• Want to add an app icon for this forum to your mobile device's home screen? Check out this thread to see how.
  • Have an event you want to share? Check out the new forum event calendar and how-to use it in this thread here.
  • To both new members and existing members, please read this thread about posting your topics in the correct sub-forum. It makes my job (and my life) a lot easier!

Dana 300: anybody do it?

Quigley

TJ Enthusiast
Oct 20, 2018
153
Kingston, WA

SteveBarrus

Member
Supporting Member
Jan 14, 2019
84
Washington
Awesome build ! How much do you have in it if you don’t mine me asking? I think you original estimate was $1,400.
That is the burning question. I bought the parts over a 12 month period, had a Dana 300
LOMAX 700
32 spline front 275
32 spline rear 450
Flip ring 75
Behemoth flip kit 375
twin stick kit 200
total 2075

More than I wanted. I hope to get her mounted up to the AX15 next week then the story will start.
 
  • Like
Reactions: Quigley

SteveBarrus

Member
Supporting Member
Jan 14, 2019
84
Washington
Build notes.

The Dana 300 tear down was fairly simple following this youtube
and sister reassembly
.

To prevent leaking of the leaky Dana 300. I tapped the shifter tube holes 1/2 NPT and installed NPT plugs along with silicone. The Behemoth front output shaft cover plugged the fwd shifter holes. All new bearings came with the LOMAX, plus 32 spline output shafts preventing the need to buy and replace. I did replace the idler gear shaft and needle bearings 19.99 from Moog.

I will be attaching a clear tube from the bottom of the rear output shaft case breather to the top breather wit a T fitting then vent it up and over the frame. This will give me a site tube to visually inspect the oil quantity in the 300.

Cheers
 
  • Like
Reactions: Quigley

High Line

Member
Feb 19, 2018
60
Tulsa, OK, USA
Don't mean to sound too pedestrian, but what's the purpose of this unless your rig is just crazy hardcore, like something competing in the Mickey Thompson Tough Truck Challenge series?
 

Quigley

TJ Enthusiast
Oct 20, 2018
153
Kingston, WA
It lowers your crawl ratio from the stock 2.72 to 4:1 in the transfer case. Unless you have the rubicon 241 case, options are limited for us np231 guys. If you do technical trails it gives you a much more controlled experience.

I took my old Cj from 27:1 to 80:1 crawl and it was a night and day experience. It turns the jeep into a billy goat instead of a hammer down and hammer some more approach that under geared people experience.
 

Willys LJ

TJ Enthusiast
Oct 26, 2018
272
Dyer TN
Now that's something I'd have never thought of considering my experience of having a D300 in a daily driver CJ5. That t/c was always a problem for me.
 

Willys LJ

TJ Enthusiast
Oct 26, 2018
272
Dyer TN
Why was it always a problem haha? My uncle rebuilt his and hasn’t touched it in years.
It was in a '80 CJ5 that I bought new so no previous owner issues and the first year for the 300. After the warranty ran out, it became hard to shift to the point I'd have to push with my leg to get it to shift in and out of low range. Got it fixed a couple of times at different transmission shops (didn't have the time to fix it myself back then), it'd be okay for a while then start getting hard to shift again. It just didn't leave a good taste in my mouth for Dana 300s.

Funny thing is that the GM 4 cyl and SR4 4spd that are claimed to be junk, just kept on going strong. Probably a Friday afternoon or Monday morning assembly at the factory. I do miss that ol' Jeep though.
 

SteveBarrus

Member
Supporting Member
Jan 14, 2019
84
Washington
Don't mean to sound too pedestrian, but what's the purpose of this unless your rig is just crazy hardcore, like something competing in the Mickey Thompson Tough Truck Challenge series?
I like going low and slow and being in control. With a twin stick and you break an axle put it in neuteral and drive it out with the front.

I will get the 300 installed next week and start getting use to her.

This jeep is my retirement jeep built the way I want it. It was basically bone stock a TJ canvas that had not been driven in over a year, 230+ miles, not running and when running not driving. Now 4" lift, 33's, rock sliders, tranny has been gone through, dana 300 twin stick, Rubicon dana 44 rear, HP dana 30 out of Grand Cherokee cv axles front. All expendable parts on engine have been changed, t-chain, water pump ..., roll cage upgraded, rock sliders. 9000 total for the jeep I want.
 

SteveBarrus

Member
Supporting Member
Jan 14, 2019
84
Washington
Don't mean to sound too pedestrian, but what's the purpose of this unless your rig is just crazy hardcore, like something competing in the Mickey Thompson Tough Truck Challenge series?
Two more reason I went dana 300 over beefing up my NP231.

1. The Dana 300 is one of the strongest jeep transfer cases built.
2. JB Conversion SYE 250, wide chain upgrade 349, rebuild kit 225, and 6 pinion planetary gear 250 = 1100 after shipping. 1000 more and I have a real beast of a case.

I still have to install and prove it out but there you are.
 
  • Like
Reactions: MallCrawlOnTons

Willys LJ

TJ Enthusiast
Oct 26, 2018
272
Dyer TN
This jeep is my retirement jeep built the way I want it. It was basically bone stock a TJ canvas that had not been driven in over a year, 230+ miles, not running and when running not driving. Now 4" lift, 33's, rock sliders, tranny has been gone through, dana 300 twin stick, Rubicon dana 44 rear, HP dana 30 out of Grand Cherokee cv axles front. All expendable parts on engine have been changed, t-chain, water pump ..., roll cage upgraded, rock sliders. 9000 total for the jeep I want.
I can relate. My LJ is my retirement Jeep. Yeah, it's old, got a lot miles and some rust, but so do I. Just doing a little here and little there. Not a bad replacement for a certain CJ5 daily driver that I've always regretted getting rid of years ago.
 
  • Like
Reactions: SteveBarrus