All I can seem to find is 8.8 vs. D44 information. How about 9 inch vs. 8.8?

From searching I found that a 9 inch out of a Bronco is a common swap for the YJ. Any other vechicles and any specific year Bronco?

Also are there any major benefits for running the 9 inch over the 8.8. I want to run 37's so I think the 8.8 should hold fine but if swapping a 9 inch is about the same cost and gives improved strength then I might as well do that.

Another reason for the 9 inch over 8.8 is my Wago 44 front is 62 1/2 while the 8.8 is 58 3/4. Does anyone know the width of an 9 inch.

TIA and if I missed a thread explaining my questions please point me to it.

Brakes on the 8.8 most likely are disc... Big advantage if you ask me.

Strength is a little bit weaker but not enough to worry about.

Do it.

Do what the 8.8 or 9 inch?

I don't know much about the 8.8 but to say it will be fine with 37's is kind of a stretch, maybe I'm wrong, but if i was going to go that tall I'd seriouslly look at a 9" or D60, you might not have problems, but I'd say you'd only be marginal in strength.

9" vs 8.8, while an explorer 8.8 is an easy way to get a stronger YJ axle, it comes with 5 on 4 1/2 bolt patter, and I've heard the flanges are two small to be drilled for 5 on 5 1/2 or 6 on 5 1/2, like your front. What's your plan on bolt pattern. It is also C clip, and while the disk brakes will hold in the shaft if you break on, the flange style retainers, I think are far superior. I don't know much at all about the full size 8.8's used in Ford 1/2 in the 80's, I'd say the reason I haven't is that they aren't a very good swap canadates. Few 9" came with disc brakes, but you might find some on an older car, of course I would imagine there would be a pretty significant cost savings going with the nine, maybe enough to upgrade to aftermarket discs. A nine also has almost an unlimited upgrade potential, the thing has been around for 30 or so years, and is common in the drag racing circuit, meaning many used parts, and upgrades are available for it.

I don't know what you got planned for the jeep, but if your going to the trouble to fit 37's, and bother to swap an axle, I'd seriously look at a 9" or a 60", it might take a little more work, but it beats doing it twice...

Chad

The disc brakes are a MAJOR ADVANTAGE in my opinion.

Do the 8.8 Sorry i forgot to type that last part... oops.

I am running an Explorer 8.8 in the rear of my tj. Disc brakes, 31 spline Dutchman shafts 5x5.5 pattern, Detroit, 4.56, 36" tsl/sx. No problems at all.

The 8.8 seems like a good canidate, H8Monday and Rockbuggy both run it with 38's. I think that's all on here that run that axle with such big of tires and they haven't had problems.

Does anyone know of any tech articles on swapping in a 9 inch? I would like to see what modifications has to be done to it for it to be swapped in and what vechicles I can get it out of.

Also any stories on the 8.8 breaking would be good. So far I've only heard H8Monday breaking a shaft. And of course I would be replacing the carrier.

Originally posted by attachcurrie
So far I've only heard H8Monday breaking a shaft. And of course I would be replacing the carrier.

H8 runs a 14 bolt now.

http://www.google.com/search?hl=en&q=%22ford+9%22+jeep

:rolleyes:

Some 9s are stronger and can be built alot stronger than an 8.8.

you can get disks off of lincoln continentals.

What about the smaller Lincoln from the early '80's? I think it was called a Versai. It might have a 9" w/ disks @ about the right width.

I can't speak for the 8.8 but I've run a Disc brake, 31 spline, spooled 9" in a CJ-7 with 36's for a couple years now. I just had it apart for inspection and it shows no sign of wear or fatigue anyplace. It also is 58 3/4 with a 62" waggy front. At first I was going to change one of them out to get the same width but after running it for awhile I actually like it. I like the way it tracks around obstacles and I haven't noticed a downside at all. FWIW

The 9" is definitely a more veratile axle. you can pretty easily uprgade shaft size (all the way to 40 spline 258% stronger than a 28 spline) and if the brakes are your only concern, call up TSM and get the brackets so you can run all off the shelf disk brake components.

Thant way you can have your cake, and get to the end of the trail too.

The main advantage of the 9" is aftermarket support. There are so many options available that it boggles the mind. Unfortunately many of them are not cheap. Disc brakes are a minor detail. You can upgrade any axle to disc brakes so the quetion of disk brakes being there already becomes a cost factor, nothing more. Strength wise I think the 9" and the 8.8" are pretty similar. The 8.8" is the replacement for the 9" so I think ford may have done their engineering homework. If you are worried about snapping axles then maybe you need to use something bigger because both the 8.8" and 9" use similar size axle shafts. You need to break the axle first before the c-clips become an issue. The 9" and the 8.8" came in many different vehicles so the question of width depends on what vehicle it came out of.

Paul you are right if you are comparing 31 spline to 28/31 spline, but the 9" also has 35 and 40 spline options (that don't require a housing change). The other benefits to the 9" are the drop out third member (a guy can have both a spool and open diffs sitting on the shelf. A 35 spline shaft in a 9" dwarfs the strengh og the 8.8's 31 spline best. 35 splines are the shafts used in HD Dana 60's. The 9" Ring and pinion are also far stronger than the 8.8. The Diameter of the ring gear is close, but the 9" has thicker gears with a larger gear mesh area.

Very true which is why I mentioned the excellent aftermarket support for the 9". :)

You da man! :smokin:

Originally posted by Karl Andraschko
A 35 spline shaft in a 9" dwarfs the strengh og the 8.8's 31 spline best.
Well actually you can build an 8.8 with 31 splines, 33, 35, and 40 splines..... just call Moser

Well, I went through this in my head, and I was about ready to go with a 9", eventually stick 40 spline shafts and a spool in it, with a nodular case. Then, an 8.8 dropped in my lap, for the cost of trading my D35 straight across.. Needless to say, I took it! Im working on gathering the few parts I need for the 8.8 and it will hopefully go in this weekend.... I HOPE. Like it was mentioned earlier, Rockbuggy, one of my good buddies runs an 8.8 with 5.13's and a detroit, and 38.5 swampers. He's pushing about 200 HP, maybe a little more, with a warmed up 4.2 with MPFI and a 4.0 head.. He hasnt broken anything yet. H8 did break on shaft, but remember he's running a V8..... :)
Scott

Well very good information thanks. So it seems like the 9 inch is the hero. Why would someone swap in a 8.8 over 9 inch when the 9 inch is so superior? The 9 inch seems to be a direct swap like the 8.8. How about the yoke on the 9 inch for my CV Shaft. Like the 8.8 has that little adapter, same thing with the 9 inch? Anything else from those who swapped in a 9 inch need to be done to it? Seems 8.8 all you have to do is weld new perches, connect brake and e-brake, connect adapter and bam ready to go.

Yes I did break axle shafts (yes, shafts as in 2 at once) on the 8.8, while I was running 38.50 SX and a 300 hp 5.0 engine. But the manuever I did that snapped the shafts, probably would have broke the 14 bolt Im running now. The 8.8 held up for nearly 3 years, of continuous abuse, with trouble free performance. I would recomend it to anyone running 36" to 38" tires with any engine. It is much stronger than the specs alone, might support. It is slightly below the 9" in overall strength, provided the 9" has the nodular housing and 31 spline axle shafts. But the 9" in my opinion has a pinion shaft that is too low. Yeah you can build the 9" with high pinion, or 35/40 spline shafts, and disc brakes,...but the price gets way too high. If you need tha much strength, build a 14 bolt for about 25% of the cost of a high dollar 9", and forget about it.
IMO the costof the 9" does not outweigh its slkight advantages in strength over an 8.8. and if its a low pinion, non nodular housing, 28 spline 9", its actually quite a bit weaker in many areas than an 8.8, with 31 splines and discs.

Thanks H8! What shafts were you running in your 8.8? Also any other mods to it?

Originally posted by attachcurrie
Thanks H8! What shafts were you running in your 8.8? Also any other mods to it?


I ran stock shafts, but Superior sells a High Strength replacement for about $120 a side.

Modifications:
I would highly recomend a full carrier locker, such as a Detroit, that replaces the somewhat suspect, stock carrier.
The axle tubes need to be stitch welded to the housing, so that they dont spin.
A larger vent tube should be drilled and tapped into the housing,(the small tube that is mounted on the driver side tube doesnt provide good ventilation, and can cause water to be pulled into, the bearrings durring water crossings).

i can speak highly of my hp nine (8.8) with detroit and 456 gears, 31 spline........ they have put up with my abuse..... is it bullet proof? nope but it is pretty stout.......... imho a regular nine isnt what we (offroading community) is looking for due to the extremely low pinion....

Did they produce any 9 inches that's diff isn't offset by much and is around 62 to 63"?

Originally posted by attachcurrie
Did they produce any 9 inches that's diff isn't offset by much and is around 62 to 63"?

Check out ford LTD's might be too narrow though, I'm not sure, and they're 28 spline.
-Nate

The early Bronco 9s up to '77 had a width of about 59" and a front D44 at about 61", but was standard rotation. The Bronco 9's from like 78 to 82 on were like 64" and they had reverse rotation D44 fronts until 81 or so when they switched to IFS.
The 9" came in a number of vehicles like the F100, 150, 250, Lincolns etc. The 9" from the vans is best used for a custom front, but blows in the back, since it's thinner and oddly proportioned. The one you want is a big bearing 9" with 31 spline shafts. If you can't find one you can order a flange that will accomodate the bigger Torino style bearing, but you'll have to cut off the old flange and wld the new one on. The bonus is you can use the Exploder disk brakes with the rotors that match your lug pattern. There are kits available to convert to disk brakes, and in doing so will increase, decrease or keep the width of the axle in tact.
The 4x4 aftermarket for parts is more expensive than the racing community Reider racing is a good source. Finding a used Detroit from a NASCAR team is a quick and easy way to score a good locker.
The nodular case is the way to go, and you can find one from a number of sources as well. The high pinion option is most likely something that passed through Currie at some point, and uses the 8.8 gears. There is a reason the Currie Fire Ant now runs on HP60s.
The 9 has some good strength adavtages which is why 400-500hp dragster and race cars still use them. You can also have a spooled and insanely low geared 3rd member you use for the trail that matches the front, and an open moderately geared 3rd for the street where you won't use 4wd.
The downfall of the 9" is the low pinion, but some people have their unit tipped back like 26* for the angle and don't have oiling problems. If it were to starve the pinion seal will go first and it's a quick fix. The rear shaft can help with some of the issues there as well. You have an otion on the pinion to use a flange or a yoke.
YMMV
Good luck

Actually many of the Pro Street 5.0 teams that are dominating the drag strips these days are running modified 8.8s instead of 9" axles.
Buy, and read a 5.0 Magazine, and be amazed at how much HP these guys are running through modified 8.8 axle assemblies.

Ahh. I feel so comfortable knowing that I can run tires up to 38" with no real problems. Im only at 35's right now, but will be at 37's once the SOA is done!
Scott