81 cj7 rebuild by nixer600

By diyauto
( 3 )

3 minute(s) of a 67 minute read

9-8-2012

Thanks, for the comments, one thing has stayed the same since we have owned this thing now for around 12 years, I have never hesitated to use it for all it's worth.

Heck the dana lp 30 may have lasted me a long time if I had not had it in 1st gear 6.32:1 tranny gear with 4.56 ring gear locked Detroit Yukon cromo shafts 760 joints to 36 12.5 15 super swamped SX (super heavy)  

I was crossing the creek at night christmas eve 4 am in north Florida no top on the jeep 4 other vehicles on the trails with us, the water was flowing thu the doors and up to my knees (it was freezing out, it was sleeting badly for here) and I was like man I don't want to get stuck in this smelly cold creek swamp mud thing I'm in, at this point I was already spinning tires against old bridge pillings in the water that I did not know about, so bad Idea floored it for
What seemed like 3 seconds or so, then the front end snatched straight up, i remember seeing headlights in the tops of the trees, the still Floored jeeps, front end came down on the dry bank on the edge of the creek! The steering felt funny for a second and then I drove out and then every 5 feet or so the jeep would bind up, and then power thru it. I assume ring gear lost some teeth I'll let ya know when I open it up.

I wish I had not broken the front end so quickly cause I would have liked to report on how strong it was. But my story is clearly shows that a poor judgement call broke the diff. We have no rocks here and we need wheel speed for deep sand and sandy black mud, heck we don't even have the heavy clay mud, so I figured I'd get long life out the Dana with my i6. Stupid beer, and adrenalin combined with fear of getting stuck in cold water. Ohh well lesson learned, (it was private land)


This is some pics I took of the LP dana 30 ring and pinion gear, showing its size in relation and ratio. I know as the gear gets numerically higher the pinion gets smaller, this is critical on a small gear set, I always wished I went with 4.27 instead of the 4.56 thinking that would have made things a little stronger, if you have measurements of a Dana 30 similar to these Post em up sober can see how contact patch changes as the gear ratio does.

Any one know off hand what gear would be the strongest ratio, in a Dana 30 my Luck like some 2.76 or something useless.

Just a strange fact I've always thought about but never researched.

This week I'll post some pics of the front Hp 44 and read ford 9 inch I picked up. I'll prolly sell the 9 inch or trade it off for work on my jeep. I have a body paint guy...





Comments

Nice build!

Posted by Diggymart on 1/21/21 @ 10:34:00 PM