• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

741 Case Worth Making Sure Grip?

twodxtream

Active Member
Local time
1:15 PM
Joined
Oct 6, 2011
Messages
30
Reaction score
2
Location
diamond bar
I have a 66 charger with a 2.94 open. Looking for a center section with Sure Grip (3.55 or 3.73). Hard to find in So Cal. Is it worth it for me to convert my 741 case into a sure grip? I know the 742 and 489 are prefered but its just a cruiser. Power is a 360 with 410hp & 440tq.

:sFl_america2:
 
It'll work....but, how many 41 case rears have you seen broken? I've never seen any either :)
 
I think you will be fine just putting a auburn cone type limited slip it will give you 2 black marks on the road quiet operation unless your putting slicks on I doubt you will break it. I have the same setup in my Challenger with 383 and a hard shifting trans no leaks no complaints no noise. Since your not changing pinion putting one in yourself is actually fairly easy with minimal tool purchase and a FSM. Mopar action did a arrival on this a while back wouldn't hurt to scare up a copy.
 
That 741 will work just fine, but try to get a clutch style sure grip, they are stronger and easier to rebuild at home since they use clutches. eBay has them for 385 with free shipping and are new units.
 
i ran a 12 second 1970 Dart with slicks on a 741 using a 3.55 gear , trouble is gear choices are limited , watch out for those chineese sure grips - i think you end up having to get out a grinder to fit into the carrier.

actually for my Charger i just picked up a complete 3.91 geared ,clutch type sure grip , 741 center section date coded for 1965. this was a factory piece -
 
I have a 66 charger with a 2.94 open. Looking for a center section with Sure Grip (3.55 or 3.73). Hard to find in So Cal. Is it worth it for me to convert my 741 case into a sure grip? I know the 742 and 489 are prefered but its just a cruiser. Power is a 360 with 410hp & 440tq.

:sFl_america2:
if your not planning on huge horse power and hooking up...741 is excellent. I have one in My 67 r/t...solid as a rock and does excellent burnouts.
 
The sure grip is being sold by Dr. Diff, I'm sure Cass wouldn't sell junk.
 
741 is fine. It may be the smallest mopar center but it's still pretty beefy. I'd have no qualms about running one. I think you'll need the thrust buttons between the axle shafts. I'd also swap to a dana style yoke.
 
For the ones that talk about hooking up with slicks etc...what have y'all seen broken on them. When I was building rear ends, I always sold the 42's and the 89's and kept the 41's for myself since everyone said they were junk and didn't want to cough up any coin for them. I hammered them. Check out this link....and it's by Dr Diff himself. Don't know how long he's been at it but I knew that the 41 wasn't a weakling by any means and bought them for little of nothing.

http://www.moparts.org/Tech/Archive/axle/1.html
 
Didn't the max wedges use the 741?
pretty sure everything with a 361 and up used a '742 or '489. there's a reason for this or the factory wouldn't have spent the time or money to tool up or stock two different gear sets plus bearings. i'm not a rear gear expert but if you look at this stuff you start to notice larger inner pinion bearings for higher torque engines. the inner pinion timken bearing controls the thrust during a high load. the way the helix is cut into the gear teeth causes the pinion to be thrust toward the front. the bearing controls the thrust which keeps the pinion head located. i have a couple of '741's with 2.94 gears and thought about using them behind my 440's for road gears. i'm sure they would drive fine but when i look at that large diameter pinion gear head and small diameter bearing i decided this isn't something i want to hammer on. i think the smaller the pinion gear head is the safer they would be for beating on. i think they would be more suited for a lighter a-body/a-engine combo for performance use. just my 2 cents.
 
For the ones that talk about hooking up with slicks etc...what have y'all seen broken on them. When I was building rear ends, I always sold the 42's and the 89's and kept the 41's for myself since everyone said they were junk and didn't want to cough up any coin for them. I hammered them. Check out this link....and it's by Dr Diff himself. Don't know how long he's been at it but I knew that the 41 wasn't a weakling by any means and bought them for little of nothing.



http://www.moparts.org/Tech/Archive/axle/1.html

Thanks for the link, Cranky!

Three quotes directly from Dr. Diff in the link Cranky provided:
- "Notice, all pinion shafts neck down to the same diameter at the front bearing area."
- "Notice, the popular Ford 9" uses the smallest pinion shaft of the bunch. "
- "As you can probably tell from this post, I consider the 741 case 8 3/4" to be highly underrated when compared to other more popular "performance" ring and pinion designs."

Cranky, I'll bet you have also been putting peanuts in your Coke and listening to country music long before it was cool! :headbang:
 
I think he's been around since before rocks were hard!
 
Cranky, I'll bet you have also been putting peanuts in your Coke and listening to country music long before it was cool! :headbang:
Well....I do like some country music and like peanuts too but I quit drinking Coke many moons ago. The only soft drink that I down anymore is Barq's Root Beer when I go get a hamburger or pizza. :hello2:
 
one of the main problems with the 489 and the 741 is it uses a crush sleeve witch is a weak point in the pinion under high loads burnouts / hooking / high cornering loads . the 741 case is built stronger than the 12 bolt chevy/ ford 9in. 742/489 even stronger . randys ring and pinion has a solid insert simular to the 742 witch will strengthen 489 741 eliminating crush sleeve . the real weak points to the 8 3/4 is the housing (it flexes)and the axles yolk straps ring gear thickness . it can be back braced too then you start having main cap shift in all the rears but they will take a beating, when you do beat them uo you have to check them out periodically . thats why most every one wants or has a dana 60 .costs almost the same to beef up a 8 3/4
 
one of the main problems with the 489 and the 741 is it uses a crush sleeve witch is a weak point in the pinion under high loads burnouts / hooking / high cornering loads . the 741 case is built stronger than the 12 bolt chevy/ ford 9in. 742/489 even stronger . randys ring and pinion has a solid insert simular to the 742 witch will strengthen 489 741 eliminating crush sleeve . the real weak points to the 8 3/4 is the housing (it flexes)and the axles yolk straps ring gear thickness . it can be back braced too then you start having main cap shift in all the rears but they will take a beating, when you do beat them uo you have to check them out periodically . thats why most every one wants or has a dana 60 .costs almost the same to beef up a 8 3/4
The 89 case is the only one that uses a crush sleeve....but the spacer on the 41 is removable and some think it's a crush sleeve. On the 42, the spacer was incorporated into the pinion shaft and does not remove.
 
i have 2 741 cases with crush sleves

- - - Updated - - -

i have 2 741 cases with crush sleeves when i rebuilt them the kit came with a crush sleeve simular to the 489.i have rebuilt and replaced pinions in 742 and used the thrust spacer and shimmed it with a kit . so i dont understand what you wrote but mabe there are different parts for different years
 
Well....I do like some country music and like peanuts too but I quit drinking Coke many moons ago. The only soft drink that I down anymore is Barq's Root Beer when I go get a hamburger or pizza. :hello2:

Guys, listen to Cranky. Nothing goes better with pizza than an ice cold root beer. :icon_jook:
 
i have 2 741 cases with crush sleves

- - - Updated - - -

i have 2 741 cases with crush sleeves when i rebuilt them the kit came with a crush sleeve simular to the 489.i have rebuilt and replaced pinions in 742 and used the thrust spacer and shimmed it with a kit . so i dont understand what you wrote but mabe there are different parts for different years
Well, I don't pretend to know everything there is to know about the 8 3/4 but in the 31 years I've been working on them, I've never found a crush sleeve in a 41 case unit....just a spacer that's about 3" long that goes between the front and rear bearings and generally they come with just one shim between it and the front bearing. I never ordered a kit to rebuild any 41's because to me, they are not worth it and most that I got were in good condition but took them apart just to check out. If they looked good, I plugged it into one of my cars if I needed to. Generally, they were 2.94 or 2.76 and I used those for my highway cars. If a kit came with a crush sleeve for the 41, I wouldn't use it anyways. One of the things I do with the 89 is to file 13 the factory crush sleeve and install a solid spacer and set it up like the 41 and 42's. Now the 9 1/4 comes with a spacer/crush sleeve that's very short and very difficult to crush...unlike the 89. The crush sleeve setup was just another way for the factory to save some money in setup costs.
 
Auto Transport Service
Back
Top