Extra gearshift on M38A1 jeep

dynodave · Post by **dynodave** » Tue Sep 08, 2009 7:06 pm

I believe my M38A1 has a modified transmission. There is a 4th lever in between the gearshifts and gear selector. I am not sure what it is for or if it was ever used on M38A1's. I think it was a modification since the emergency brake is missing. Can anyone help me and give me some idea what this is for? I would like to return the jeep to stock so not sure if I can trade this in or what my options are. Any help is appreciated.

Picture of the gearshifts:

Picture of the transmission housing:

[/img]

linx310 · Post by **linx310** » Tue Sep 08, 2009 7:09 pm

It could be one of two things:

1. Some type of power take off (PTO), do you have a wench installed?
2. An overdrive.

I am betting its an overdrive.

dynodave · Post by **dynodave** » Tue Sep 08, 2009 7:16 pm

NO PTO is installed...thats what I thought it was when I first saw the jeep. After reading your post and searching, it does appear to be a WARN Overdrive. Now the decision is do I keep the Overdrive or return it to stock?

cody10414 · Post by **cody10414** » Tue Sep 08, 2009 8:42 pm

I have one of those Warn ODs on my M38A1 and would never dream of removing it. I drove without one for the longest time, and cant bear the thought of going without. Those puppies are getting rarer and seem to recall them going for about $1000.00 take-out.

dynodave · Post by **dynodave** » Tue Sep 08, 2009 8:57 pm

cody10414 wrote:I have one of those Warn ODs on my M38A1 and would never dream of removing it.

How did you finish it out in the cab? Do you have a picture? What did you do about the parking brake? Just curious.

MODIFIED · Post by **MODIFIED** » Tue Sep 08, 2009 8:58 pm

Dave, depends on you intended use of the vehicle. I know you mentioned "stock", but to what degree. and do you wish enjoy the vehicle during the process of your restoration?

If you intend, to make use of the vehicle, either frequently with marginal highway use and/or otherwise light offroad and the like,. keep the OD!!!,

couple links:

http://www.vernco.com/od/

http://www.hermtheoverdriveguy.com/id20.htm

Benifits:

the Warn overdrive acts as a gear splitter in all gears; both in forward and reverse, 2WD and 4WD, and High and Low. Your basically doubling to the existent range of what you inherently possess within your stock config. (ex: 3 speed t-90 turns into 6 speed capability with the OD. )

keeps the rpm's down: top rpm for the stock F134 long rod motor is 3200 sustained. any more than that for long duration is going to make your life complicated.

you'll avg, 25% increase on MPH to RPM. (not on the hills though, will not increase your horsepower!)

more mph to rpm= better mpg on highway for sure

should you choose to sell it?:

first,
check the diameter of the intermediate shaft of your trans case.

or,
count the teeth on your bull gear 29 or 26 teeth) and get your output shaft spine count(should be a "6")

I've seen warn units sell for as low as 550.00 on the epay and they all needed rebuilds that would cost another 500.00. I got mine on C/L and it needed a rebuild, Herm @ www.hermtheoverdriveguy.com rebuilt mine for my 1955 M170, I swear that was the best money spent since buying this lassy(considering my intended purpose=driving it). He is hands down the authority on these OD's. I defer you to him for any tech assist.

Good luck, and congrats.
Congrats meaning, you discovered a jewel that would serve you well either is use, trade, or money in your pocket

dynodave · Post by **dynodave** » Wed Sep 09, 2009 8:22 pm

Thanks for all the help! The links are what I was looking for. The main reason for wanting to return it to stock would be to Keep it Simple (KISS!) However after some reading it definitely is something that is worth keeping.

This jeep is definitely a jewel. She started right up after replacing all the wiring. After 10 yrs of sitting in an old barn its in pretty good shape. In one respect I want to strip it down and rebuild it from the ground up but then it is in such good condition I just want to get it running...decisions decisions.

GIJOE290 · Post by **GIJOE290** » Thu Sep 10, 2009 7:21 am

Dave , post more pictures of her.

dynodave · Post by **dynodave** » Thu Sep 10, 2009 5:35 pm

I will have to get a few more on the computer but here is a picture of what she looked like when I found her:

Boomer573 · Post by **Boomer573** » Fri Sep 11, 2009 9:59 am

Could you please send a side view of your jeep. It looks like it has a hard cab installed. I know they are not stock, but one was included in my purchase, and I want to see how one looks installed. Thanks

SteveJ · Post by **SteveJ** » Fri Sep 11, 2009 7:52 pm

It looks like a user to me. You should drive it and restore it slowly. Taking it completely apart sometimes becomes overwhelming and a lot never go back together again. The fun is in driving and enjoying.

SteveJ · Post by **SteveJ** » Fri Sep 11, 2009 7:59 pm

To DynoDave

This overdrive installation does not affect the parking brake. It attaches to the auxillary bay on the trasfer case not the main output shaft.

You also do not need to modify the floor. You can rig to engage and disengage from underneath. You just have to crawl under the jeep to do it. Most of the time you will have it engaged for normal driving anyway.

oilleaker1 · Post by **oilleaker1** » Sat Sep 12, 2009 3:55 pm

Amazing, the previous owner installed two electric winches mounted vertically. What was it used for? Yes, the overdrive is a great asset. You must have good steering and suspension to handle the extra speed however! Fun looking toy! John

dynodave · Post by **dynodave** » Sun Sep 13, 2009 7:05 pm

Sorry all, I was gone for the weekend. I will post some pics of the side hopefully tomorrow.

As for the winches, they are 12V each. The jeep was used for some serious offroading I was told. I have found some red paint and a metal tag that says Ft. Knox KY so I believe it did some time as a fire service vehicle. It is great learning about its history.

The parking brake was removed from this vehicle. Does anyone have a picture of the parking brake setup underneath? I assumed it got in the way because the WARN's housing is close to the drum of the emergency brake. I would like to get it set back up with the emergency brake cause I know how those old brakes can be!

dynodave · Post by **dynodave** » Tue Sep 15, 2009 4:53 pm

The weather isn't cooperating so I haven't been able to take it outside to get more pics. This is the best side shot I have. If you want some closer or better pics let me know.