This should dispell the 8 3/4 myth that's been around for so long......

[Daves69]

Does anybody know if any early (1968) 489 cases came from the factory with clutch type Sure grips instead of the cone type?

You might check through the TSB's here..........
http://www.hamtramck-historical.com/library-2.shtml

 

[dadsbee]

They are all only as strong as the smallest diameter... and with that said they are ALL the same at the front bearing. The 742 and 489 are probably the weakest from a design stand point due to stress risers from the machined step down to front bearing diameter. It is also nice that you can pull the yoke off and on the 741 & 742 to change the seal without fear of messing up the bearing preload.

 

[YY1]

You guys that said you don't like the 489 because of the cone SG-
Do you realize the SG unit is totally independent and interchangeable between the case and ring and pinion sets.

The R&P and the case casting are what must match each other.

Also- 3.55 gears for 741 cases should be relatively easy to find.

 

[wyrmrider]

http://www.hamtramck-historical.com/_1965Hi-PoParts-01.shtml?load_img=9

 

[beanhead]

I always heard a 489 with a solid spacer instead of the crush sleeve was the strongest, since it already had the largest pinion stem diameter (besides the Dana of course..) but then I've never broke any of mine--lucky! The cones just aren't as rebuildable, right?

To clarify my earlier post, I wasn't comparing the Dana to any model of 8-3/4...it's legendary for a reason!

 

[GrabberOrange69]

Interesting, thanks Cranky.

Anyone know what the lowest gear sets ma mopar put in the 741? Aftermarket looks like 3.73 is as steep as you could get?

 

[33 IMP]

I'm guessing here, because I don't know for sure which case, but a 7.14 (or 7. 17) was available in 300C Chrysler in1957. How low do you want to go? (Even if you wanted those ,good luck finding them). As someone (sorry, i would gladly give credit, i just don't recall who)said, maxwedge used 741 cases, the can't be too flimsy.

 

[big_shmoop]

http://www.doctordiff.com/blog/tech-info/rearend-pinion-comparison/

The article starts out by saying.....All Chrysler 8 3/4″ rearends are good all-around designs, with none having a significant design advantage over the others. The 741 case 8 3/4″ has unjustly earned the reputation as a “weak” rearend, which these pictures will dispell.

Click the link and read and see what he's talking about....and me! Now all we need is an article about the cone vs clutch units lol

Where have I've seen this link before...

When read it a while back I saved it for my reference library.

 

[wagonman]

You guys that said you don't like the 489 because of the cone SG-
Do you realize the SG unit is totally independent and interchangeable between the case and ring and pinion sets.

The R&P and the case casting are what must match each other.

Also- 3.55 gears for 741 cases should be relatively easy to find.

Yup E Booger did a write up a while back. Good Info.

 

[wagonman]

Been thinking of putting the 742 323 SG on the shelf and getting a 276-294. Not for fuel mileage ( cant hurt ) but to lower my interstate RPMs and play with some High end imports ie Porsche ect on the freeway. Plus some longer burnouts too.

 

[Bruce J]

I still say a 742 and 489 will maintain a better contact pattern. I have all three housings, plus the aluminum housing. And I forget which pinion design it uses.

 

[Cranky]

Interesting, thanks Cranky.

Anyone know what the lowest gear sets ma mopar put in the 741? Aftermarket looks like 3.73 is as steep as you could get?

Not sure about that but pulled many 3.91's out of old pickups over the years. I'm thinking they were pretty common thing for the factory to build them that way. When I went into the AF in 71, my permanent duty station in Germany had a fleet of 71 Dodge pickups that all had 3.91's. Thought that was somewhat odd since they were being used to make runs between other bases and that meant they spent time on the autobahn. The trucks had 318's in them and they didn't like running 80+ mph very much lol. The AF had a maximum speed which was much lower than that but anyone who has ever driven the autobahn knew that driving slower than 80 mph could be a safety concern....and no one drove that slow.

 

[YY1]

LOTS of A and D series trucks built with 225 and 3.55 or 3.91 axle in 741 case.

 

[Darter6]

3.91 was common in the Vans too. I pulled a 741 with 3.91 out of a 66 Dodge van.
I truly believe that the aftermarket quit making many ratios because of the myth of the 741. 20+ years ago I did a 741 and was able to buy 4.30.It was still in my drag car with god knows how many runs that I sold 6 years ago.I did wear out a Aurburn cone unit in it and then went to a spool. I have no problem using the 741.Same goes for(even though we aren't discussing them) 7260 U-joint..

 

[Cranky]

3.91 was common in the Vans too. I pulled a 741 with 3.91 out of a 66 Dodge van.
I truly believe that the aftermarket quit making many ratios because of the myth of the 741. 20+ years ago I did a 741 and was able to buy 4.30.It was still in my drag car with god knows how many runs that I sold 6 years ago.I did wear out a Aurburn cone unit in it and then went to a spool. I have no problem using the 741.Same goes for(even though we aren't discussing them) 7260 U-joint..

Was the cone SG junk?

 

[Darter6]

Actually no.Wore out was a poor choice of words. Too much friction modifier.I did a axle change,used gear oil that had modifier in it and added 2 more bottles.You know,it was a "What was I thinking?"moment. Surely not for a drag only car.

 

[Cranky]

Actually no.Wore out was a poor choice of words. Too much friction modifier.I did a axle change,used gear oil that had modifier in it and added 2 more bottles.You know,it was a "What was I thinking?"moment. Surely not for a drag only car.

What did it do....slip?

 

[Darter6]

Yes, For lack of a better choice of words I could feel it "walk" as it went down the track.I was also told by a observer that the wheel spin during burn out was un-even with the same "walk''. I hope you get my meaning. Not sure how to put it.