Mopar 8 3/4 or Ford 9?

[Bill Dedman]

Lemeee tell you about the axles I paid $555.00 for from Moser.

In a phone conversation, the guy at Moser told me if I wanted to buy axles from them, I HAD to take Green bearings. I didn't want Green bearings, because I have always heard that the OEM "tapered roller bearings" were superior, because of their ability to absorb lateral forces (road racing?), something that the Green ball bearings are not very good at, apparently.

Moser doesn't want to mess with OEM-type bearings... and, that's a shame.

But, I am not going to be road racing this old car, so I went ahead and ordered the A-Body axles (heavy duty) with 11/16", screw-in studs, and Green bearings.

They arrived with the following problems:

1. The flanges were not drilled for axle-retainer straight-on access for a socket on an extension, like stock axles are. I had to take them to a machine shop to get those access holes put in, at a cost of $42.00. (three holes per flange, as per the stock, OEM axles.) No, I didn't request the holes, but neither was I asked if I wanted them or not. I surely would have requested them, if I'd been asked. I think that's poor...

2. The holes in the flanges that were drilled and tapped to accept the threaded studs had a problem allowing the studs to "bottom-out" like they were supposed to; the studs had to be machined smaller at the interface of the threads and the non-threaded portion (about halfway up the stud) to allow for proper seating of the studs against the flange holes' outside periphery.

Luckily, my friend, who was helping me with the stud installation, had a lathe and was able to machine the studs so they'd thread into the flange holes, all the way.

3. This is a small thing, but the machine work (drilled holes, in particular) had no "finish" work done to it, leaving rough edges on all the holes, with machining "debris," still attached to the side of the hole-edge. My machinist friend thought that was really sloppy, and took a chamfer tool and smoothed all the edges before we installed the studs. For $555.00, I expected more...

Am I unreasonable?

 

[Badart]

I am in the process of narrowing a big bearing 9" in my tubbed dart. It's getting 4-link setup, exploder disc brakes, detroit locker and 3.89 gears. I just want it to handle power and a lot of tire down the road from a built 440.

 

[Blownfish]

1. The flanges were not drilled for axle-retainer straight-on access for a socket on an extension, like stock axles are. I had to take them to a machine shop to get those access holes put in, at a cost of $42.00. (three holes per flange, as per the stock, OEM axles.) No, I didn't request the holes, but neither was I asked if I wanted them or not. I surely would have requested them, if I'd been asked. I think that's poor...

2. The holes in the flanges that were drilled and tapped to accept the threaded studs had a problem allowing the studs to "bottom-out" like they were supposed to; the studs had to be machined smaller at the interface of the threads and the non-threaded portion (about halfway up the stud) to allow for proper seating of the studs against the flange holes' outside periphery.

Luckily, my friend, who was helping me with the stud installation, had a lathe and was able to machine the studs so they'd thread into the flange holes, all the way.

3. This is a small thing, but the machine work (drilled holes, in particular) had no "finish" work done to it, leaving rough edges on all the holes, with machining "debris," still attached to the side of the hole-edge. My machinist friend thought that was really sloppy, and took a chamfer tool and smoothed all the edges before we installed the studs. For $555.00, I expected more...

Am I unreasonable?

Did you check with Moser before having the access holes drilled in the axle flange? This may throw off the balance of the axle if they weren't designed for them. The flanges on aftermarket axles are heavier than stock and will give a small vibration if not balanced.

Which studs did you use? The axle should just be a threaded hole for the stud. Axles made for screw in studs take a special stud, they look just like a bolt, some race guys I know just use hardened 1/2" allen bolts.

I do agree that they should have them cleaned up with no burring or sharp edges.

 

[Bill Dedman]

Did you check with Moser before having the access holes drilled in the axle flange? This may throw off the balance of the axle if they weren't designed for them. The flanges on aftermarket axles are heavier than stock and will give a small vibration if not balanced.

The stock axles have three holes; one large access hole and two balance holes on the opposite side of the flange (like 12 o'clock for the bigger hole, and 5 and 7 o'clock for the smaller balance holes.) I had the machine shop duplicate that setup, so, hopefully, the balance should not be disturbed.

Which studs did you use? The axle should just be a threaded hole for the stud. Axles made for screw in studs take a special stud, they look just like a bolt, some race guys I know just use hardened 1/2" allen bolts.

Moser sent 11/16"-studs along with the axles, that fit the holes they had drilled and tapped; they worked perfectly after the shoulder was machined down so they'd bottom out correctly.

I do agree that they should have them cleaned up with no burring or sharp edges.

They went right in, with zero problems getting them to register in the axle gear splines.

I just thought they shouldn't have had the problems they did. I don't own a lathe, and would have been greatly inconvenienced if my machinist friend hadn't offered to help. And, he's a Chevy guy; it was very embarrassing... LOL!

 

[Blownfish]

They went right in, with zero problems getting them to register in the axle gear splines.

I just thought they shouldn't have had the problems they did. I don't own a lathe, and would have been greatly inconvenienced if my machinist friend hadn't offered to help. And, he's a Chevy guy; it was very embarrassing... LOL!

As long as everything worked out in the end, it is all good.

I think some of these bigger companies loose sight of the customer as they become bigger. I've had more problems with these companies over the last 25 years than you would think.

I am making a space on my trailer once I repaint it for a wall of shame, it will have decals of all the companies that sent me faulty parts or had bad customer service. I will have an explanation of the issues with each company next to their decal.

I had major problems with JE pistons more than once with the same order.

BDS sent me the wrong intake, not once but three times.

Edlebrock wanted their heads back badly after I found a few flaws in them, but they never sent the call tag so I did it myself.

Eagle failed to mention a few important issues with their cranks.

I had my rear chassis work done by the guy that build Gliddens cars back in the 80's and even with that background I had to have him redo a few things and I ended up fixing them myself.

The company that built my first cage extorted money from me. I had since cut it out and built my own.

The most recent is with California car covers that screwed up and now wants to modify the cover I have instead of just starting over. I paid for a custom cover, not one that has been modified several times.

I could go on but I don't see the point. The bottom line is there are very few companies out there that really care about their customers, most think that buying from them is a privilege in itself.

 

[65Vart]

Chrysler 8 3/4.

8 3/4 is the best bet . Best of both worlds for lightness and strength. The Dana is a great rear end but heavy. Ford rear end is also pretty heavy for an ABody.

 

[Duster346]

 

[fstfish66]

8 3/4 wont take the power ???? drag racers,,,and blown dragsters of the 1960s running blown fuel engines perferred the mopar 8 3/4 & the 1957 olds rear end,,but try to find one of thoese these days,,,big daddy don garlits used them,,i guess he didnt make any power,,,also,,i am no expert on FORD OR FERD,, OR??? but i have heard and read that some of the 9 inch ford rears have a different type or extra bearing that actually slows down the car by about 30 horse power,,ask some guys that have switced from the 9 inch to a dana,,,they picked up at the drag strip,,, an 8 3/4 will take what ever any opther rear will on the street,,just dont use a GM 10 or 12 bolt junker:read2::read2:

 

[Duster346]

<--- 8 3/4 in this car did fine. 10.08 @ 130, 1.38 60 ft.

Better than a 9"? I wouldn't say that.. just as good, I would say yes, it CAN be. The smaller ring gear and flimsy housing will always be the downfall of the 8 3/4, but there are fixes for that .. to a point (horespower).

Also depends who builds it, and what parts are used ..

Riddler won't be making a bunch of power, but he's looking for something that's easy to install, reliable, and affordable.

The 8 3/4 takes some modifications to work in high HP apps.

Pro Stock uses a 9 inch 'style' housing with an 9.5" ring gear ......

 

[razorback]

i think a 9 inch is a good idea over a certain level, i would lower that level if you were using a manual, since they are alot harder on the rears than autos are. i honestly think you would be ok with a 8 3/4 if you have an auto, there are plenty of guys making big hp with the ford 8.8s too.

but it can be overkill, since it would take more hp/tq to get it to move and add weight to the overll call. ford 9 inch stuff is alot cheaper, and common though.. im currently debating on making the viper rear i have work, getting an 8.75 or finding a cheap 9 inch.

dont forget to try www.car-part.com for parts local to you.

 

[sydcuda]

8 3/4 wont take the power ???? drag racers,,,and blown dragsters of the 1960s running blown fuel engines perferred the mopar 8 3/4 & the 1957 olds rear end,,but try to find one of thoese these days,,,big daddy don garlits used them,,i guess he didnt make any power,,,also,,i am no expert on FORD OR FERD,, OR??? but i have heard and read that some of the 9 inch ford rears have a different type or extra bearing that actually slows down the car by about 30 horse power,,ask some guys that have switced from the 9 inch to a dana,,,they picked up at the drag strip,,, an 8 3/4 will take what ever any opther rear will on the street,,just dont use a GM 10 or 12 bolt junker:read2::read2:

Yes, in fact the 9 inch diff has a smaller pinion diameter pinion shaft than a 741 carrier, the weakest of the 8 3/4 carriers. What saves the 9 inch is an additional pinion shaft support bearing.

I'm surprised to hear so many guys over there extolling the virues of the 9 inch over the mopar 8 3/4. If you think 8 3/4s are scarce in your neck of the woods try finding one here, or importing parts for them! Yet I'm near finished building an 8 3/4 for my cuda, shortened housing, new axles, etc. and for less than $2000 AUD.

I couldnt be happier being able to say my mopar is allll mopar. No one can say my car is part Ford. And as for "doing things your way", as someone here said, there's nothing new about corrupting the mopar bloodlines by installing a 9 inch. Why feed the delusion that the 9 inch is superior to mopar?