Early or Late

[Naugha]

After much research, I purposely switched mine from an early to late setup with a 129 tooth flywheel, mainly to avoid all those issues, but also because parts availability and cost appear to be somewhat better for the late stuff.

I was really going to shut my big yap on this early/late stuff but .....

*Today my local starter shop said he doesn’t usually work on early military electrical components because they have no good source for parts.

*They tested my early M38 starter and said it ‘runs OK’ but I should get the flywheel gear thingy replaced (bendix/pinion assembly) ....... you can get this part for the late M38 starter ..... but I found nothing for the MBP4201UT.

*I also ran across a thread that identified the early starter as having multiple design flaws which is why it was replaced.

I use Google to search within the millitarymjeeps.com site which is the best on line resource for the M38. The amount of info there, however, can become a forrest in which I frequently become lost ....or think I have found everything on a topic .... then another thread pops up which escaped my attention and has all the answers to my questions.... which is a good thing.

*I saw your response and it ‘got me going again’.I have a late engine, flywheel & bell housing plus other early parts and could maybe do some swapping/cash for the later starter, maybe better with more available parts

Thanks for the info.

I will think more on these choices.

[Naugha]

I dropped a short stack of Benjamins on a rebuilt late Auto-lite 24v starter.

Here are a few things I think I saw along the way to my decision:

* Both early & late M38 used starters (cores) can for now be found on ebay.
* I saw more late starter parts available for a rebuild than early model parts.
* I could not find a bendix / pinion gear for the early starter.
* Some of the M38 starters offered on line had a new looking Prestolite ID plate rather than the Auto-lite version that I wanted.

I called three suppliers that offered rebuilt M38 starters. One did not have any M38 starters in stock and said he had problems finding a shop/technician to rebuild cores. Another had only one rebuilt late starter and said he had problems finding early cores without cracks in the bolt mounting area. The third wanted another Benjamin or two for either starter.

I may keep my early starter. According to a shop test it runs but could use a new bendix (rare part/unavailable), which is probably true of many M38 starters. It would only be worth $100 as an exchange core in this purchase.

The engine is back, which will be discussed in another thread...........

[Naugha]

Update.
Here is the 'late' starter I will use.

[wesk]

You are aware that the early starter is used with a 124 tooth flywheel and the late starter is used with a 129 tooth flywheel???? Also the early starter is the small frame starter with no enclosed bendix gear and mounts in a smaller bell housing opening with 3/8" diameter bolts. The later starter is known as the large frame starter and has an enclosed nose over the bendix drive gear and uses a bell housing with a larger opening for it and mounts with two 1/2" diameter bolts.

In short if your old early starter was being used with the correct matching flywheel and bell housing then you will need to replace them with the correct parts for the later starter you just bought.

[Naugha]

Wes, I am using the combination shown at the bottom of your last pic.
Late Starter/ 129 tooth FW / plate with the reinforcement bar.

I decided not to use the early starter that came with the jeep because I think parts are much more available for the late starter. The early starter (which I still have) could use a new bendix gear but that part is hard to find.

My stash of M38 parts has all the various bell housings, flywheels, and plates so I bought the late starter and used the proper flywheel and plate.

I also found a tested VBC-4002UT VR which hopefully will solve that problem and will continue a rebuild attempt on the VBC-40004UT.

The M38 24v generator that came with the jeep is the last major electrical component reliability issue that I need to address before jumping into the wiring harness.

I can sort of see the build process sequence but stuff is in slow motion.

[4x4M38]

Here’s a great start Don, unless you already have plenty of wire and connectors:

https://www.ebay.com/itm/151770768066

[wesk]

The M38 24v generator that came with the jeep is the last major electrical component reliability issue that I need to address before jumping into the wiring harness.

The first and easiest quick test of that generator is to run it like a standard DC electric motor. Connect a pair of jumper cables to a 24V battery source. Then simply connect the red jumper cable to the armature input of the generator then brace the generator so it cannot roll over on you and attach the negative, black, cable to the generator's case. If she spins smoothly, quickly and quietly she's most likely ready to go. Armature is served by 2 wires attached to Pins A & C. Do not use pin B which is the field input.



The ebay link above is a very good source for a harness. The newly built M38/M38A1 harnesses on the market today start at $800. I have used deuce and a half harnesses the last 20 years and they are easily adapted to our jeeps. Over the last 5 years I have purchased several M35 NOS harnesses for less than $100. So just shop carefully.

[Naugha]

Hooked it up to two 12V batteries in series = 25.66V
A burst of sparks then it spun like a top.

[RICKG]

Small victories win the war!

[wesk]

Both A & C would have spread the load application much better.

[Naugha]

Both A & C would have spread the load application much better. / Wes

So. Two pins. One in A. / One in C.
The pins connected by a wire which is connected to the positive cable. ??

Today I am going to spread out my cables on the garage floor and take stock of what I have on hand...... the old harness and the NOS stuff I bought last year. Then I will print out the various diagrams and threads available here on building a M38 harness, which will include decisions about which harness to make and any modifications to the lights. I bought a crimping tool last year but have not yet bought any Douglas components except the stuff already on my wires.

Baby steps..... must take baby steps.

[4x4M38]

Hello Don,
Being 24 volt your lighting mod decisions go one of two ways.

No turn signals.

Turn signals.

Start with that decision. Once made, there are specific things you follow.
Lots of documentation for either choice, and availability of necessary parts.

But decide that first.

Take care,
Brian

[RonD2]

Just a thought......because the M38 originally didn't come from the factory with turn signals, would it be correct to build a new harness without them? And then add them --- the same way the Army would've added them?
I didn't look at the MWO/TB for turn signals --- did it require the original harness be opened up (un-taped) to add turn signal wiring --- or did they just tape turn signal wires over the top alongside the original wiring? Bet the latter. Might even consider not adding the turn signal wiring until after the original harness is fitted to the jeep (same as done in the motorpool). Small points for originality?

Might be a good place to start a new thread about wiring harness?

[Naugha]

Might be a good place to start a new thread about wiring harness?. /. RonD

Yup. Will do.

I have read many threads here on War Jeep lights.
At first I thought... Just use hand signals but later saw that as a bad idea.

Right now, assuming I can build a harness, a version of the ‘Bretto Mod’ sounds cool.

* Front marker lights become Front Turn Signals
* Rear stop/BO/marker lights function as original.

* Something like a pair of thin , detachable Gamma Goat diameter lights added above rear lights.... or something

[RonD2]

It's early, but I'm kind of shocked on your turn signals
I would've bet you'd install them by the book using the MWO.