Sure Grip Advice

[domdart]

While driving home from Carlisle, I noticed the whine from the rear end has got worse. It whines on acceleration. It is a 741 case 3.55 cone style that I bought here on FABO. I have the original open 3.23 741 from a 72 Duster 340. I want to go to 3.23 sure grip. Would you buy a sure grip for the open 3.23 and sell the 3.55, or buy a new gear set for the 3.55? Another option would be to switch parts from the two diffs. What would you do? Thanks FABO.

 

[George Jets]

Your main Carrier bearings on the 3.55 gear set are probably wearing enough to allow the ring gear to start moving away from the pinion changing the Pinion to Ring gear wear pattern creating the whine.

You should be able to take your Cone Style Sure-Grip from the 3.55s and swap that over to the 741 with the Open 3.23 gear set. Along with a new bearing set and setup. Cone style Sure-Grips have 2 spider gears and the cones can wear out. The Clutch Style Sure-Grips have 4 spider gears making them much stronger and less slop in the differential as a result. Less "Clunking" when you drop into gear.

 

[RustyRatRod]

I would adjust the pinion depth on the 3.55 and stop the noise.

 

[65 Cuda 340]

Not any kind of expert on rear ends, but the 3.23 gears that used to be in my 67 Barracuda whined for years, finally took it to someone figuring it would need new ring and pinion, turned out it was the carrier bearings. Gears were fine.

 

[413]

Sell the 3.55 Whole
Buy a new SG to go into the 3.23

 

[Demonic]

Spartan Locker. I listened to mine click all weekend.

 

[AJ/FormS]

What would you do? Thanks FABO.

Because I am able to do all my own work on these; I would rebuild and swap the SG over to the 3.23s and sell the 3.55s as a used R&P set, without the case .. for the following reasons;
1) everybody wants the 3.55s and
2) nobody wants to pay the shipping on the 741 case
3) half of everybody already has a good-working SG and
4) nobody wants to take a chance on the life of the cone-type, altho they are pretty easy to rebuild.
>That's what I would do, if I had a Cone-Type, and an automatic trans.
>But if I had a 4-speed, I would leave the 3.55s in it; and shelf the 3.23s.
>If I had a Clutch type SG and 3.55s and an automatic trans, I would sell that whole set-up in a heartbeat cuz that is the premiere set-up and worth Gold, lol. Then I would score a worn-out Cone-type for near-zero dollars, rebuild it for pocket-change, and put it all back together with the 3.23s; then with all the money I made, I would go get me a hi-stall convertor.
That's what I would do.

 

[MOPAROFFICIAL]

While driving home from Carlisle, I noticed the whine from the rear end has got worse. It whines on acceleration. It is a 741 case 3.55 cone style that I bought here on FABO. I have the original open 3.23 741 from a 72 Duster 340. I want to go to 3.23 sure grip. Would you buy a sure grip for the open 3.23 and sell the 3.55, or buy a new gear set for the 3.55? Another option would be to switch parts from the two diffs. What would you do? Thanks FABO.

I would go with new bearings on the 3.55.
If money is no object and you want 3.23...then buy a new sure grip and bearing set for it. 741 is strong enough.

 

[Bewy]

Agree with others, the whine is likely caused by worn brgs allowing the ring & pinion depth/engagement to change. I would take it to an expert for repair unless you are experienced at re-building rear ends.

 

[domdart]

I bought the new sure-trac II from Cass. I'll put that into the 3.23 then take out the 3.55 and see if I can figure out why it whines. When you bolt the ring gear to the carrier do you put the bolts in all oily like when they come out? Does blue locktite work on oily bolts?

 

[Sterling]

The threads of the ring gear bolts are probably not oily, but I would clean them and use red loctite, and torque the bolts to spec. Should be left handed thread bolts. And you will have to reset the backlash .

 

[domdart]

I put the sure-trac II in today. It took a while to get the backlash right. It is .008. The hardest part was getting the ring gear on the carrier. Here is a pic of the gear test.

 

[my68barracuda]

What are you using to be able to see the gear contact pattern?
What you need to use is yellow gear marking paste.

 

[RustyRatRod]

What are you using to be able to see the gear contact pattern?
What you need to use is yellow gear marking paste.

Looks like mayonnaise.

 

[RustyRatRod]

I put the sure-trac II in today. It took a while to get the backlash right. It is .008. The hardest part was getting the ring gear on the carrier. Here is a pic of the gear test.View attachment 1715959490

It's a huge help to heat the ring gear in an oven. Gives you a little time to slip it on and line it up good.

 

[Sterling]

If you did not disturb the pinion, and the backlash is correct, the pattern should be the same as it was.

 

[domdart]

It's a huge help to heat the ring gear in an oven. Gives you a little time to slip it on and line it up good.

That's a great tip. I will try that the next time.

 

[domdart]

I used white lithium grease. I couldn't find the yellow stuff at any of the local stores.

 

[my68barracuda]

I used white lithium grease. I couldn't find the yellow stuff at any of the local stores.

the lithium grease is not working for you

 

[RustyRatRod]

I used white lithium grease. I couldn't find the yellow stuff at any of the local stores.

I thought it was Hellmans. LOL

 

[my68barracuda]

I thought it was Hellmans. LOL

No, Hellmans has a light yellow tint, looks like Kraft Miracle Whip. It’s much more white in color.

 

[Bodyperson]

I think mayo would work just fine. Just not so much of it.

 

[domdart]

I put in the sure-grip 3.23 and went for a ride. There is no whining or humming, it goes 70 mph @ 3100. Glad I made the change. The 3.55 was very tight, almost no backlash. I moved the carrier one notch on the adjusters. I checked the gear mesh and it seems fine. Tomorrow I'll check the carrier bearings, see if I can see anything wrong with them.