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741 differential.

Russ69Runner

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Well I had rebuilt the carrier in this 741 differential. Pinon and Ring gear. All new bearings'. So have it mounted under the car and grabbed the input yoke to turn it and heard that not so good sound of the clunk. So it has to be the worn spider gear's in the carrier. I spent all day yesterday looking and calling around. Every thing for the Dana or the mopar limited slip but nothing for the opened gear. If any one has an idea where to get these gear set would appreciate the info. Someone told me that they made the limited slip carrier to go into the 741 but thought that we had discussed it would not work. Well hope someone know some place to get the part's Russ. :(
 

roadrunninMark

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Any of the modern 8 3/4 (741,742,489) limited slip units interchange into each other. The gears do not.
 

Rich B

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Agree with RRM, have made that swap myself. Used to call that complete assy. “the pig”. Just use rear drums in reverse and lightly nutted as gear pullers to pop out rear axles. As I recall those rear wheel bearings are sealed; not lubed with differential oil (yup, go bad).

Easy enough for experiment gear ratios. Make sure the nut is secure for rear pinion drive shaft bolt connection.
 

droptop

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At this point, I think you would be better off getting the correct 489 unit. Also if I am thinking correctly, the 741 has the small yoke for the u joint, so you will have to have a custom made drive shaft as well.
 

Russ69Runner

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Doctor diff sold me a new yoke for the rear end with a mix matched universal joint. That fixed the problem with the new yoke to the drive shaft. Going to call Randy's tomorrow and see if he has the Washers that go behind the drive gear's and the spider gear's. They did not look that bad not broken but must have some wear on them. Your right on about a different rear end If I have to go that far will swap out for a Dana at a later date. Just want to get the car finished. Some one is telling me that I can put a limited slip carrier in this one. Will see what that is all about. The 741 has the smallest pinion shaft and is only 10 spline which make's it a weaker one than the 489 or the 742. Also see an up graded chunk housing that will fit the 741 differential. Well might get some good result's on Monday. I was calling around on Friday the 13 and every thing kept coming back no no and no. Hope m
 

droptop

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The 2 sized u joint is junk. Twisted one completely in to. That will be the weakest link in your drivetrain.
 

Russ69Runner

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I know your rite on that. But for now if it will get it down the road I will be happy. All this can be changed after the car is done. Will opt to get a Dana look's like you can get all the part's for it still. If you twisted it off you must have really been getting down on it. That universal joint. Droptop. :thumbsup2:
 
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Rich B

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Not sure if they ever came through with a true positraction differential. Mine was limited slip or not, never saw 2 full black stripes on tar with launches.
 

ACME A12

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Not sure if they ever came through with a true positraction differential.

They didn't. That's the Chevy/GMC name. MoPars came with Sure Grip Differentials. All just different names for a limited slip differential... List of LSDs courtesy Wikipedia...



Alfa Romeo: Q4, Q2

Audi: Quattro, Quattro with Sport Differential (rear axle)

American Motors: Twin-Grip

Buick: Positive Traction. Gran Sport models used the term "Limited-slip (differential)"

Cadillac: Controlled

Chevrolet/GMC: Positraction

Chrysler: Sure Grip

Dana Holding Corporation:Trak-Lok or Powr-Lok

Ferrari: E-Diff

Fiat, Lancia: Viscodrive

Ford: Equa-Lock and Traction-Lok

Hyundai: HTRAC

International: Trak-Lok (clutches only) or Power-Lok (clutch and ramping engagement process)

Jeep: Trac-Lok (clutch-type mechanical), Tru-Lok (gear-type mechanical), and Vari-Lok (gerotor pump), Power Lok

Lincoln: Directed Power

Maserati: Equ-Tor

Nissan: GT LSD

Oldsmobile: Anti-Spin

Pontiac: Safe-T-Track

Porsche: PSD (electro-hydraulic mechanical), Porsche Torque Vectoring/Plus (PTV/Plus, combined electro-hydraulic mechanical and brake-based type; rear axle only)

Saab: Saab XWD eLSD

Studebaker-Packard Corporation: Twin Traction

Toyota: LSD

TVR: Hydratrak

Yukon Gear & Axle: Duragrip

Mercedes: ASD, AMG Rear-Axle Differential Lock (active differential on select FR-based AMG/S models; pure mechanical variant also present on select non-S AMG models)
 

Russ69Runner

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Ok so here is the latest idea. See that Auburn makes a limited slip differential for the 741. Has any one have info on these. I call Summit and they are telling me that all my new ring gear pinion and bearing's will swap over to this carrier. The one he described and gave me a number for will work in the 741 rear end. So does any one have any different info on if this is true. Hoping that the axle's and all will fit rite up and will be an easy swap out. Russ.
 

droptop

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Why are you hung up on the 741? You are going to have as much in the smaller pinion than you would in a big pinion. You say you are going to upgrade later on anyway. Why not do it right the first time so you don’t have to do it again. :2cents:
 

Russ69Runner

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It is painted-hung in place and ready to roll. Have new Drum's-Brake lines. Not mention new ring gear and pinion. Lot of money to stop and change it all right now. So if you invested that much money would you not try to fix it enough to roll with it for a while. Also have Tire's and rim's on it. Want to finish it and drive it for a while. At that point I could get the other rear end and prep it paint it and get all the hard ware I will need to install it. That all take time as you know. I am still painting body part's and have so much to do to finish it. Don't have time to change putting the body and every thing else together. I think it make more sense to finish the car for now. Thanks for your thought's if it was a finished car and this is all I had to do then I would under stand. Russ.
 

Rich B

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For sure, do one choir a day. Nothing overwhelming but enough to show progress. If you attempt any more, nothing gets done. At least seems to be that way now a days for me.

Too, be sure as you change assembly as whole. Those must be preloaded/stressed with various shims installed. Have never done just gears, not certain if I could ever get right.
 

69hemibeep

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Russ the only thing you change is the center section your housing and brakes stay.
 

Russ69Runner

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Thanks Bob. I have my eye on one rite now. I called a couple of places on a 742 and had to brake out the hart attack pill's. I will look around and find one I can rebuild my self. Looking to get the sure grip. Or if I can find one with the dana. Thanks guy's. The car will probably start out with the 741 and have to put up with the clunk. I did not like the crush sleeve in the 489 and not having a Hemi don't think will need any thing that big. Russ. :thumbsup2:
 

dmartin

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R
It is painted-hung in place and ready to roll. Have new Drum's-Brake lines. Not mention new ring gear and pinion. Lot of money to stop and change it all right now. So if you invested that much money would you not try to fix it enough to roll with it for a while. Also have Tire's and rim's on it. Want to finish it and drive it for a while. At that point I could get the other rear end and prep it paint it and get all the hard ware I will need to install it. That all take time as you know. I am still painting body part's and have so much to do to finish it. Don't have time to change putting the body and every thing else together. I think it make more sense to finish the car for now. Thanks for your thought's if it was a finished car and this is all I had to do then I would under stand. Russ don’t forget the crush sleeve
 

Russ69Runner

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Yep D I know. After much research Figure on going with the 742 sure grip. Looking for one to rebuild my self. Called a couple of places and they think they are gold. I can rebuild it my self if I can get all the part's. With the sure grip that get's rid of the spider gear's you cant find. Russ.
 
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