Need help with starter problem - update

32sbct · Post by **32sbct** » Wed Jun 24, 2020 7:59 pm

I finished rebuilding my jeep about two years ago and have a little over 200 miles on it. Since day 1 it would occasionally grind when trying to start. Over time it has gotten worse. I should have jumped on it right away but I didn't get to it until today. Here is some info that should help.

The jeep is a 1952 M38 that was modified in it's past by replacing the original motor with a 1942 Willys MB motor. The motor was rebuilt.

Sometime in it's past it was converted from 24 volt to 6 volt and converted to key start. I had the starter professionally rebuilt to 12 volt. The starter has a nine tooth bendix. I have no idea what starter I have, there are no markings on it at all except for a 731 casting number.

The flywheel was inspected and resurfaced. It is the original M38 flywheel with 129 teeth. The transmission is original to the jeep and was rebuilt.

I removed the starter today and tested it. The bendix works perfectly. So now I'm really stumped what to do next. The starter and flywheel are correctly matched, 129 tooth flywheel and 9 tooth bendix so I'm not sure why its grinding or how to correct it. I inspected the flywheel and some areas are damaged. I have attached a few pictures. Any and all suggestions are appreciated.

thanks,

Marty

This is probably the worst section of the flywheel. Is this bad enough to require replacement?

This is the starter. I have no idea who the manufacturer was. It came with jeep.

This is a shot of the bendix. It has a little damage but not much.

4x4M38 · Post by **4x4M38** » Wed Jun 24, 2020 8:48 pm

You said the jeep was converted from 24 volt to 6 volt, then you had the starter wired for 12 volts.

Did I read that right?

jam51m38cdn · Post by **jam51m38cdn** » Thu Jun 25, 2020 6:36 am

Ok lets walk through this. Picture number 1 "this is the worst section of the flywheel", its not all the same damage on the edge of the teeth. I would set up an indicator to see if the flywheel is centered on the crank with the 2 tapered alignment studs. Someone had a spec on this, I think it was you know who, the brains of the outfit. Where is it grinding on the bendix, If the flywheel is within tolerance the I would check the play in the bronze bushing on the end of commutator shaft where the nose is that the bendix rides on.Hope this helps, Jim

Post by **wesk** » Thu Jun 25, 2020 12:06 pm

Hello Marty,

Looks like you have a wee bit of a Hermaphrodite setup.

I'd start with your components and wether they fit and work well together.

From my initial observations of your photos it appears you have a very odd starter . Since you had the starter rebuilt I would suggest you corner the rebuilder and have him explain what make/model that starter is. I would be very critical of the depth the starter nose extends into the bell housing. I would be very critical (read accurately measure here) of the throw of that solenoid/linkage/bendix.

Your bell housing adapter plate appears to be the late M38 plate set up for 1/2" starter mount bolts. What are the starter mount bolt hole diameters?

Your block is clearly an early L134 and should be casting # 638632.

Your bell housing I am not sure of. Can you ID it by part number?

Your flywheel appears to be a 129 tooth. Mounting of that late flywheel to the early WWII crank would necessitate a change in dowel bolts on the crank flange.

In short check the actual ID of your components and their compatibility. Measure precisely the throw of your bendix and it's precise reach distance into your bell housing.

I have made some pictoral comparisons of your equipemt to other known applicable units below.

Larger file size: http://willysmjeeps.com/v2/modules/gall ... posite.jpg

32sbct · Post by **32sbct** » Thu Jun 25, 2020 12:15 pm

4x4M38 wrote:You said the jeep was converted from 24 volt to 6 volt, then you had the starter wired for 12 volts.

Did I read that right?

Yes, that is correct. The jeep was an original M38 with a 24 volt military system. When my brother got it around 1977, a previous owner had taken out all of the 24 volt system components and replaced them with 6 volt items. I took the six volt starter and generator and had them professionally rebuilt for 12 volt.

32sbct · Post by **32sbct** » Thu Jun 25, 2020 12:22 pm

Wes thanks for the detailed information. I will go back and and make a list of the exact components tonight. The odd part of this is back in the late seventies when my brother owned this jeep it ran with the same set up I'm running now. It was all taken apart except the rolling chassis around 1979/1980 and stayed that way until I got it in 2011 after my brother passed away.

Based on all the wear on the flywheel being on the front edge I was thinking that maybe the bendix is not really reaching the flywheel properly.

I'll get the component list up soon.

Thanks,

Marty

Post by **wesk** » Thu Jun 25, 2020 1:07 pm

Original 6 volt starters for the Willys 134 were all small frame open nose starters using 3/8" mount bolts. So this makes your purported 6V starter very odd with it's closed nose.

Your starter does not match any 12 or 6 volt Willys L134 starters I have ever seen.

4x4M38 · Post by **4x4M38** » Thu Jun 25, 2020 5:49 pm

Wes,
Was there ever a 6 volt jeep with fording capability that would have used a different bellhousing?

The closed nose is a characteristic of the later M38 starter that used the sealed bell housing.

I was curious. I have the civvy 12 volter in your photo.

32sbct · Post by **32sbct** » Thu Jun 25, 2020 6:31 pm

Wes, Here are the details.

Motor Willys MB casting # 638632 block dated May 15 1942

The Transmission/transfer case are all original to the Jeep. The transmission has a date of 12-7-51.

The bell housing to engine plate is an M38 late model that had the bolt on reinforcement plate removed.

The bell housing is the late M38 with a drain plug, 6 hole inspection cover plate, and half inch starter bolts 4.5 " apart.

I don't know who rebuilt the starter. I dropped it off to Walck's 4WD Jeep shop and they sent it and the generator out for a rebuild. I'm guessing I'll never know exactly who made the starter.

I'm adding several photos that I hope may help with the measurements.

This photo shows the measurement with the measuring tape hook over the backside of the flywheel. It looks like 1 1/4" from the back of the flywheel to the opening for the starter.

Please let me know your thoughts or if any additional photos will help.

Also, any thoughts on the condition of the flywheel. Is it ok to use as is or do I need a new ring gear?

Thanks,

Marty

32sbct · Post by **32sbct** » Thu Jun 25, 2020 7:29 pm

Wes, in regards to my starter I think I know what it is. I believe that it is a Delco Remy 6 volt starter. The one I was looking at online is model 1107075 that was used on late 40's and early 50's Chevrolets. There was one for sale online that had seven pictures and it matched up exactly with mine.

Post by **wesk** » Fri Jun 26, 2020 2:01 am

You want to measure the Bendix throw limits while extending the Bendix electrically not by using your hand on the linkage. See attached drawing for correct method to trigger solenoid and measure throw. I am assuming your starter switch actually grounds the wire coming to it from the starter.

Post by **wesk** » Fri Jun 26, 2020 2:17 am

It is quite possible you are correct about the starter being a Delco with a 1107075 grouping number. That group of starters found in the TM 9-8627 1954 Delco Remy Electrical Equipment Manual are Group 5 starters which include 1107055.

I did start an album with your Chevy Starter in case we determine this is a reasonable substitute unit.
http://www.willysmjeeps.com/v2/modules. ... php&page=2

32sbct · Post by **32sbct** » Fri Jun 26, 2020 2:43 pm

Wes, I hope I did this test correctly. I first disconnected the connector to the armature. I then hooked the positive and negative cables to the battery posts. At the starter I connected the negative to the stater case and I connected one end of an alligator clip to the positive cable and then connected the other end of the clip to to terminal that you indicated.

When I did nothing happened other than some sparks while making the connection.

However when everything is hooked together and I test the starter the drive extends out all the way. Would that happen if the solenoid was bad?

Marty

Post by **wesk** » Fri Jun 26, 2020 11:17 pm

I do not know how your starter switch is wired. Most of those type starters do not apply +12V to that skinny terminal. They ground that skinny terminal. It would be very helpful qat this point to know and see the start switch and it's wiring and the face of your solenoid.

danrothe2001 · Post by **danrothe2001** » Sat Jun 27, 2020 6:00 am

Try placing the ground on the starter frame and positive on the small stud. You should not have to disconnect the large stud. That is the normal wiring for GM solenoids. Don’t leave it extended for more then about 15 or 20 seconds at a time as it is not a continuous duty solenoid. Monitor temps with your hand.

Dan