dana 300 t-case

[superj]

I always hear people say to get a dana 300 t-case and never would have ever wondered a thing about one but a very good looking unit came up for sale by me for 200 bucks. And I mean beautiful unit, no dings or marks, and clean on the outside. Came out of an 80 cj5, if I remember right.

Now looking at it, it is a passenger drop t-case. How come so many people say to get those if we canot use them on our driver drop yj?

Now I could be wrong on the year model it came from so don't get to picky on that, just tell me what's the haps on this particular unit. I know its a 300 because the metal tags are still easily readable on it and it says dana big as day on the case above the tag

 

[82cj7son]

i have a d300 transfer case and it's strong as hell. for cj7's it's a great t-case. if you can pick it up and use it I'd recommend it...

 

[xjmarc]

They make flip kits so you can run them as a driver drop but most don't oil well and leak. They are great cases, strong and no chain to wear out but not great for wranglers unless you plan on an axle swap, cutting up the floor and redoing your exhaust.

 

[superj]

ok, that is what i couldn't understand is how come everyone was saying get them but it looks like a lot of work to fit a wrangler.

 

[Bounty__Hunter]

What's the low range of the d300?

 

[jps4jeep]

2.32:1 low range, np 231 is 2.76:1 for comparison.

Here is my low down on a Dana 300; better than a Dana 20 t-case, but there are a number of weaknesses; the cases can develop stress cracks, puny front and rear outputs (19 spline I think) low gearing is not ideal, as mentioned if you flip it, it will leak and you will eventually starve the gears for oil, prone to shock loading the shaft and it snapping at the rear bearing detent.

There are a number of gear driven cases that are better strength wise, but none are geard as low, the np 205 is a miserable 1.7?:1 and the 203 is no better.

Manufacturers went to chain driven cases simply because that have a "shift on the fly" capability and they are a lot quieter.

In order to make a D300 really strong you need to install

4:1 tera lo kit
HD rear output
HD front output
better rear bracing to a cross member

If you really want to throw cash away; Stak makes a replacement billet case.

once you've done all this; you're at the price of a Atlas II case. Lastly, $200 for a case is a little on the high side, if it is as clean as you say it is, maybe I would spend that, remember the newest D300 is now 25+ years old and most people neglect maintenance on a T-case.

 

[superj]

ok, thats why i asked. i had heard all this stuff about them but knew nothing.

i am staying with my 203, i think is what is on mine. what ever came stock in 87

 

[Bounty__Hunter]

i am staying with my 203, i think is what is on mine. what ever came stock in 87

You likely have the np207, or slight chance of a np231 if it's a late '87.

Your best upgrade on the cheap would be a 231 from an '88+ Jeep. There's a lot of aftermarket support including SYE kits, 2lo, wide chain and sprockets, 6gear planetary, 4:1, etc.

 

[superj]

your right, np207. to me its not worth the hassle to swap the transfer case

 

[Bounty__Hunter]

Correct, if everything works as it sits. But if you lift to 4" as most eventually do I would consider a 231 with a SYE kit.

 

[superj]

oh ya, if i ever do that then i know i would have to because i have noticed the lack of support for the one i have. my jeep is a march of 87 model so i have to 207. i looked at it but had forgotten the numbers from way back when i checked it. i knew it wasn;t a 231 though because i have done that swap on another jeep previously so that number is easy to remember