O'Brian dana 18 Gears set??

i've seen a couple of people on this and other websites that say they have an O'Brian 4.0 gear set in their model 18 T-case, who makes this?? where can i get more info?

 

The lowest I've seen here lately is 3.15:1.
I'd love 4.0:1 though.

 

It is Jack Obriens four wheels west in Roseville Califorina (916)773-3278 I dont think he has a website ,the only draw back to the 4.1 gears is you can not run an overdrive unit with them and you have to have mods done to your case to fit them but his gears are great I have the 4.1 set in my 71.He also makes a 4.86 set for the guys that want super low speed.

 

Put a 3:15 kit from TerraLow in Dads SN5. Works really well with the 5.38 gears. Only problem with the 225 is that first is really low, and the low end torque can be pretty high, so its hard to drive real smooth in 1st gear low range. Really a nice problem to have. Also on some obstacles that require a little of momentum, first is sometimes too low, and 2nd too high. Very rare, but a frustrating little problem. Kit went in easily, no grinding, or mods to the case. Just make sure you get the large Intermediate shaft version, or have someone who can open that hole up on the narrow shaft version. Kits are expensive, but give great trail control. Let me know if you have any other ??s.

 

herm has an od bowl gear for BOTH the tera-low and Jack O'brien gear sets.

www.hermtheoverdriveguy.com

 

CJMase, You're right on about gearing with 5.38's, T90 and O'Brian Rock Eater T.C. Honestly, it's a great improvement if you want to hide modifications. Had I known what we now know, I would have installed a Granny 4spd. and saved money.

 

obrian stil makes the 4.86 gears for the dana 18?
and how can i come in contact with him.

i dont want to wheel with a crawl ratio of 28mehh
and with this i come down to 54

gerald

 

I don’t think so. I tried contacting them a couple of years ago and came up empty.
The only company I know of still making low range gear sets for a Dana 18 transfer case is TeraFlex.

 

O'Brian is open and still makes the low gears and the phone number is good.

 

http://www.extremegearoffroad.com/teraflex.htm

 

4.86
[

 

Very interesting pics.
Seems strange that the front output threads are the early type and the rear output threads are the later type.

 

No big deal. When a part needs replaced frequently you use what parts are available. No real strength difference between the two as other than the threads, nut, and washer, they are the same.

 

Holy *&^@ look at the size of those gears! I wonder if there's any strength issues with the drive gear being that small??