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M38 Engine Serial Number Question
Posted: Wed Feb 18, 2015 2:31 pm
by ojgrsoi
I am working with a customer to try to identify the year of his M38. There are no dash data plates and no plate behind the passenger seat. The engine number is 4T38605. I was reading where the engine serial number for the M38 begins with MC and may have an R in it. The engine may have been swapped in.
Do Canadian M38's have engine serial numbers that start with MC?
Are there any other attributes that would distinguish years for the unit?
Any assistance would be appreciated.
Thanks.
Posted: Wed Feb 18, 2015 3:43 pm
by AAHUNT
From what I understand (and I'm not an expert by any means) is that Canadian Army jeeps often have the serial number stamped on the top left front frame rail. If its a M38CDN, then the frame # should be something like 52-3XXXX
Posted: Wed Feb 18, 2015 4:08 pm
by aforests
The serial number off your engine is a Willys pickup serial number, so not original to the jeep.
Posted: Wed Feb 18, 2015 5:56 pm
by 4x4M38
There are other clues to dating an M38 besides the serial number.
Changes in production occurred during its delivery span.
Folks here can't give you a specific date without a serial number,
but things like whether the gauge panel had a circuit breaker
mounted on it, whether a primer pump is installed, radio power
bracket, accessory plug were installed, early of late firewall, etc.
Give us done clues and maybe we can narrow the window.
Thanks!
Posted: Wed Feb 18, 2015 6:46 pm
by ojgrsoi
Thanks. I will get with the owner and see what we can see.
Posted: Wed Feb 18, 2015 9:49 pm
by wesk
Fill out our survey form on that friend's M38 and send it to me.
http://www.willysmjeeps.com/v2/modules. ... tit&lid=76
Posted: Thu Feb 19, 2015 7:26 pm
by ojgrsoi
Posted: Thu Feb 19, 2015 7:32 pm
by ojgrsoi
It was pretty amazing that on the survey provided that I could answer none of the questions based on the removal and modifications on the M38. One item I did see was a 43 over a line and 8 under the line on the rear differential. The sarge that owns this rig has done quite a bit to make it roadworthy. While far from pristine it is kind of a neat rig that was saved from the bone pile.
We will be able to title because there is a serial number on the block. Hope to hear some comments on a year based on the photos.
I appreciate your help.
Mark
Posted: Thu Feb 19, 2015 10:27 pm
by wesk
The tub is M38, the majority of the remaining parts are civilian jeep. The chassis is civilian jeep as well. I'd guess someone had a very well rusted out CJ2A or CJ3A and found a decent M38 tub for it and a truck engine that was running.
Posted: Fri Feb 20, 2015 4:04 am
by ojgrsoi
Thanks Wes. What distinguishes the chassis? And is there anything that distinguishes the year model of the body?
Again I appreciate the help.
Mark
Posted: Fri Feb 20, 2015 9:27 am
by wesk
The M38 frame front rails are boxed from the bumper to the firewall and the M38 does not have that grill mount bracket.
The survey needs to be completed in detail and returned for me to offer an estimated DOD on the tub. There is no need to run the survey against the mostly CJ2A parts. Just against the tub and accessories attached to it.
There is a survey photo guide in my photo album which was also listed on the survey form:
http://www.willysmjeeps.com/v2/modules. ... php&page=2
Here in Wisconsin that jeep could only be titled and registered as a owner built vehicle from spare parts and Wisconsin would assign a serial and stamp it on the jeep.
You can usually narrow down the tub DOD to within 6 months but you are missing a lot of the parts that help with that ID. The frame, front sheet metal and running gear are all CJ2A. The engine is Willys truck. Essentially 75% of the jeep is CJ2A and in most states he would be forced to register as a CJ2A or a home built jeep from parts.

Here's an example of a complete dash.

This is a latching type M38 tool box.

Early M38 Firewall

Late M38 Firewall
Posted: Fri Feb 20, 2015 10:53 am
by ojgrsoi
I appreciate your assistance. In TX it will be titled as a Willys CJ3A and carry a reconstructed brand on the title because of the body change. The serial number from the engine is used for the VIN in most vehicles 1955 and older except Ford.
Sorry for missing the link to the gallery.
I am sorry to say that there is nothing on the survey to complete because of the dash being gone and replaced with a flat plate and gauges. None of the electrical is original. The intervehicular cable socket is on the LR fender. What I see from the firewall photos above would lead me to believe it is a late body.
Again thanks for your assistance and let me know if there is anything I can do for you.
Mark
Posted: Fri Feb 20, 2015 12:30 pm
by wesk
Late firewall would be about Apr/May 52 and on.
That frame was used on all the CJ2A's from 1945 through 1949 except a few very early 45's that had the steering bellcrank still on the front axle housing. It was only used at the very beginning on CJ3A production in 1949. Here's a good link to sort out CJ3A info and ascertain if it is really a CJ3A.
http://www.cj3apage.com/index/Tech_Tips.htm
If it turns out it is not a CJ3A running gear check the CJ2A page at:
http://www.thecj2apage.com/
Posted: Wed Nov 23, 2016 7:36 am
by 4x4M38
Hi Mark,
Hard to really tell but it looks like the floor is in decent shape. No holes.
It also looks like the body is pretty good, but you won't know for sure without
getting through the paint and filler. Also check your hat channels under the tub.
Being in SE Texas rust is usually a major problem. Note the brushed on paint
inside the rear of the tub. In my case Bubba glued down carpet everywhere after he brushed on layers of heavy paint. The carpet is gone but the glue remained.
You still have a lot of stuff that people spend time looking for. Be grateful for that, and it runs!
Congrats