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Comanche disco Dana 30 swap or not

N

Nodrama43

NAXJA Forum User
Location
Southern Ohio
is there any advantage to swapping out the original HP Dana 30 (with vac disco) in my 1990 MJ eliminator for a non vac disco HP Dana30 from my 1999 donor XJ?

I have spare one piece axles and am also thinking about a plate and seal conversion.

any pro's or cons?

the truck is getting a 3" lift with 31's and either 3.73 or 4.11 gears.

running gear is 4.0 engine, Ax-15 with factory Dana 44 track lok in the rear.
 
disco axle housing has a stronger UCA mount.

non disco housing is a stronger tube because it's not got the cast piece in the middle.

I'd to the non-disco one and box the passenger UCA mount so I felt good about life and roll on.
 
Gear the non-disco axle, or find a 4 cyl XJ with a 4.10 geared and it's plug n pray.
 
as to gear ratio.

3.73s and 31's is pretty much spot on for factory revs/mile.

I'd do 4.10s if you're going to take it off the pavement.

4.56's if you're actually gonna wheel it proper.
 
I have decided to keep the disco housing but swap in a one piece axle and block off plate. Keep it original looking. It will get a Yukon gear 4.11 ratio r/p set with a tru-trac.
 
I know you've already decided, but in the long run you'll probably be better off with the non-disco housing. You won't have to deal with extra seals. Plus if you ever want to upgrade your steering, truss it, or build a nice HD 3 or 4 link that cast upper control arm mount will always be in the way. Trust me in a few years you're going to want to make changes to your jeep, we've all been there, once you begin to modify it you'll never stop, lol.
 
One of the deciding factors to leave it as is for now is the fact I wanted to sell the 99 XJ that was to be the donor for the HP Dana30 for the MJ. That dana 30 was so rusted into the XJ that I am sure everything would have either broken or needed cut out. My initial reason for buying the 99 XJ was to rob the three factory skids off it for my 2001 XK that I am currently lifting/gearing. I already have a completely rebuilt HP Dana 30 that I am putting into the 01. I took the skids of the 99 yesterday and sold it to a buddy down the road from me so it is gone.

I need to start a build thread on my MJ. It was an incredible find in Colorado and was formerly owned by Yellaheep. I have plans to keep it mostly stock with a mild lift and some engine performance upgrades.
 
yes, he had a few.

where in southern ohio?
I'm in Ashland, and have piles of parts.
 
well that's about 4 hours fro mme, so casual meet ups are out, but if you need a weird part hit me up.
 
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