"Overdrive"

52 wagon

Gear Grinder
Aug 24, 2010
20
Texas
Willys Model
Willys Year:
Well Herm did me right. It wasn't the cheapest upgrade but for a daily driver it was needed the most. A 26 tooth Warn Overdrive from Herm the Overdrive Guy. If have the means I highly suggest picking one up.
 

mikec4193

Precision Fit
Jan 18, 2010
864
Mechanicville ny
First Name
Mike
Willys Model
  1. Other
Willys Year:
  1. Other
Hi Billy 52 Wagon

So how long did the swap take??...what kind of numbers as far as MPG goes did you gain??..more top end speed too???. I would love to add one to my truck. I have been told these trucks are dog slow and they cant go by a gas station too well either. I have heard 45mph is about top end for these Willys vehicles and about 10mpg.
Thanks for any insight.
Mikec
 

52 wagon

Gear Grinder
Aug 24, 2010
20
Texas
Willys Model
Willys Year:
mikec4193 said:
Hi Billy 52 Wagon

So how long did the swap take??...what kind of numbers as far as MPG goes did you gain??..more top end speed too???. I would love to add one to my truck. I have been told these trucks are dog slow and they cant go by a gas station too well either. I have heard 45mph is about top end for these Willys vehicles and about 10mpg.
Thanks for any insight.
Mikec


Mike
It took me an hour the snap ring is a pain and I had a 2 year old for a helper. I do not know my mpg yet but with the lower RPMs I can Imagine it will improve. Its not cheap but my wagon is my daily driver 60miles a day round trip so it was a necessity. Good luck to you and let me know if you have any questions.
 

dirtbuggy

Precision Fit
Sep 29, 2010
574
new river az
Willys Model
Willys Year:
10/4 I got one from herm last year for my 2a havent driven it much on the big road still waiting to fix the tub but he is a great guy and a good person to talk to wish I could afford to put one on my 62 pu its my daily driver but I dont go too far anyway might have to take the one off the flatfender (47cj2a) and put it on the old pick em up will see.
 

BradW

Bigger Hammer
Oct 11, 2009
64
Wenatchee, Washington
Willys Model
Willys Year:
I totally agree with having an overdrive unless you just plan to drive around town, My 59 (wagon) is a daily driver and even with a good running 226 it's top speed was around 55 and it was screaming, I picked up a used overdrive on EBay and it makes quite a difference, I can do 70 now if I wanted but the engine will run out of power on hills before I run out of gears. I drive 15 minutes to work on a highway where the speed limit is 60 and most cars are going 60-65, it's nice to be able to go with the flow. The hard part of the installation for me was mounting the shift lever to the transmission housing (not really that hard) the gearing in the transfer case was fairly easy. I've heard good things for a few years about Herm the overdrive guy and would use him if I had to do it over again.
 

dirtbuggy

Precision Fit
Sep 29, 2010
574
new river az
Willys Model
Willys Year:
go to vernco.com and look around in there he will direct ya to another website I forgot the name who has a really good writeup on the over drive good luck
 

alphlulu

Bigger Hammer
May 13, 2010
122
San Jose, CA
First Name
Ron
Willys Model
  1. Pickup
Willys Year:
I also purchased an overdrive from Herm about 3 months back. It was fairly simple to install, the snap ring is a complete pita. It took me about 3 hours, slow, steady, coffee breaks etc. The snap ring was 45 minutes.

But it was worth it, quality of Herms stuff is excellent, directions good, and it makes a heck of a difference.
 

48wagonguy

Sharpest Tool
Jul 30, 2011
262
Port Orange, FL
First Name
Bruce
Willys Model
  1. Wagon
Willys Year:
  1. 1949
This is really good to hear. I've been planning on one of Herm's overdrives from the start of my build. It's on hold now, but I will definitely get with Herm. Thanks for the heads-up on the snap ring - at least I won't think it's just me, now!
 

AustinJpGuy

Sharpest Tool
Oct 12, 2012
395
Potomac, MD
First Name
Austin
Willys Model
  1. Pickup
Willys Year:
  1. 1955
So, who exactly is making these things now?

Advance adaptors is selling the saturn, based off of original Warn.

-Herm is selling the ATV one a little cheaper at $840 for standard applications. How does it differ from the saturn/warn?

Anyone selling rebuilt versions? Need one, and was going to ask for one for christmas. Want to be able to drive my willys to and from school eventually.
 

Ray Gun 19

Sharpest Tool
Nov 25, 2012
205
Glen Ellyn, Il
Willys Model
Willys Year:
Have you guys thought about just using a an AX15 transmission? Or NV3550? 5 forward gears that are all synchronized seems a bit better than 2 synchronized and an OD. Just curious.
 

AustinJpGuy

Sharpest Tool
Oct 12, 2012
395
Potomac, MD
First Name
Austin
Willys Model
  1. Pickup
Willys Year:
  1. 1955
Have you guys thought about just using a an AX15 transmission? Or NV3550? 5 forward gears that are all synchronized seems a bit better than 2 synchronized and an OD. Just curious.

Im sure you would need some big money adaptors to do so with the stock t case and engine. It would make alot of sense to go Jeep Cherokee drivetrain: 4.0L, AX-15, NP231. But for me its original or bust!
 

mathman

Well Oiled
Mar 14, 2012
2,988
AR
First Name
David
Willys Model
  1. Pickup
  2. Forward Control
Willys Year:
  1. 1950
  2. 1964
-Herm is selling the ATV one a little cheaper at $840 for standard applications. How does it differ from the saturn/warn?

Herm sells rebuilt Warn units as well...
 

johnrb3b

No such thing as too many Jeeps
May 19, 2011
1,308
west suburbs of Chicago
First Name
John
Willys Model
  1. Wagon
Willys Year:
  1. 1957
Herm is selling the ATV one a little cheaper at $840 for standard applications. How does it differ from the saturn/warn?
Herm's is also a copy of the original Warn / Saturn. He's made some little changes to beef up the gear carriages.
The biggest difference is in the "tech support" from Herm. He's the greatest. You talk directly to him. If there's any problem he'll make it right.
My 3B is a bit of a Jeep Salad. The engine (and probably transmission) is from a 1953 Truck or Wagon and the match between the tranny and transfer case is off just a little. The overdrive kept popping out of 1:1 under acceleration. Herm figured it out, sent me some shims and it now works perfectly. Go with Herm.
 
Last edited:

johnrb3b

No such thing as too many Jeeps
May 19, 2011
1,308
west suburbs of Chicago
First Name
John
Willys Model
  1. Wagon
Willys Year:
  1. 1957
He will need to know the tooth count on the gear that's visible when you remove the round plate on the rear of the transfer case.
Call him on the phone and actually talk to him. That's the best way to handle it. He's fun to talk with.
 

scramboleer

Super Moderator
Staff member
All-Star
Aug 16, 2011
11,474
San Francisco, California
First Name
Dan
Willys Model
  1. Wagon
Willys Year:
  1. 1964
The main thing is how many teeth the main gear of your D18 transfer case has - 26 teeth or 29 teeth. Give Herm a call. As others have mentioned, he's wonderful to work with.
 
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