With a Sure-Grip Unit and a 489 Carrier Case


I want to build a complete drivetrain for my Fury

– or maybe for another Mopar that im gonna buy – with decent performance and all new components, preferrably build by myself. I already have a 440 Bigblock and a 727 tranny that im gonna rebuild but I’m gonna start with the 8.75 rearend. I was searching the internet to find an 8.75 rearend that came from a late C-Body style car, so the lenght would be a direct bolt-in for my Fury without to much hassle.

The Fury now has a good – but weaker – 8.25 rearend that will be replaced with the 8.75 rearend.

I found a 8.75 housing without carrier on Facebook that came of from a late C-Body and it also had the axles to go along with it. Picked it up and that was basicly the start of the build.

The complete rearend housing, all rusted and dirty

489 Case & Ring gear


The next step was finding a 489 carrier case for the housing. The 489 carrier is the strongest case for the 8.75 rearend, so obviously I wanted to go with that one. And I had some luck there: my friend Mario had a complete 489 case laying around and he also had a new bearing set and a 3.23 ringwheel and pinion gear. The 3.23 gears are perfect for me so I purchased all the goodies from him with a big smile on my face.

The 489 case came with old gears but will be removed as I planned to install a new sure grip unit in there. Finding the sure grip unit was next!

Bearing set with crush sleeve (which I did not use)

489 Case with old differential still in it

Sure Grip


I visited my favorite shop in Holland – Sixpack speedshop – to see if they had a sure grip unit and they had brand new units in stock. So I purchased the sure grip from them, along with a gasket set and oil. Ordered a crush sleeve delete kit from Doctor Diff to eliminate the crush sleeve and as soo that arrived, I had all the goodies for the 489 carrier case build.

Meanwhile, I send the housing and the carrier case to a blasting company. Had it sandblasted and epoxy prime so the rearand housing looked like new.

Fresh sandblast and epoxy primer job

New Sure-Grip Unit

Applying paint to check gear settings

Setting sidelash & backlash with precision meter

Axle Bearings & Disc Brakes


The housing had the axles with them, but after inspection, they weren’t all that great. They had welds on both of them and when I removed the bearings, alot of grooves and cracked were shown, so I decided not to use those and ordered brand new axles from Doctor Diff. I also ordered rear disc brakes, bolts for the case and longer wheel studs and everything was delivered fast by Doctor Diff.

On top the new Doctor Diff axle with green bearings and below my old and worn out axle

Complete 11.25 inch rear disc brake kit from Doctor Diff

New axle seal

You can see the handbrake pads that will grab into the discs

Final Assembly


The assembly went smooth and everything fitted the way it should without any problems. The new Doctor Diff axles came with green bearings that were already pressed on the axles so installation of those went smooth. I mounted the rear disc with calipers, taped everything off and spray painted the entire rearend black.

And here it is: The complete rearend with all new components!

Complete with my Epiphone Les Paul guitar

The Video

Yep, I shot it all in chronological order.

Along with some hard hitting riffs from the stoner band “Sleep”. Enjoy the video and thanx to my friends who made this build possible!

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