489 case used value?

C-Sick

Member
Joined
Jun 13, 2019
Messages
100
Reaction score
121
Location
Edmonton Alberta
Browsing for parts I probably don't need anytime soon, and ran across a local ad here for a Mopar 8.75" center section. 489 case, 3.91 gears and an open carrier. I can get it for $250 cdn...

Pro's for me is the 489 case, and the price, but that's about it I think. The 3.91's are a little deeper than I want, and the open diff is obviously a downer.

What do y'all think?
 
It is supposed to have the strongest gear set because of the pinion shaft, it's a good price, you could always sell the gears. I never looked but does anyone make a locker for the open diff?
 
That is a good price for a nice street gear. A Sure Grip would be nicer, but more money.. Sure Grips run from $500.00-$1000.00.
 
The crush sleeve on the pinion is the weak point (?) or so I've heard. A friend like the 742 cases, slap them together and go, no fiddling around. But there is/was a crush sleeve elimination kit available. I have the 489 for my Dart, in a 3.23 open and 4.10 SG flavors.
 
Lock Rite makes a lunchbox locker for the 8.75, but it's not cheap enough that I'd choose it over a full case. Lowest I could find was a hair under $400 US.

I'd much rather use the Sure-Trac II from DrDiff for $545

Mopar 8 3/4" (8.75) Helical Gear Sure-Grip ("Sure-Trac")

I've also seen the crush sleeve eliminator kits on Summit and the like for around $30

It is cheaper than buying a new bare 489 case.
 
742 is the best case. It has the largest pinion bearings and no 90 degree step in the pinion gear. Crush sleeve is only good for the assembler. Saves time so they went for it,

On the for sale 489 the value is the 3.91 gears. If you don’t need them then look for a 2.76, way more common,
 
There is a crush sleeve eliminator, but if you never bolt slicks to your car your wasting effort eliminating it, if starting from bare case sure what the hell. The 742 is a big one but uses same yoke/splined section as 741 and 489, so where is the strength? Deflection in the pinion shaft and or against the larger big bearing, okay maybe, but again you need to dead book the tires, heavy car, and a shock like a trans brake, if your using those your way beyond a 8.75 Chrysler rear.
Best money spent is any rear with gear you want and just put in a clutch type sure grip from Dr. Diff for $395 plus bearings. Swap it into your center and go. BTW if your car has stock driveshaft and 7260 u joints those will break first. 7290 u joint is okay, but the small 1/4" bolts and straps become the weak link.
Bottom line is without slicks and very good traction (think very sticky drag strip starting line) you are not really going to strain any of the 3 different center sections.
 
Bottom line is without slicks and very good traction (think very sticky drag strip starting line) you are not really going to strain any of the 3 different center sections.

Couldn’t agree more. All of this “I’ve gotta have a 489 case because it’s the strongest” crap has become way overblown over the last 15 or 20 years. Go ahead and try to break a 741 unit on street tires then report back.

As far as the OP’s question, yes, that’s a fair price.
 
Go ahead and try to break a 741 unit on street tires then report back
After 30 years (of course I did switch from a open to a sure grip about 15 years ago) a crap load of dragstrip passes on 3 different engines and wearing out a trans that rattles your teeth when it shifts, my 741 is still hanging in there.
I would buy that center with any gears for $250 cdn
 
I mean, if you're interested in trading I have oem 489 2.76 or 3.23 (I'd have to check) gear sets. I'd only be interested if the 3.91 is also an oem gear set.
 
Although it won't be immediate this car will be trans braked, 2 step, slicks etc. I've been pricing 9" rears, all new and it's not as pricy as I was expecting. I don't want to spend money twice on stuff if I can avoid it. This was fairly cheap, but it doesn't help me if I'm honest.

I appreciate all the good info on the 8.75"!
 
Back
Top