489 w/power-loc ?

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318willrun

318willrun

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Looking at a 3rd member. 489 case, 3.55 and power-loc. Some of these were factory in '69?? I heard the power-locs could be a little "clunkier" but not nearly as bad as the Detroit locker?

Any experience or more details/history would be great!
 
I don't ship unless your willing to pay. but I have a fresh one. 489 new gears , fresh clutch style unit, 489 case. very nice with large joint yoke. I have the cross over u-joint to go with it if needed.
 
318willrun said:
Looking at a 3rd member. 489 case, 3.55 and power-loc. Some of these were factory in '69?? I heard the power-locs could be a little "clunkier" but not nearly as bad as the Detroit locker?

Any experience or more details/history would be great!
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I have 2 489 and one 741 case. All set up with power lock units. One of the 489’s has the doctor diff unit and the other 2 are o.e. Units. 2 are 3.23 and the other is 3.91 gear set. No complaints with any of them with the additive, although the doctor diff can be a bit ‘clunky’ on real tight slow left hand turns occasionally. I do think he sets his up fairly aggressive for harder hits. Again no complaints. Hope this helps. Swingn’
 
Swingn’71 said:
I have 2 489 and one 741 case. All set up with power lock units. One of the 489’s has the doctor diff unit and the other 2 are o.e. Units. 2 are 3.23 and the other is 3.91 gear set. No complaints with any of them with the additive, although the doctor diff can be a bit ‘clunky’ on real tight slow left hand turns occasionally. I do think he sets his up fairly aggressive for harder hits. Again no complaints. Hope this helps. Swingn’
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Thanks for sharing your experience! It does help!
 
Oldmanmopar said:
I don't ship unless your willing to pay. but I have a fresh one. 489 new gears , fresh clutch style unit, 489 case. very nice with large joint yoke. I have the cross over u-joint to go with it if needed.
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So you have one for sale. The one I'm looking at has the large yoke also. I'll ask, how much for yours? I'm sure shipping will put you over the price of the one I'm looking at, because I'm a ways from Penn. More or less looking feedback on how well folks liked the units in a 75% street/25% strip car. Are they tough? Noisy? Easily rebuilt and parts available? I've not owned a power loc, most of mine have been the typical two types of sure grips.
 
mopowers said:
Isn't a power-loc differential just another name for the clutch-type suregrip?
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I believe the power loc is a clutch type suregrip, but not the same as what we've always seen in the 742 case. That's what I'm trying to figure out before I drop money... LOL
 
318willrun said:
I believe the power loc is a clutch type suregrip, but not the same as what we've always seen in the 742 case. That's what I'm trying to figure out before I drop money... LOL
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Actually you could have a power lock (clutch type) in any of the three cases 741,742,489. Later on the cone type became the norm, they actually worked really well but would show fatigue earlier on. I used to buy brand new o.e.m units for 119.95 from I think it was mazzolini back in the early mid 80’s. These were cone style in the Chrysler box…,Swing’
 
My understanding was the 489 case had cone style suregrip, at least in late 60’s A bodies, the 742 case had the rebuildable( and tougher) clutch style suregrip. But either are fine on a street strip car
Either of those two posi types are WAY smoother than a Detroit locker, which ratchets.
I had a Detroit locker in a Duster for a while, never, ever again. Get out of the gas at speed under hard excelleration on the street( 9 sec car) and the car wanted to dart around like crazy. Darn right creepy.
Zero such issues with suregrip or spool, both very predictable, work fine.
On a mostly street car, the suregrip is hard to beat
 
B3422w5 said:
My understanding was the 489 case had cone style suregrip, the 742 case had the rebuildable( and tougher) clutch style suregrip. But either are fine on a street strip car
Either of those two posi types are WAY smoother than a Detroit locker, which ratchets.
I had a Detroit locker in a Duster for a while, never, ever again. Get out of the gas at speed under hard excelleration on the street( 9 sec car) and the car wanted to dart around like crazy. Darn right creepy.
Zero such issues with suregrip or spool, both very predictable, work fine.
On a mostly street car, the suregrip is hard to beat
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Yep 10-4 by the time the 489 was common the cone style was pretty much used….Swingn’
 
318, see Cranky's post #59 on the B side, in the thread "difference between a suregrip and a Dana power-lok.
I learned something new today. If I knew how to post his comment, I would. Looks like the power-lok is a half-assed poor imitation of the clutch type Dana unit we're used to.
 
8.75" Power-Locks were originally made by Dana/Spicer. They are the same design as the Dana 60 version, but smaller to fit the 8.75" ring gear.
 
DoctorDiff said:
8.75" Power-Locks were originally made by Dana/Spicer. They are the same design as the Dana 60 version, but smaller to fit the 8.75" ring gear.
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Are they a good unit for street/strip? Thanks
 
318willrun said:
As always... very helpful and Thanks!
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With cass coming in the rest of us can hang back. He will have more correct info than I could give. He is the one the rest of us call when we can’t figure it out..!!Swingn’
 
Swingn’71 said:
With cass coming in the rest of us can hang back. He will have more correct info than I could give. He is the one the rest of us call when we can’t figure it out..!!Swingn’
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and top notch seller! I've bought axles and other things from him. I refer him on my youtube channel to my viewers.

DoctorDiff
 
318willrun said:
and top notch seller! I've bought axles and other things from him. I refer him on my youtube channel to my viewers.

DoctorDiff
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Yep. Cass is a class act. Purchased some 4.30s, bearings, etc from him. Had questions, text Cass and he got back right away, even on a holiday! Great customer service.

Be well,
Pat
 
Had several of each type. Never any "clunkiness". The only thing I ever experienced was dragging or chirping the inside tire one some really tight units. Normally those were fresh rebuilds or fresh reconditioned cone types. Other than that, you should hear nothing as long as you use the limited slip additive.
 
RustyRatRod said:
Had several of each type. Never any "clunkiness". The only thing I ever experienced was dragging or chirping the inside tire one some really tight units. Normally those were fresh rebuilds or fresh reconditioned cone types. Other than that, you should hear nothing as long as you use the limited slip additive.
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10-4…..I should have mentioned that any I experienced was also on a fresh build, and only for a short time…Swingn’
 
Swingn’71 said:
Actually you could have a power lock (clutch type) in any of the three cases 741,742,489. Later on the cone type became the norm, they actually worked really well but would show fatigue earlier on. I used to buy brand new o.e.m units for 119.95 from I think it was mazzolini back in the early mid 80’s. These were cone style in the Chrysler box…,Swing’
Click to expand...
???
 
I'll add this too. Either unit, if working properly will "probably" chirp the inside tire around a turn under power. Under throttle, the units "lock up" a little harder than under very light throttle or coast conditions. in other words, a little tire chirp is normal under some conditions. That's the sign of a good operating unit.
 
You think mine will chirp the tires every once in a while? I bet it "might".
THIRD MEMBER1.JPG
 
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