Author Topic: Another �Is it a peg-leg or a Sure-Grip� Question (Read 3988 times)

RB2929 · « **on:** September 14, 2011 - 08:23:58 PM »

Hi All-
Yes, another �Is it a peg-leg or a Sure-Grip� question.
When the rear-end was assembled, I remember turning one wheel and the other did not turn. Thus, I assumed that the B�Cuda has a peg-leg third member. While doing the unscientific research, we came up with a gear ratio of 2.71ish:1. It makes sense since the car was born as a 318 with a 904 Slap Stick.
Also, it�s a Frankenfish - I think the previous owner who had a field full of E Bodies slapped this one together for selling purposes.

I have a friend that has a bunch of Mopar cars and races A Body Cudas. Talking with him about my gearing issue, he said that he has a handful of different ratios that I can choose from.

So, over the weekend my other buddy and I pulled out the third member. Along the way, I noticed a few peculiarities. The drive shaft was rather shinny and no rust to speak of. Thinking that it may be aluminum, I placed a magnet against it � but the magnet stuck. Being magnetic also rules out stainless steel (right?). So, there�s still a bit of a mystery.

Getting the differential out was rather easy, just a little heavy. It�s a 489 case with the smaller U-joints.
Turning the coupler where the drive shaft would attach, I noticed that both of the axle input shafts turned. Looking in my official Chrysler manual under the Sure-Grip section, I noticed that the picture and Diff looked very similar. They both have a square cut out were you can see heavy springs.

Also, the Diff has a factory installed pinion snubber. Wouldn�t think that would be installed on a non-Sure-Grip.

My buddy, a Chevy person, was unable to help other than suggesting that it may be a Sure-Grip unit but maybe something broken; that�s why the tires didn�t turn simultaneously (or, maybe, too many Coronas that day).

So, I�m asking ya�ll to please provide your expertise opinions.
1. What could the drive shaft be made out of?
2. Could the Diff be a Sure-Grip?
3. While it�s out of the car, are there any tests to determine Sure-Grip or Non?
Thanks ahead of time for your assistance
Ron

72rtchallenger · « **Reply #1 on:** September 14, 2011 - 08:39:47 PM »

looks like a sure grip,Non-Sure Grip differentials can be identified by the large openings in the differential exposing the differential (aka. spider) gears. There are no springs or clutches. try this link
http://www.moparfins.com/Repairs/8-3-4_Rebuilding/Information_on_Mopar_Rears.htm

ChallengerHK · « **Reply #2 on:** September 14, 2011 - 08:51:52 PM »

My 318/904/2.76 car came with a factory pinion snubber.

Cooter · « **Reply #3 on:** September 14, 2011 - 08:59:02 PM »

Looks to be the "Cone load" style Sure Grip used from 1968or9 through '74 IIRC...

1970 RT Challenger 1970 · « **Reply #4 on:** September 14, 2011 - 09:03:02 PM »

the_engineers · « **Reply #5 on:** September 14, 2011 - 10:51:59 PM »

May be worn out...if the clutches won't engage, that could be why it's only spinning one tire. I don't think the cone-style can be rebuild, but I'm not 100 %.

Find some gravel...your 318/2.76 isn't exactly a tire-burner anyway...

Chryco Psycho · « **Reply #6 on:** September 15, 2011 - 12:29:11 AM »

Definatly a cone sure grip diff
once the cones wear out the cone bottom in the case & lose their grip , you can do a bandaid fix & machine the end of the cone off & shim upo the spring to get a few more miles out if it.
the gear ratio will be stamped into the edge of the ring gear

RB2929 · « **Reply #7 on:** September 15, 2011 - 08:08:54 AM »

Good morning All-
Thank you very much for the quick responses.
I�m rather surprised that it�s a Sure Grip, but not surprised that it�s worn-out.

72 RT Challenger-
Thank you for the link. I�ll give it a good reading this morning.

The_Engineers,
Sorry, but the Diff is out of the car. Can�t play on gravel roads .
�your 318/2.76 isn't exactly a tire-burner anyway...�
- That, Sir, is an understatement.
My previous Cudas and other Mopar cars* all had higher gear ratios and would leave tire marks.
*My 1982 Chrysler K-Car, with the 2.2L wouldn�t burn the tires.

Cooter,
Thank you for the history info. What�s an �IIRC�?
- I know, more questions.

Chryco,
Thank you for the helpful hint that the gear ratio will be stamped into the edge of the ring gear.
I don�t want a band-aid fix; my back doesn�t care too much to crawl under the car, or standing up afterwards.

Looking at Summit Racing, there�s rebuild kits along with different gear ratios to choose from.
I�m partial to 3.55s, but, the Cuda will be used for red light racing, not highway use, so the 3.73 are also an option.
All that being said, I won�t be the one rebuilding the unit. I know: Good luck finding a local shop that can work on something rather than Chevy.

Second option, I have a Mopar friend that has a handful of Diffs to choose from. I saw them, they were piled up on a wooden shelf in his work shop.
The Diffs are still covered with the road grime from the day they were removed. I guess the problem with this option is that you can�t tell if the unit is operational or not.
When I asked him about the condition, he said those magical words: They worked when I removed them.
- If you have advice on how to tell if a unit is operational with it sitting on a shelf, please speak up.

Again, Thank you ALL!

I have some decisions to make.
I�m going to visit my friend with the multitude of Diffs and take a serious look at what he has to offer.
Maybe I can borrow one and test it on my car.

If ya�ll have more words of wisdom, please post the.
I learn a lot from this site � thank you for sharing your wealth of knowledge and experience.

Ron

the_engineers · « **Reply #8 on:** September 15, 2011 - 11:12:14 AM »

IIRC = if I recall correctly

Chryco Psycho · « **Reply #9 on:** September 15, 2011 - 11:17:17 AM »

Doctor diff can build you a new complete Carrier for $1100 or so with the gear ratio you want

Cooter · « **Reply #10 on:** September 15, 2011 - 12:10:32 PM »

Quote from: RB2929 on September 15, 2011 - 08:08:54 AM

Cooter,
Thank you for the history info. What�s an �IIRC�?
- I know, more questions.

Ron

IF I Remember Correctly...

RB2929 · « **Reply #11 on:** September 21, 2011 - 07:24:22 PM »

Hi All-
Has anyone done any business with MOPARTS Parts & Supplies?
Link: http://marketplaceadvisor.channeladvisor.com/StoreFrontProfiles/deluxepagecreate.aspx?sfid=92390&type=e3

I have a local mechanic that will rebuild/upgrade my differential.
He�s a Ford guy and has rebuilt multiple Ford 9 Inchers and a couple of 8.75 Mopars.

I�m looking at MOPARTS to purchase the ring & pinion set, along with the install kit, and, more importantly, the other components to freshen up he sure grip.
Looking at the other differential web sites & Summit, but they don�t carry the clutch replacement kits.

Chryco-
Sorry, but I don�t see mailing the 80LB diff to Dr Diff. Maybe if I didn�t have a choice, but my local guy comes with positive recommendations.
And, he�s local. No need to crate up the unit.

Thanks All,
Ron

Author Topic: Another �Is it a peg-leg or a Sure-Grip� Question (Read 3988 times)

RB2929

Another �Is it a peg-leg or a Sure-Grip� Question

72rtchallenger

Re: Another �Is it a peg-leg or a Sure-Grip� Question

ChallengerHK

Re: Another �Is it a peg-leg or a Sure-Grip� Question

Cooter

Re: Another �Is it a peg-leg or a Sure-Grip� Question

1970 RT Challenger 1970

Re: Another �Is it a peg-leg or a Sure-Grip� Question

the_engineers

Re: Another �Is it a peg-leg or a Sure-Grip� Question

Chryco Psycho

Re: Another �Is it a peg-leg or a Sure-Grip� Question

RB2929

Re: Another �Is it a peg-leg or a Sure-Grip� Question

the_engineers

Re: Another �Is it a peg-leg or a Sure-Grip� Question

Chryco Psycho

Re: Another �Is it a peg-leg or a Sure-Grip� Question

Cooter

Re: Another �Is it a peg-leg or a Sure-Grip� Question

RB2929

Re: Another �Is it a peg-leg or a Sure-Grip� Question