The 8 1/4 thread

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halifaxhops

It's going to get stupid around here!
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@memike and myself decided to start a thread all about 8 1/4 rears and common problems. Lets start with carriers and housings. The housings are two different distinct easy to identify The first is the most common with the pinion centered for 2.57 ratio and down the other is the off center pinion carrier for 2.56 gears and up. see how the pinion is off centered.

Here is the 2.56 and up carrier.
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Here is the most common housing. See the pinion is almost center.
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There is a reason for this and here it is.


The pinion on the left is a 2.45 the one on the right 3.23 So the pinion has to be offset to run those gears.
 
But wait folks there is more, The carriers are different also. the one on the left is from a 3.23 rear and the one on the right is a 2.45 carrier. You can see the high ratio carrier flange for the ring is shifted back by almost half an inch so they are only able to fit into the respective carrier. We will up date this as the information goes on. Do not be afraid to add any information for the 8 /14 rears here.

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Another difference with some carriers are the carrier bearings, there are to different sizes one is 3.2?inch and the other is 2.8? inch. There was supposedly a year break in the 70's I believe 72 they went to the larger bearings but my 74 has the 2.8 ones.
 
So, if the housings are different, can you pull out a 2.45 carrier and install a 3.55 carrier? If the 2.45 housing is different offset, then I would think this would be impossible, but some have installed 3.55's from a Dakota inplace of their 2.45's.
 
Most of my gears come from Dakotas (Dana 30) You talking about the other way in a dana 30 no idea I would have to look at a housing to see. Yes it is impossible to do that now a carrier from the 245 going the other way you would need a spacer around 1/2 inch. MEMIKE is going through this right now and is just going to get the right carrier, I have no idea if a spacer would stand up to the forces, plus where would you find left hand bolts that long and strong?
 
I think I remember a set of 2.45 from a dana and the ring was pretty small in thickness and the pinion was huge.
 
little confused by what you've said. If somebody has a Duster with the 8 1/4 with factory 2.45's, can he put a 3.55 gear and carrier together from a '94 Dakota into the housing (in the Duster)?
 
Probably has the off set carrier if it is 2.45 What I was trying to share was the carrier from a 2.45 is offset to one side and it prob could be used in a lower carrier with the center pinion if they had a spacer made up. Still confused? It is hard to explain. Look at the carrier pics for the offset. I do know for a fact the dana 30 carrier and gears will fit in a centered housing not the offset one. One of our members is going through the high ratio carrier will not fit in the lower carrier.
 
I see the pictures, and understand the difference in carriers. What I'm asking is, can someone pull the factory 2.45 carrier out of their Duster and install the 3.55 carrier into the duster's housing?
 
Not if it has the offset pinion the gears will not line up. Have to look at the carrier to be sure it is offset. It should be offset then no, if it is centered yes.
 
i just installed a newer ( with reluctor ring) posi carrier with 3.55 gears in place of the open 2.45 carrier in my ( 8.25 that came out of a 1974 dart) car. The carrier and pinion bearing sizes were different on each carrier but i just ordered new bearings to fit the 74 factory carrier and they fit right on the newer carrier and went right in with no issues. pinion was same inside and outside diameter on both pinions but bought new bearing anyway.

I have read where some people remove or grind down the teeth on the ring because it hits inside of the case. Mine did not hit so left it alone
 
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So you were able to off set it? How just bearings? I am defiantly interested in this. That's why this thread is here.
 
Hope this helps.

I've done this a few times, and what I found is that there are 2 different sure grip carriers.

One of the carriers will fit the 2:45 gearsets and lower numerically, and will not fit 3:55s

You'll need a suregrip carrier that came with a 2:76 or higher numerically to fit the 3:55's etc.

If the 3:55s come with a sure-grip from a vehicle, it'll fit if the axle splines are correct. (It is possible to mount the 3:55 on the wrong carrier, buyer beware.)

Bearing sizes, axle splines vary as mentioned above.

The reluctor ring is separate and can be left out.
 
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so basically i bought that carrier/pinion ring gear setup. the carrier bearings that came with the new carrier were to big outside diameter but inside diameter was the same size as the ones on the old carrier and pinion bearing was the same inside and outside diameter but got new bearing as well.

So i bought new factory type/size bearings for the old carrier and installed them on the new carrier and did new axle seals and bearings as well.
 
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I knew there were two different carrier, I need to post the bearing and race numbers of the two sizes since I have them around right now.
 
I have not seen a difference in offset in the housings, only the carriers. My 75 Dart had the 2.45 gear set before I changed out the gear set and carrier to a sure grip from a Dakota. Still the same housing.
 
There definitely was good info in both the threads for sure. I believe what we are trying to do with this one is to eliminate some of the issues of the 8 1/4 gear and carrier swap.
 
I have not seen a difference in offset in the housings, only the carriers. My 75 Dart had the 2.45 gear set before I changed out the gear set and carrier to a sure grip from a Dakota. Still the same housing.

Kind of weird it fit I would love to see pics if you took them. Was the carrier offset compared to the others toward the left side installed?

In the beginning of this I took some pics and the "offset" carrier is the one not in the car.
 
Actually I have never heard of different offset housings, only the carrier. It is just like the spacer for the Chevy rears where you shim out the ring gear instead of changing carriers. They used to make the spacer kit for the 8.25 and Dana I believe which also came with longer special bolts. The issue with using Dakota carriers is mid 96 and up have different spline count and some need different carrier bearings.
 
Kind of weird it fit I would love to see pics if you took them. Was the carrier offset compared to the others toward the left side installed?

In the beginning of this I took some pics and the "offset" carrier is the one not in the car.
I did take pics but they may be lost in Myspace somewhere.... There is definitely a difference in the 3.55 and 2.45 carriers but if the gears are matched with the correct carrier you should be good to go. I used the same shims from the 2.45 pinion and it set up fine with the 3.55.
 
Actually I have never heard of different offset housings, only the carrier. It is just like the spacer for the Chevy rears where you shim out the ring gear instead of changing carriers. They used to make the spacer kit for the 8.25 and Dana I believe which also came with longer special bolts. The issue with using Dakota carriers is mid 96 and up have different spline count and some need different carrier bearings.

There was different "posi" carriers for the chebby, for the taller gearset, and a M/Mouse "spacer" as mentioned. The spacer didn't prove to be too succesful, as spacing the ring-gear out took the ring-gear off it's register. Not having anything to "center" the ring-gear on except the bolts, allowed the ring-gear to wander, and eventually sheared/broke the bolts, damaging the gears.

I can't speak to any of the other "kits" avail.. specially for hipo stuff.
 
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