8 3/4 rear end question

[rlipp69]

Hello i am resorting my 68 barracuda convertible. I was just wondering how difficult is it to change the gear in my rear end? Also is there a special lube i need to use . There is no suregrip tags on rear end but both tires turn in the same direction so I am assuming it is a sure grip.

Thanks

 

[cosgig]

Changing the gear in an 8 3/4" is as easy as pulling the axles out a little and removing that entire center section you have pictured and replacing it with a complete center with the desired gear already in it! Then push the axles back in and adjust them and you're back on the road! A reasonabley saavy Mopar Guy could do that procedure in a couple hours!

If you just want to change the gear in your center section, that involves disassembling the entire center, removing the pinion gear, ring gear, crush sleeve, and putting it all back together with the correct lash on the gears on the crush sleeve preload, not an easy rehab!! I guess you could get the new hard spacer and shim it, but you still need some pretty extensive knowledge about rear assembly!

 

[TrailBeast]

changing the gear in an 8 3/4" is as easy as pulling the axles out a little and removing that entire center section you have pictured and replacing it with a complete center with the desired gear already in it! Then push the axles back in and adjust them and you're back on the road! A reasonabley saavy mopar guy could do that procedure in a couple hours!

If you just want to change the gear in your center section, that involves disassembling the entire center, removing the pinion gear, ring gear, crush sleeve, and putting it all back together with the correct lash on the gears on the crush sleeve preload, not an easy rehab!! I guess you could get the new hard spacer and shim it, but you still need some pretty extensive knowledge about rear assembly!

x2

 

[ir3333]

I've heard changing a centre section is more difficult when you're on the wrong side of 60 and lying on a creeper
..there should be a splotch of orange on the filler plug if it's a suregrip,but it could be long gone.

 

[TrailBeast]

I've heard changing a centre section is more difficult when you're on the wrong side of 60 and lying on a creeper
..there should be a splotch of orange on the filler plug if it's a suregrip,but it could be long gone.

How about on the right side of 60 and lying on gravel?

 

[AJ/FormS]

Hey, I resemble that remark. I'm 62, and if I felt the need to swap chunks I would slide right under there and do it.
Every streeter should have at least 2 chunks. Unless you have a 5 speed. At one time I had eight, with a 4spd.
I installed a drain plug in my banjo; so 65 minutes on a hoist, from the time the drainplug goes back in. A lil more, if laying on your back, and feeling around for tools.

Rear ends shipped from the factory with a SG had a large X cast into the carrier. I seem to remember the X being around the filler-plug.............In addition to the tags.

 

[rlipp69]

Thanks folks. If i want to top off the rear end is there a oil recommendation and do i need to add skunk oil when I'm just topping off.

 

[pjc360]

Thanks folks. If i want to top off the rear end is there a oil recommendation and do i need to add skunk oil when I'm just topping off.

Most of the newer synthetic 75w-90 and 75w-110 and 75w-140 already have a limited slip additive in the fluid, I know valvoline synpower does in 75w-90 and 75w-140, same with Mobil 1 and amsoil and redline ect ect.
I'm running valvoline synpower 75w-90 in my 8 3/4, but it's a 741 case with open 3.55 gears.
I would have confidence in the valvoline synpower in a sure grip unit as well.

 

[mguner]

or the back side of 30 with... Oh wait... With the 489 housing it is a little simpler changing gears because of the crush sleeve but there is always a chance you get one that was machined a bit off compared to your donor. I have been very lucky over the years in keeping the shims from the gears that came out of the housing and using them on the set going back in. Even with a bearing puller and a press you may end up having to buy a new inner pinion bearing as they are easy to destroy when pulling them. The lash is pretty easy to set if your depth comes out good. Just make sure you keep good preload on the carrier bearings.

 

[replicaracer43]

Hey, I resemble that remark. I'm 62, and if I felt the need to swap chunks I would slide right under there and do it.
Every streeter should have at least 2 chunks. Unless you have a 5 speed. At one time I had eight, with a 4spd.
I installed a drain plug in my banjo; so 65 minutes on a hoist, from the time the drainplug goes back in. A lil more, if laying on your back, and feeling around for tools.

Rear ends shipped from the factory with a SG had a large X cast into the carrier. I seem to remember the X being around the filler-plug.............In addition to the tags.

I disagree with the statement concerning the "X" casting........ the "X" is cast into the "741" housings and has nothing to do with sure grip or not..... Any of the housings could have a suregrip, it was a paint splotch and a tag that signified that.