Axle Swap, Or Not...noob Question.

I’m picking up a (pretty much) stock ’64 CJ5 and would like some opinions on upgrades. The first is disc brakes and I’m looking at 2 paths:

1. Just add them to the Dana 27. The most tire I can ever imagine is a 31, and I’m not aggressive.

2. Find a Dana 30 nt with disc brakes ad swap it in.

What are pros and cons of these options? Power steering would be next, if that has any relevance. Thanks!

 

11" drum brakes are another option that works well with the factory axles. The main advantage of the 30 is you get the better brakes, tighter turning radius, more strength and durability, and much less maintenance in a single package. The only way you could avoid a gear change for the 30 is if your CJ has 4.27 axles now and you find a '72-75 axle with optional 4.27 gears... which only comes with 11" drums.

Typically a closed-knuckle Jeep that has not been owned by an enthusiast will need the front axle gone through ... seals, king pin bearings, pre-load, maybe stud repair. If you want to do disks at the same time, you'll get plenty of help here regarding the axle maintenance and the brake upgrade.

First post! Welcome from Boston!

 

Welcome. The open knuckle 30, as stated above is probably the best route. If a gear change is out of your budget though, it sounds like the 27 will survive what you do. Either way, the knowledge from the others on this forum is incredible.

 

From what it sounds like your use will be, I'd just do the disc brake conversion on the D27. It's a fairly easy conversion. If you can't find what you need here, search the JP Magazine online site. It has a parts list, although I believe you can find everything here that you will need as far as information. As noted above, you may be able to find a D30 with the proper gear ratio, but it isn't likely. When I swapped out my D27 to an early D30 I just swapped the disc brakes over as well. It's easy to swap the GM style discs over to a pre-disc brake D30 if you decide to upgrade later.

 

Wow, what a great response! Thanks! I think I'll start looking for a D30 and use the D27 as a back up plan. As far as the gear swap on the D30, are they 'plug-n-play' and available, or is there machining to do?

 

D27 and D30 axles will require different tie rods and drag links and possibly pitman arms when you decide to do the Saginaw mod.
Power and Manual Saginaw systems will mandate the use of different pitman arms.
So I'm suggesting you make sure which model axle you want before you start.

 

No machining, just parts replacement. Maybe you don't understand what's involved with a gear change? It's quite advanced for an amateur mechanic. You need new gears and an installation kit, and some special tools. New gears will be about $300, installation kit maybe another $150. A shop could charge you maybe $300 labor if the axle is out of the Jeep, plus the parts. Just to give you an idea of what's involved. Take a look at the TSM for '74 or '76 here Jeep® Parts Manuals online for some more detail. Randy's RANDYS Worldwide | Differentials, Rear End Gears, Axles, Lockers is a good place to look up the parts.

 

How could you tell? lol Thanks, this is a good education. Hopefully it won't turn into a basket case.

 

I am in the middle of a D30 swap. (thread here) D30 Upgrade
It is not necessarily cheap to swap a D30 depending on what axle you find. Like was stated above, if you find the correct geared D30 it is much easier and cheaper. I am into my D30 for right around $1,000 and I was able to get some screaming deals on parts. The ARB I picked up normally goes for about what I am into the axle for.
I am currently running a D27 with disc brakes and it works really well. If you compare the cost of the disc swap to a complete rebuild of a D30 the D27 is the way to go. The only reason I am doing the swap is 1.mentioned above, 2. it was "free" and 3. the possibility of going to 35" tires one day.

 

FWIW, I used the stock steering on my D30 swap.
It still will not be cheap to swap in the D30. Chances are you will need to do a complete rebuild of that axle too. New axle U joints, new spindle bearings/seals, new hub seals, new pinion seal, and perhaps inner axle seals which are a real joy. Not to mention the cost of swapping out gears. You might need a new case (depending on the ratio), ring and pinion gear and a differential setup kit.

Personally, I would stick to the D27 if you are not going to be wheeling it really hard. Just slap on some disc or 11" drums and some new parts that tend to wear out and enjoy. I agree with the others, a dual MC is a must!

Only reason I went with a D30 is that I wanted a "stock" looking flat fender with ox lockers hidden in there.

 

Welcome from Ga.

 

Thanks for that. I've been looking hard over the past few weeks and nothing has shown up locally. There have been a few good deals on nearly complete donor vehicles, which might not be s bad way to go. BTW, had a '53 m38a1...loved that jeep!

 

I would not pass by a '72-77 axle with drum brakes. The 11" drum brakes are very effective for that size vehicle, and service parts are plentiful and cheap... we've had many discussions of the relative merits. Indeed, 11" drums on the 27 would also be a big, big upgrade, and bolt-on easy. It seems the 11" backing plates are getting more scarce... but they are out there if you look around.

 

Welcome from Michigan,

 

To piggyback on what timgr said above, it's actually easier to convert an early pre-disc brake D30 to disc brakes than the D27. Essentially using the same parts as the D27 conversion. I've never had the 11" brakes and I'm sure they are much better than the 9" drums, but what about after they are dunked in a creek or other water source. I imagine the 11" brakes aren't much better than the 9" when wet. If running through water isn't in your trail plans then I'd guess the 11" drums would work fine. But, there is a reason that you don't see drum brakes on many vehicles anymore.

 

Posi, regarding the 11s and water.....engaging the brakes while fording water helps keep the water out...at least that's what I do.

 

My 11" drums work fine after going through water. Like stated earlier, the size of the brakes compared to the size of the vehicle is very effective. They do dry out pretty fast.

 

I did a D30 swap in both mine and my dad's flatfenders and most recently my CJ-6. Both Flatty's got disc brakes (easy) and the 6 got 11" drums. The 30 that I put in the 6 was a bare housing that was free, I had spare knuckles, the correct gear ratio, axles, and back plates and drums. I also got a free Air Locker for it like JZebers. But it still ended up costing me a bit over $400 in ball joints, brake soft parts, U-joints, steering, driveshaft, etc. Don't get me wrong, A D30 opens up a ton of locker options, is stronger, and has better brakes than a D27 whether it has discs or drums, but if you're on a budget, convert the D27 to discs or 11" drums and run it. All those parts will swap onto a D30 later if you decide you need one.

thread here- New Perkins CJ-6