'm going to try a 39MT on my B-61ST which is still 24V start. I have several s/p switches around the shop and really don't have a lot of problems, but it's nice to simplify in wiring along the way when modernizing. The 82 E6-350 in my B-61 has a "Prestolite" starter which is 12V so going to convert that truck first although it always started fine with it's s/p switch which is original from 1957 and rebuilt by me in the early 80's. The early 24 volt starters with the S/P switch when everything was in good condition would really spin the engines for cold starts. terry Quote Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436938 Share on other sites More sharing options...
Rob Posted November 30, 2019 Share Posted November 30, 2019 That is very correct but they require what I consider "routine maintenance" to have a long lifespan. Most didn't get anything till failure so caught a bad rap, (my opinion). A 12V 40MT, nor 50MT starter on my 1693TA engine does not spin the engine near as well as it's original s/p setup. Only matters in very cold weather and nothing referenced is a working truck any longer I own. Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-436942 Share on other sites More sharing options...
Farmall1212 Posted December 21, 2019 Author Share Posted December 21, 2019 Got a 39 mt starter and it is 12 spline Mitsubishi. Anyone know if the Delco pinion fits the Mitsubishi? Price was right. Quote Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-438509 Share on other sites More sharing options...
Rob Posted December 21, 2019 Share Posted December 21, 2019 2 hours ago, Farmall1212 said: Got a 39 mt starter and it is 12 spline Mitsubishi. Anyone know if the Delco pinion fits the Mitsubishi? Price was right. You are asking if the original 24V Delco starter pinion will fit the Mitsubishi built 39MT series copy? No, it will not. Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-438510 Share on other sites More sharing options...
Farmall1212 Posted January 2, 2020 Author Share Posted January 2, 2020 No what I meant was if the delco pinion from a 39mt would fit the Mitsubishi. I found the correct delco 39mt since this post. Will let you know how it works once I get it installed. thanks Quote Link to comment https://www.bigmacktrucks.com/topic/59990-24-to-12-volt-starter-swap/#findComment-439270 Share on other sites More sharing options...
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