What would you do with a 8 3/4 489 that was given to you?

[Weak440]

I have a 489 center section with a bad limited slip (worn out) and a bad pinion seal (was told it leaks like crazy). But, the bearings and 3.23 gears are supposed to be good (used obviously).

I was thinking of replacing the limited slip unit with a Detroit Truetrac Differential and replacing the pinion seal. I am going to have to change from the 7260 yoke to the 7290 that I use any way.

I really want to keep the 3.23 gears - What would you guys do?

 

[S/6nt-SIX]

I took the middle vote, but honestly my decision would depend on the motor/trans that was pushing this. Also what I was using the car for (drag, cruise, or daily)

 

[cudascott]

Give it to someone else :happy1: I went with the middle

 

[Weak440]

It is eventually going to go in a '74 Duster with a mild 440/727 that is mostly going to be street driven and occasionally driven to the track.

The 489 has a crush sleeve in it doesn't it? I have a feeling that pulling the yoke is going to cause me problems with it?

 

[chooch]

personally i'd pull the guts keep the case & start over new why would you want to deal with 30+ year old parts including the gears that you know nothing about especially when you have a nice reliable street driver car???

 

[69MOPE]

Take it apart, clean and paint the casting, inspect the gears for wear, inspect the bearings for wear, install a solid pinion spacer, replace the sure-grip with a power lock unit with new side carrier bearings and that 440 with the right convertor will love it.

 

[a1972dartswinge]

I second 69MOPE, the power lock unit it so much more reliable and will hold up better. Pull apart and check old parts and re-use the bearings if good, but you'll need the conversion bearings for the end caps to go with a power lock posi in the 489 case. Mancini carries all of this.

 

[bsad67]

i second 69mope, the power lock unit it so much more reliable and will hold up better. Pull apart and check old parts and re-use the bearings if good, but you'll need the conversion bearings for the end caps to go with a power lock posi in the 489 case. Mancini carries all of this.

x3

 

[SGBARRACUDA]

If you decide to replace the original SG, I would be interested in buying the old one. I vote on the middle one too.

 

[Weak440]

Thanks for the help guys! I am going to start collecting parts and tare in to this project in a couple weeks. I will keep you guys posted because I am going to be asking lots of questions!

Thanks again!

 

[hotrodhoodlum]

If its not broken don't fix it............. replace only whats necessary to suite your needs

 

[Ted Carlson]

Sorry that I don't remember who, but someone posted a while ago that they would machine the end of the cone so it could move enough to work. I think that it would be OK for a mostly street car.

 

[Weak440]

Hmmm... That sounds familiar - I may have to look in to that. Thanks!

 

[sireland67]

Sorry that I don't remember who, but someone posted a while ago that they would machine the end of the cone so it could move enough to work. I think that it would be OK for a mostly street car.

X2 you just need to fresh up the clearences in the cone sure grip.
Take about .030 off the cones and put a .030 shim behind them.
Any Ma / Pa machine shop with a manual bridgeport can do this for less than a $100.00.

I am getting ready to do the same thing with my used $60 2.76 489 case open.
Converting to cone sure grip used $150.00, with a new 4.30 gears and install kit.

I will have about a little over $550.00 in a fresh center doing the work my self, if you have to pay somebody add a couple hundred bucks.

 

[bkd]

Deleted...I didn't help....just said you could give it to me......sorry that's why I deleted it

 

[74DartSwinger360]

If you get rid of the sure grip Ill buy it off you. But you should just pull it apart and replace the bearings pinion seal and rebuild the sure grip.