Swap Dana 30 for Dana 27?

bluesman423 · 07-24-2009, 05:33 PM

My best friend has a 79 CJ7 with a T-18, Dana 20 and stock axles (Dana 30 and AMC 20) with a 3.54 ratio. The AMC 20 has two piece axles.

He wants to swap to a Dana 44 rear and Dana 27 (he says) front from an unknown donor vehicle. The Dana 27 is closed knuckle and both are 3.73 gears.

His reasoning is that he will have a stronger rear end and a better gear ratio.

What do you guys think? I am not sure this is a good idea.

I know nothing about closed steering knuckles or the Dana 27. The 44 and 27 were given to him. He will also be going from disc front brakes to drums. He also tells me that both will be a direct bolt in.

5-90 · 07-24-2009, 05:38 PM

Keep the D30 until you can find something better - the parts are easier.

The AMC20 has flanged shafts available with a little looking - and once that's done, the strength is comperable to the D44. And, the AMC20 is still around in some form - the HMMWV uses IFS/IRS-modified AMC20 axles at each end.

And going from disc to drum is definitely a step backwards...

SuB8HaVeN · 07-24-2009, 06:02 PM

This is the problem with everyone hyping up the Dana 44. What he probably found is a set of axles out of an earlier Jeep with a 19 spline Dana 44 rear and Dana 27 front. Obviously his AMC20 with 29 spline shafts is going to be stronger. The earlier D44s were 2-piece axle shafts anyways. Earlier D44s also had thinner axle tubes and thinner axle shafts. The closed knuckle Dana 25/27 front is a nightmare for maintenance and will make the turning radius worse than a school bus.

It is pretty common sense the axles he has under his Jeep now are going to be MUCH stronger.

JeepinYahoo · 07-24-2009, 11:16 PM

Yeah, I have an old 19 spline, 2-piece shaft dana44/dana27 combo in my 63 Scout 80...they are going to be the first thing I replace! Turing radius is great though, don't know about that one. I would consider swapping an AMC20/dana30 into my Scout before I would consider swapping my Scout axles into my CJ. Just tell your buddy to save up for some Alloy shafts for his amc20 and if he is really a serious wheeler, some chromoly shafts for the dana30. I had chromo's f/r in my TJ and they are very strong. That is the first thing I am going to do to my CJ5 once I have the money. It is expensive but also worth it, plus you can keep your stock look and stance while still strengthening the vitals.

CSP · 07-27-2009, 09:00 AM

Quote:

Originally Posted by SuB8HaVeN

This is the problem with everyone hyping up the Dana 44. What he probably found is a set of axles out of an earlier Jeep with a 19 spline Dana 44 rear and Dana 27 front.

x2.

Not all D44's are created equal.

jeepdaddy2000 · 07-28-2009, 10:09 AM

Quote:

Originally Posted by SuB8HaVeN

This is the problem with everyone hyping up the Dana 44. What he probably found is a set of axles out of an earlier Jeep with a 19 spline Dana 44 rear and Dana 27 front. Obviously his AMC20 with 29 spline shafts is going to be stronger. The earlier D44s were 2-piece axle shafts anyways. Earlier D44s also had thinner axle tubes and thinner axle shafts. The closed knuckle Dana 25/27 front is a nightmare for maintenance and will make the turning radius worse than a school bus.

It is pretty common sense the axles he has under his Jeep now are going to be MUCH stronger.

While I'm not advocating the swap, he might want to take a good look at the D44. If it is a 70-71 30 spline flanged axle assembly, it would be worth something to the ECJ5 crowd. If the axles are solid, he can sell them and use the cash for other upgrades.

**80cj** · 07-28-2009, 10:52 AM

If the 44 is out of a pre-72 CJ, it will have an offset diff originally used with the D-18 T/C. Going to a D27 would definitely be a downgrade. The axles are 10 spline vs. 27 of the 30. The spindles on D27's are secured by bolts threaded into the knuckle which pull out at times. A popular fix for this is to convert to the pressed in studs used on D30's or swap in a D30.

hotrod351 · 07-28-2009, 11:06 AM

i bought my 1955 M38A1 over 10 years ago, came with dana 25, 10 spline front and 44, 10 spline rear, also has a 350 sbc, well i put a lockright in the rear and a powerlock in the dana 25, ive been four wheeling all over the place, mostly rock crawling, with 33" tires and also in the sand, ive never broken anything and have to say the 5:38 gears are great, ofcourse i also have a warn overdrive, as for going to drum brakes, well i have the drum brake upgrade, 12" front, and it works good but your friend could do a disc brake upgrade on the dana 27 front, theres plenty of sites that tell you what parts to get from the wrecking yard and how to convert it. ive never felt a need for it myself.

**80cj** · 07-28-2009, 07:45 PM

I personaly can't see the logic in ditching a 30 and replacing it with a 27 then doing upgrades to the 27.

nshefbuch · 07-28-2009, 09:10 PM

i second that 80cj. i have a d25/d44 in my 62. i think you would have to upgrade the d25 to equal a stock d30
i too have 5.38 gears and do love them. 10 spline fronts are way to weak and of course the two piece rear axles suck too. yes their are plenty of websites for upgrading the old stuff but the money would be better spent replacing the axles in my opinion. hermtheoverdriveguy.com has lots of upgrades for the older stuff. i run 33" tires and am pushing the limit of my axles. only reason i don't pop axles all the time is i'm still running a 4 cylinder. i find it real hard to believe these axles would hold up with a v8.

SuB8HaVeN · 07-29-2009, 04:09 PM

You wouldn't believe how many trashed D25/D27 carriers I've seen. When I bought my wagon, it had a grenaded Dana 25 front. While searching for a carrier out of parts Jeeps in my area, I came across quite a few that had broken carriers because the metal is so thin at some places. The D27 ring gear is even smaller than the D25, but used more bolts to mount it to the carrier than the D25. If you're building an original old school Jeep I'd keep it, but IMO there's no comparison between the D30 and D25/D27.