Rear gear set

[khryslerkid]

This sounds interesting. I'm totally clueless when it comes to sure grip. I've never owned a car that wasn't open carrier so not sure what exactly I would need to purchase to convert. Here's what I see.

Power-lok clutch type sure grip - $395
3.23 or 3.55 ring and pinion. $185. (I only see Dr. Diff/Hooser brand for 3.23, and Motive/Richmond for the 3.55)

So I'm already in well over 500 and don't have all that I need.

Dr Diff does have the 3:23 ring and pinion, Nitro brand. I don't believe it's listed. I'm thinking he had the 3:55 also in the Nitro brand. Talking with him this is what he recommended for the ease of setting them up and they weren't known to be noisy.

Now in my situation, I had bought a used sure grip unit and after driving it for awhile it was a little noisy mainly because it was "well used". So after disassembling it, it definitely needed everything.

After the cost of the used unit plus totally replacing ring and pinion, bearings, new clutches, I would almost have been better off to spend the money on a complete rebuilt unit from Dr. Diff. That's the way it added up for me.

 

[Coronet67guy]

Think there's a 742 sure grip on eBay for $300. You'd need a new case tho.

Yes. My issue exactly. I want to stay with the 489 case and finding the right sure grip without it costing an arm and a leg is hard. I might leave that for the next guy who doesn't like my gear selection. lol

 

[vintage chromoly]

Motive used to be made in Italy.
Now Korea.
I paid a hundred extra for Dana spicer gears made in the USA by Americans.

I’d put a 3.55 in it, if I were you.

Agree on the Dr. Diff. Call Cass and order from him. Always spot on and great customer service.

 

[bee71]

3:23 Nitro brand much quieter.

 

[Fran Blacker]

Won't a 742 sure-grip fit a 489 because I had a power-lock in a 489. That $300 one ebay maybe fine but for $100 extra go new. No sure-grip right rear tire wear.

 

[Coronet67guy]

3:23 Nitro brand much quieter.

Having a hard time finding any Nitro brand except on their website. They seem priced right with the Yukon's.

 

[Coronet67guy]

Won't a 742 sure-grip fit a 489 because I had a power-lock in a 489. That $300 one ebay maybe fine but for $100 extra go new. No sure-grip right rear tire wear.

I was thinking the same thing. Not sure I would need a new case to use a 742 sure-grip, and if I can get a new one for $400 I wouldn't spend 300 on a used one.

 

[Cranky]

Yup, talk to Cass at Dr. Diff.....actually, don't remember anyone else answering the phone whenever I called. If it were me, I'd go with the 55's. Have you thought about just using a larger tire if you need to take a long highway run? Also, I have a Detroit Locker that was removed shortly after installing it because the guy's wife didn't like the sound it makes when turning. That thing was 539 bucks from Summit back in Sept of 2012!

 

[Coronet67guy]

Yup, talk to Cass at Dr. Diff.....actually, don't remember anyone else answering the phone whenever I called. If it were me, I'd go with the 55's. Have you thought about just using a larger tire if you need to take a long highway run? Also, I have a Detroit Locker that was removed shortly after installing it because the guy's wife didn't like the sound it makes when turning. That thing was 539 bucks from Summit back in Sept of 2012!

Not a bad idea at all on the tires. Doing some checking right now the most I could do on the stock 14 inch wheels is a 215/75R14 that gets me from a current 26.1 inch diameter to 26.7 inches. Add about $100 bucks to that locker today. I like the idea of calling Dr. Diff and explaining my set up to Cass and seeing what they recommend.

 

[Cranky]

Well, a pair of 15" steelies would open up the choices more and would mainly be for long runs. I just pulled a pair of 265-75's off of a 1st gen Dakota with 3.55's. They would work well if there was a 4.56 in that pig of a V6 but going to a tire that's 3 1/2" smaller sure made a difference. Can't believe they didn't put 3.90 gears in these things since they got an OD trans in them....

 

[Coronet67guy]

So I've been researching the different sure grip options some today. I can't find anyone that's said anything bad about the Auburn 542051. These are only slightly higher in cost than the powr-lok units on Dr. Diff that many seem to be happy with. I'm sure there are other options too I haven't looked at. Any recommended ones? Any that I should avoid? I think I might bite the bullet and do a sure grip when I change the gears. Still not sure on 3.23 or 3.55. Thanks for the input.

 

[khryslerkid]

Having a hard time finding any Nitro brand except on their website. They seem priced right with the Yukon's.

You're not reading these post. Dr. Diff sells the Nitro. My 3.23 ring and pinion was $250

You call Cass at Dr. Diff or email him. Ask him about all the other brands and he'll tell you the pros and cons. He shoots straight from the hip, no BS.

 

[john-9]

just to add to this discussion -- for those of you with a 742 case ( probably the 741 case as well ) stay away from the Yukon gear sets -- the pinion gear is not machined correctly and will not allow the pinion bearing to seat correctly into the case -- instead of undercutting the gear (same as factory gears and other aftermarket gear sets) where the pinion bearing preload shims seat ,, they left a outboard radius which distorts the shims and does not allow the bearing to seat into the race correctly.
as for the gear choice i like US Gear ring and pinions , they are made in the USA , Motive/Richmond also a good brand made in Italy --- Richmond exists in name only Motive bought them out years ago and now you get a Motive gear in a Richmond box -- good choice ( price ) for bearing kits is Ratech Manufacturing shop directly or thru Summit Racing.

 

[myk r sanchez]

So I've been researching the different sure grip options some today. I can't find anyone that's said anything bad about the Auburn 542051. These are only slightly higher in cost than the powr-lok units on Dr. Diff that many seem to be happy with. I'm sure there are other options too I haven't looked at. Any recommended ones? Any that I should avoid? I think I might bite the bullet and do a sure grip when I change the gears. Still not sure on 3.23 or 3.55. Thanks for the input.

Buy once, cry once. Might as well get it all done at the same time and get the most smiles per gallon. I bet you wont regret it no matter how much it costs.

BTW, anyone know why a differential shop would say that they can only install a 3.55 into my 8.75 (489 casing) rear? I think they said the 3.23 was unavailable, or something. But I can go on ebay and apparently follow recommendations from here and find 3.23 gears all day long. Makes no sense...

 

[Coronet67guy]

Buy once, cry once. Might as well get it all done at the same time and get the most smiles per gallon. I bet you wont regret it no matter how much it costs.

BTW, anyone know why a differential shop would say that they can only install a 3.55 into my 8.75 (489 casing) rear? I think they said the 3.23 was unavailable, or something. But I can go on ebay and apparently follow recommendations from here and find 3.23 gears all day long. Makes no sense...

That makes zero sense. I'm finding many 3.23 options along with the 3.55. Installing in the same 8.75 casing. How much are they charging you? I'll be staying out of the shop and having my mechanic who works out of his home do it. $60 an hour is much less than the shops around here and I can trust him to do it like he would do it on his own cars.

 

[Coronet67guy]

You're not reading these post. Dr. Diff sells the Nitro. My 3.23 ring and pinion was $250

You call Cass at Dr. Diff or email him. Ask him about all the other brands and he'll tell you the pros and cons. He shoots straight from the hip, no BS.

Yes I'm calling Cass today to discuss. And I've read every post.

 

[Cranky]

just to add to this discussion -- for those of you with a 742 case ( probably the 741 case as well ) stay away from the Yukon gear sets -- the pinion gear is not machined correctly and will not allow the pinion bearing to seat correctly into the case -- instead of undercutting the gear (same as factory gears and other aftermarket gear sets) where the pinion bearing preload shims seat ,, they left a outboard radius which distorts the shims and does not allow the bearing to seat into the race correctly.
as for the gear choice i like US Gear ring and pinions , they are made in the USA , Motive/Richmond also a good brand made in Italy --- Richmond exists in name only Motive bought them out years ago and now you get a Motive gear in a Richmond box -- good choice ( price ) for bearing kits is Ratech Manufacturing shop directly or thru Summit Racing.

Even if you use the factory thick shim? It usually has a pretty good radius on it. And I've used Ratech kits lots of times. In fact, they were one of the first to supply a crush sleeve eliminator spacer but the first one I got was too long so they got a call from me saying how much too long it was. Once the pinion dept was set, there was no way to get even a bit of bearing preload. Having a lathe, it was no sweat fixing the one in my hand so it didn't slow me down but they sent me a new one anyways. It took a couple of weeks so they probably did some checking and fixed the problem but at least they did it. Some companies just ignore ya.

That makes zero sense. I'm finding many 3.23 options along with the 3.55. Installing in the same 8.75 casing. How much are they charging you? I'll be staying out of the shop and having my mechanic who works out of his home do it. $60 an hour is much less than the shops around here and I can trust him to do it like he would do it on his own cars.

Rarely do I get a rear end setup that goes 100% smoothly lol so charging by the hour doesn't make sense so charging by the job is more in line. The worse one took me 8 hours to set up! Thought maybe there was a thick shim that wasn't flat or a bearing face fit that had a burr or even a bearing that wasn't right. Man, chased my tail on that one. Finally got it right but never did find anything that was the culprit....

 

[Coronet67guy]

Even if you use the factory thick shim? It usually has a pretty good radius on it. And I've used Ratech kits lots of times. In fact, they were one of the first to supply a crush sleeve eliminator spacer but the first one I got was too long so they got a call from me saying how much too long it was. Once the pinion dept was set, there was no way to get even a bit of bearing preload. Having a lathe, it was no sweat fixing the one in my hand so it didn't slow me down but they sent me a new one anyways. It took a couple of weeks so they probably did some checking and fixed the problem but at least they did it. Some companies just ignore ya.

Rarely do I get a rear end setup that goes 100% smoothly lol so charging by the hour doesn't make sense so charging by the job is more in line. The worse one took me 8 hours to set up! Thought maybe there was a thick shim that wasn't flat or a bearing face fit that had a burr or even a bearing that wasn't right. Man, chased my tail on that one. Finally got it right but never did find anything that was the culprit....

Good points. Everything he's done for me has always been by the hour, but in this situation maybe a charge to do the job would be best. Doesn't hurt to ask. Last switch I did was on a 73 charger and I had a local shop do it. Can't remember what they charged. I do remember having a leak that I had to take back and have fixed.

 

[Demonic]

Think there's a 742 sure grip on eBay for $300. You'd need a new case tho.

NO. Sure grips are not carrier dependent. They will swap between any carrier, 741, 742 or 489 as the OD of the bearing cups are the same. You're taking it all apart and getting new bearings anyway.

As far as a used Sure grip goes, it's just like a used motor, a roll of the dice. I wouldn't buy a used Auburn, but I'd buy a used clutch type and get a clutch kit.

 

[Cranky]

NO. Sure grips are not carrier dependent. They will swap between any carrier, 741, 742 or 489 as the OD of the bearing cups are the same. You're taking it all apart and getting new bearings anyway.

As far as a used Sure grip goes, it's just like a used motor, a roll of the dice. I wouldn't buy a used Auburn, but I'd buy a used clutch type and get a clutch kit.

I'll buy a used Auburn (cone type) if the seller can show pics of the internals of the unit. Even if the cones have worn to the point where the faces are hitting bottom but everything else looks good, I can fix it.