5.38 To 4.27 Swap. 64' Cj5 With F134 / 4 Speed

Here's a picture of the original one from my '71:


It's since been converted to twin stick. Not a fan of the single stick. Too far of a reach and you can't do 2wd low range.

 

Boy did I ever

 

YEP. I've also realized that, while their site is easy to navigate and its great they have parts easily findable, It's actually way cheaper to source the parts on amazon or ebay. Seems like they upcharge quite a bit on KW.

I'm on the Herm website now and I'm a bit confused. I don't see options for warn OD's in the "new" section. Would this be something only available as a "rebuilt"?

Als, Is there any reason to stay away from the Saturn? Or is it just a preference?
Here's where I'm looking...
http://hermtheoverdriveguy.com/new-overdrives

 

I have a twin stick in pieces. Not sure how often 2wd low range would be needed. Nice to have the option though it would put a lot of torque bias to the rear.
I like to run trails in 4wd as it puts less wear on the rear tires and the trail. I suppose 2wd low range could be used in some technical situations. If I were to
twin stick mine, I would change the 420's case to one without the bulge and ribs. Then I could use a 1310 front transfer case yoke and require driveshaft changes.
The SM420's bottom 2 bolts come from inside the bell housing. A very far off project at best. At my age, it would need to be some sort of catastrophic failure.

 

Warn is no more. The only complaint I have seen with the Saturn is the aluminium shift fork. All of the warns will be rebuilt units. Advance Adapters has the Saturn units.

 

I don't use 2wd low range often but it's nice when you want to go slowly and turn sharply at the same time.

The reach and more positive shifting is the main reason I went twin stick. So much easier than reaching way up under the dash.

Even with the T-18 you need to do bunch of grinding on the transmission case and the twin stick tower to get it to fit:

 

^^^ What he wrote.

 

Overdrive! I run a Saturn and love it.
Regarding twin stick the Jeep T18 I run required no grinding, I run in 2wd on trail easy sections alot.

 

That looks really clean! I suppose the grinding depends on which T-18 is used or the were some differences in the cast for the twin stick.
I had to fab my own brackets for the single stick and transfer case to adapt to the SM420. From your picture I am not sure that would
even work for me. I also have another warn overdrive in pieces. I don't remember what bowl gear it has.

 

I had a similar setup in my '58 as yours with the overdrive in addition. Even an overpass would thwart the mighty 134 in overdrive at "highway" speeds. Don't know if it is normal but I had a problem down-shifting out of overdrive without slowing to a stop. Over all, the overdrive was a great addition to the jeep.



The overdrive shifter (knob between seats) seems to be further back compared to Fireball's setup.

 

I use 2wd low quite often. having a 3 speed, It's like dropping down to granny. even better is 2wd low reverse when moving trailers or working on a hard surface.
Lots of time putting around in 2wd in fields to not tear up the crops.

My warn overdrive shifter is adjacent to the t-90 tower. No issues shifting up or down at any speed. (Knocks on wood)
No issues

 

Yes, when I fabbed the OD linkage, I lined it up with the T-18 shifter (which is forward of the T-14 shifter location) so it's way forward of the twin stick levers.

 

Advanced Adapters is my choice. Had issues with Herm.

 

EVERYONE has had issues with HtOG but he's the most knowledgeable and he supplies parts to AA.

 

I went with a Saturn overdrive on my F134 with 5.38 axles. Gives you the highway cruise and retains the low gearing for when you need it. It will shift in and out of overdrive at any speed.

Here's a handy speed VS RPM calculator
https://www.public.asu.edu/~grover/willys/speed.html

 

Like real world experience with the same configuration!

 

Add to that any gear, high or low range and there is a neutral position hiding there. That saved my butt once when I got so twisted up with the CJ5 it killed the engine. Clutch wouldn't work and couldn't shift the transfercase. But the Warn OD shifted and released everything. That was when that rig was less than a year old.

 

BTDT without an OD. Required some hard pulling on the shifter. That and driving back to look for clutch linkage pieces on the trail or driving home with no clutch. Memories stuck and went to hydraulic.

 

The single stick was introduced for the 1964 model year CJ5A Tuxedo Park, two years before the V6 introduction. The Tux also got a column shift T90c, with the revised 1st gear ratio and 4.27 axles as standard. The column shift left a nearly open floor to complement the standard 1/3 - 2/3 bench seat.
I had a Warn overdrive on my Tux for a while, but the F134 really wasn’t able to pull 3rd overdrive very well with the 4.27 gears. In straight drive, I could touch on 70 mph, but in overdrive couldn’t quite reach 65, though the rpms were a lot lower.
-Donny

 

Agreed and that’s why Jeep in September of 1964 only approved the overdrive for use with 4.88 or 5.38 final drive ratios. In 1964 when it became “Jeep Approved Special Equipment it was never approved for the 4.27 final drive.
Of course that was all prior to the Dauntless.