Ordered a new Dana 489 rear end

[TSB8C]

My rig has the original AMC20 rear end in it. When I first got it, I was told the e-brake cable needed adjusting as it was loose and didn't apply the brakes at all. But when I first got in there doing brakes, I found that the e-brake lever inside the brake drum (attaches to the rear shoe) was gone and the cable wasn't attached to anything. I also discovered some other missing brake parts (equalizer bar and spring) as well. So I became suspicious about why someone would remove and leave out such brake parts. Oh well - new 1-piece axle shafts, re-geared it, new bearings and seals, and all new brake parts (spring kit, drums, shoes, and other missing hardware). Well after only a few thousand miles, the bearing blew apart (literally broke apart) on the side where I previously discovered the missing parts, and ruined a new axle shaft in the process. So another new shaft and new bearing and seals. Now about 10K miles later, outer seal on the other side is leaking, with bearing grease oozing out into the brake drum. So I'm done with this AMC20 rear end. I was looking at doing a disc brake upgrade to it in the near future, but no longer want to spend any more money on it. I don't know if the housing is damaged (maybe a prior accident or other issue)? Maybe one or both ends are out of round and egg-shaped somehow causing premature failure of bearings and seals? Either way, it's done. I looked at some options and decided to go with a brand new Dana 489 rear end from East Coast Gear Supply. They have a lot of options to custom build what you want. Weld the spring perches in place, change the pinon angle for a lift, proper gear ratio, lockers, Limited slips, etc; and it comes with disc brakes already in place and plumbed. They claim this is truly a bolt-in swap for a CJ based on you telling them your specs (narrow or wide trac, yoke type, etc). They supply the needed u-bolts and spring plates (for the wider axle tubes) and u-bolts for the u-joint onto the yoke whereas I currently have a strap type yoke. They are about 80 days out on deliveries, so stay tuned. In the meantime, I'll keep driving this slightly leaky rear end around in Houston traffic and an upcoming quail hunt in Navasota, and just keep an eye on it. Hopefully nothing else blows apart before the new one gets here.

 

[Belizean]

Sounds good. If mine doesn’t last I would probably do something similar. Keep us up to date with how it all goes. How did you decide on that axle ?

 

[TSB8C]

I actually kinda stumbled onto it. I was looking at options to fix my AMC20 (cut off and weld new flanges on the ends, etc), pricing a disc brake conversion kit, and comparing to options for a Dana 44 . When my web searches directed me to East Coast Gear Supply, I started searching their web site for other options and came across this Dana 489 (which I was unfamiliar with). Once my interest was peaked, it came down to costs. A local shop wanted about a grand to cut off and weld on new flanges to what I have. Then another grand or so for the disc brake conversion kit, plus new bearings and seals (again). I would have to remove it, strip the parts out of it, and drop the housing off at the local shop and wait a week or so to get it back. This is my daily driver. So getting a brand new Dana 44 , but with the beefier parts and pre-installed disc brakes of the Dana 489, along with a warranty and delivery to my door, all made sense to me. I believe I can keep driving what I have for a while with no down time while I wait for the new one. Once it arrives, a few hours on a Sat to do the swap is all it will take (hopefully). Heavier duty. Four wheel disc brakes. Professionally and custom built for my application. Warranty. All worth it to me.

 

[Belizean]

I’m no axel guy, from what I have read unless a person does all that work themselves, going with something like ECGS is the way to go.

 

[TSB8C]

I’m no axel guy, from what I have read unless a person does all that work themselves, going with something like ECGS is the way to go.

Agreed. I'll change bearings, seals, new shafts. But cutting/welding flanges or mounts and getting the angles perfect, etc is not my bag. Also not interested in sourcing adaptors and parts to piece it all together when it comes to the disc brakes and spring plates and perches.

 

[Patrick]

It’s a practical solution, money well spent.

 

[TSB8C]

Well, received my new axle yesterday. Ain't she purdy? Now I have a weekend Jeep project awaiting me - yea! Here's a few pics of the new Dana 489 from ECGS. It is well crated/packaged and has all the needed hardware and accessories for what will hopefully be a direct swap for my old AMC20 . Since this axle has larger diameter tubes and larger axle shafts, it comes with new u-bolts, spring plates, and nuts/washers. The yoke is a u-bolt style and they included the u-bolts. It has disc brakes already installed and plumbed, ready for my existing rubber line and "t" connector. Now I'll have 4-wheel disc brakes. It also has new cables for the e-brake, the shorter one for the driver's side and the longer one for the passenger side. So I will retain that functionality as well. I also included a few options like the heavier diff cover with drain and the Powertrax "Grip Pro" carrier assembly. I'll provide more updates during/after the install this weekend hopefully.

 

[Belizean]

Nice ! Like those brakes !

 

[TSB8C]

Got the swap done yesterday. About 6 hours start to finish, including filling the diff with oil and breeding the brakes. Overall an easy swap, but two minor issues that weren't as plug-and-play as promised. First was get the old AMC20 out. After removing shocks and disconnecting e-brake cables at the adjuster end (not removed from the brakes themselves), disconnecting brake lines at the t-connector atop the axle housing, and the vent tube, I dropped the rear mount for the leaf springs from the shackles. Then removed the spring u-bolts and spring plates. I laid an old tarp down so I could slide the axle out once on the floor. This thing is heavy. Straight forward enough.



Now to get the 400lb new Dana489 out of the shipping crate and onto the floor under the Jeep. The engine hoist and some nylon straps did the trick. The new axle went in with no issues using the hardware they supplied (new larger u-bolts, nuts and washers, spring plates). The spring perches welded to the axle housing have 3 holes in them so you can adjust the axle slightly forward, centered, or slightly back if you need. The spring plates also have slotted holes in the center where the bolt head in your spring pack goes to also accommodate some adjustment. Then just used a jack to lift the springs back into place to put the shackle bolts back in. The nipple for the vent tube is closer to the diff on this one, so had to re-route my hose a bit to keep it off the exhaust. Then I ran into the first issue. On the AMC20 , the t-connector for the brakes (at the lower end of the rubber hose) has a 1/4" bolt that threads into a hole in the axle housing to mount it. On this axle, there is a 5/16" stud welded to the housing for the mount. Problem is the mounting hole in the connector is not big enough for that 5/16" stud. So now what?



I decided to use a small scrap metal piece to make a plate that could mount to the 5/16" stud and then provide a smaller 1/4" hole to use the original mounting bolt to mount the t-connector. I simply had to find a nut to fit that bolt. The fittings they supplied on the new hard brake lines already plumbed on the new axle fit the stock t-connector perfectly. So now all the brake lines connected up. Next was the e-brake cables. They supplied new cables to go from the e-brake adjuster curved "equalizer" and the connection on the new brakes. These mounted right up once I figured out you have to use the c-clips from the adjuster ends of the originals to secure these new ones on the caliper ends (There's no instructions supplied). But while the outer jacket of the cables were the right lengths, the inner cable part on each was too long. Even with the adjuster all the way tightened as far as it goes (until you run out of threads) the cables were still too loose. I needed a way to pull the adjuster back even farther on the threaded stud of the e-brake cable coming from the pedal by about 3 inches. So I decided to grab some scrap metal tubing I had and cut a 3" length. Removed the adjusting nut from the threaded part of the cable, slid on the tubing, and then another washer and put the nut back. Now I was able to adjust the nut to about the middle of the threaded part, and have the curved "equalizer" that the cables connect to pushed back where it needed to be to tighten the cables up.



Add about 3 qts of full synthetic 90w oil and bleed the brake lines, she's all in. Ready for a test drive today and see how it does. And BTW - I have an AMC20 with 4.56 Yukon gears and 1-piece axle shafts, all new brake parts (shoes, springs, drums, etc). e-brake cables, hard brake lines, and a slight oil leak on the passenger side now in a crate and available if anyone wants/needs it.

 

[Belizean]

Nice work ! Looks great.

 

[gert]

Dude thats pretty cool, shame about the AMC20 , it sux that the factory went out of their way to mKe it weak


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[duffer]

it sux that the factory went out of their way to mKe it weak


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Clearly a case of make it CHEAP. The 70 1/2-75 Dana 44 's were the best rear axles Jeep ever used-at least up to the new gen Dana 44 's in the JKs. Those are sufficiently different I don't think they should have ever been tagged Dana 44 's.

 

[DconZ]

What locker option did you go with? Any regrets so far on any options you went with?

 

[Patrick]

Vented rotors would’ve been enchanting.

 

[TSB8C]

Vented rotors would’ve been enchanting.

Agreed. Not an option they offered. Wonder if I can get some after-market somewhere? These are the same brakes used in 1999-2006 (I think) Wranglers with a Dana 44 .

 

[TSB8C]

What locker option did you go with? Any regrets so far on any options you went with?

I opted for the Powertrax "Grip Pro" carrier. Not a true locker, but more of an enhanced Limited slip type setup. From their web site: "The POWERTRAX® Grip Pro is the latest design in traction adding differential technology. It combines the smooth operation of a Limited -slip differential, with the strength of a fully machined, forged steel case. Using 3×2 spiral gear technology, the POWERTRAX® Grip Pro delivers progressive and variable traction. Based off of throttle input, you are in control of how much traction is applied. Great for use where finesse is as important as brutal traction is."

Since I don't do major mudding or rock crawling, but more light trails and a lot of daily road use, I felt this was a better fit-for-purpose for me. In terms any regrets, none so far. But time will tell on the choice of not getting a true locker (which they had some options available).

 

[Patrick]

Agreed. Not an option they offered. Wonder if I can get some after-market somewhere? These are the same brakes used in 1999-2006 (I think) Wranglers with a Dana 44 .

You will be perfectly fine with those solid rotors. I don’t know of any oem application with vented rear rotors and 5 on 5.5 bolt pattern. I had to modify my rotors to retain vented feature. You might want to check with Wildwood, but then this might be overkill and very expensive.

 

[TSB8C]

You will be perfectly fine with those solid rotors. I don’t know of any oem application with vented rear rotors and 5 on 5.5 bolt pattern. I had to modify my rotors to retain vented feature. You might want to check with Wildwood, but then this might be overkill and very expensive.

Thanks for the feedback. I am VERY pleased with the braking performance of the disc brakes. Very noticeable improvement with 4-wheel discs over the prior rear drums. I do have vented and slotted rotors on my 2015 Ram truck (the truck's a complete POS by the way). I added those after market and didn't really notice any major change.

 

[KRUPP]

I like it!
In your dealings with ECGS, did they ever suggest installing a new brake proportioning valve when going to rear disc? I contemplated this myself and found varying info on it. Eventually went with a new one, though don’t know if it made a difference.

 

[TSB8C]

I like it!
In your dealings with ECGS, did they ever suggest installing a new brake proportioning valve when going to rear disc? I contemplated this myself and found varying info on it. Eventually went with a new one, though don’t know if it made a difference.

They never mentioned it. But I had already installed a new prop valve when I converted to power brakes a few years ago. The valve I got is made for either disc-drum or disc-disc and is working just fine after the conversion.