Right - the ONLY difference between a 9" and a 10.25" is ring gear size. The tubes, tube walls, axleshafts, spline count, bearings... Everything else is exactly identical, so you caught me!

[/sarcasm]

 

It's not my fault you didn't mention all that

Tubes and their thickness don't REALLY matter all that much. I mean, if you are bending axle tubes, you're doing something too By the way, and this isn't sarcasm, what are the axle shaft diameters, spline counts and bearing size difference between the 9", 9.75" and the 10.25"?

Also, one last question, what axle does a 5.4L 03 carry? I know for sure it's not an 8.8, but I don't think it's the 10.25"... seems like too much for a v8.

 

I said they were stronger, but this thread isn't about them, so no: I didn't go into detail. If you want to know all that, I suggest some research with Google, etc. You could make a good start here:
http://www.drivetrain.com/ford8.8.html
http://www.drivetrain.com/ford9.75.html
http://www.drivetrain.com/ford10.25.html
Go back to that home page for more options & the menu bar.

Yes, tube diameter & wall thickness have EVERYTHING to do with an axle's strength. That's what ALL the loads go onto, so that they get transmitted to the suspension, & ultimately to the chassis. That goes for full-float, semi-float, & even portal.

The axle would depend on the chassis, but ASSUMING you mean an F150, it should have the 9.75". But V8s do just fine with the 10.25" - there are plenty of them out there, since the mid 80s. You can probably even find a few 4-bangers that have them swapped in.

 

Currie? Read about them first in the early 80's, and the sales literature sent to me was printed in black and white, but no, who are they? Maybe you need to do some searching yourself. From Robert Eckhardt of HOT ROD:
"By the mid-‘70s, the company (Currie) had a stockpile of over 50,000 used rearends spread over two storage lots. Today, it has only about 2,500 backup units left on hand. It buys them in Mexico, Canada and from all over the Midwest US. Passenger car rearends are preferred over those out of pickups because the car rearend in most cases still look new. Even though truck rearends’ center section and the gear case are usually usable, because they run more miles and haul heavy loads, the axles, brakes, and gears are trash. Three years ago, Currie was paying $20 for a core housing. Now, it has to pay $60 and it’s going to keep buying them until there are not anymore left. Currently the company can only obtain about a quarter of its needs. Supplies are about dried up and there are simply not enough Ford rearends left to meet demand."

When I said "in production" I meant being built on a steady production line, not an aftermarket company building items as needed. Example: Grant makes steering wheels--as needed to meet demand. Ford/GM/Chrysler's steering wheel supplier's turn out thousands daily on production lines. Custom bike shops manufacture turn key bikes out of parts. Harley Davidson runs a production line. The Boss 429's were finished up by Kar Kraft, the Mustang-- well, you get the point.

Magazine articles written by people who wheel and build axles? What does that mean in English? Axle builders should stick to building axles, and leave the article writing to writers. And when exactly did they begin to think silly like that anyway?

And we're going to talk about strength? Well, I don't know if you've been paying attention, but Ford doesn't trust them behind a 5.4, let alone anything big. When a 9 inch can take the beating that 351 Clevelands, 390's, 427's, 428's 429's & 460's can dish out, why would anyone want to stick a sissy V6 rear in their truck? Yes, I know that Ford uses them in V8 cars. Means nothing when talking about trucks. Ever see Ford put an 8.8 behind a big block anything? Nope. They know better.

Oh yea, the second pinion bearing? Different angle-> better design->necessary item->stronger rear.

8.8's? Hey, if you like 'em, you use 'em. I don't and won't. End of discussion.

SL

 

Quick question to toss into the crossfire! Is there any external way to tell what rear-end my truck has? I was told that the 8.8" had a drain plug on the rear coer and the 9" doesn't? Is this true? Thanks

 

No, the THIRD.OKNo, neither has a rear plug. But the 9" doesn't have a rear cover - it has a removeable carrier (3rd member/CHUNK). The 8.8" has an integral carrier & a rear cover. Click my signature link & look in the Diagrams album, & in the 8.8" Axle album.

 

DAMM Steve, you're everywhere. What caused you to wander over here?

 

That's easy to figger out - just find my first post.

 

How many stock cars race with front wheel drive? Hmmm they change to rear wheel drive because its supperior. How many stock cars run 8.8 rear ends?.... Anyone? Anyone? How many use a version of the 9"? How about most of them, for 20 years or so. The 8.8 is a strong version of Chevys 12 bolt. Ford quit making the 9" becuase they no longer made muscle cars with 429's, 428's, 427's, 390's etc. When cars quit getting motors that made gobs of torque they went with a cheaper rear end. The 8.8 is cheaper to make. Thats it, do the math.

 

Right - it couldn't POSSIBLY have anything to do with the complex racing rulebook & the economics of making any changes. Or with the time & trouble for all the race teams to make the change. Or with any of the parts suppliers lobbying against any change. It can ONLY be that the 9" is SO superior that Ford scrapped it 20 years ago. Because it's obviously MUCH cheaper for Ford to design a whole new axle & retool for it, than to just add a VSS to such a superior design as the 9".
[/sarcasm]

And I don't believe ANY stock cars "change" to RWD. They build a RWD chassis & slap a fiberglass body onto it.

And your "muscle car" BS doesn't fly either - what about all the TRUCKS whose engines produce "gobs of torque"??? Like my 4.9L? It was Ford's STOCK engine for ~13 years AFTER the 9" was dropped, and it has earned a reputation as a torque monster. And it makes LESS torque than any other FS truck engine. Remember that we're on a TRUCK BBS, & that the F150 was the best-selling vehicle in the WORLD for a few of those years. Certainly THAT would justify continuing production on such a FINE hunk of steel as the 9", right? RIGHT???

I guess the 9" isn't all that strong after all, is it? If it was, it would still be in mass-production.

 

You know, I still dont' believe you

 

I thought I had posted my final entry on this subject, but I 'll add one quote from Chris @ Currie Enterprises, which, BTW, do both 8.8 and 9 inch rears:

"In stock form the 9” is superior in every way. There is nothing that a 8.8 can do better than a stock original 9”

Thanks, Chris "

That's what I thought as well.

Thank you Chris

SL

 

Personally 2 of the 3 8.8's we have hum like no other. Both under 100k miles, one behind a mighty 4.6 (90k), the other behind the mosterous 4.0 SOHC (60k). I would be hard pressed to brag about that axle. I think the fact that some drag tracks don't allow c-clip axles and that Ford doesn't put them behind anything bigger than a 4.6 should speak volumes about them. If the 9" isn't stronger stock, the huge aftermarket would make them.

 

...except the HUNDREDS OF THOUSANDS of 5.0Ls, 5.8Ls, & even a few 7.5Ls & 400Ms. Yeah, except for those: nothing larger than a 4.6L.

 

OK, nothing larger, HP wise. Back when Ford was putting them behind bigger CID motors, the motors were much weaker. 400's (mine anyway) in 1981 put out 166 HP, the 460's maxed out at what, 245-250? Weak motors don't typically break rears, that's why 4 cylinder cars hardly ever had diff. problems.

400's? The last year of any of the 335 (351C, 351M & 400) series in was 1982. The first year of the 8.8 for trucks was 1983. For cars, as early as 78, but even then they were only rated 1/3 stronger than the junkbox 7.5" , and only put behind in intermediate (small) cars w/ wuss motors anyway. Even the 5.0L was a wuss motor before multiport. Afterwards, OK, but could've been better. CAFE killed all it's power.

460's? Talk about an accident waiting to happen. Ford must've been testing the how thick the ice was.

5.0's and 5.8's in the trucks were underpowered pigs. What, 210 HP max? Out of a 5.8L? Big deal, an 8 inch could handle that.

In all fairness, they could probably take about 230-240 HP and survive, but do you actually believe you could throw one behind a 300-350HP motor and not have problems? I don't, and apparently Ford doesn't either, and they know a hell of a lot more about that rear than you or I ever will. They've been testing it for 28 years on the street, they know what it's capable of, and what it's not.

SL