This is another one that I almost hate to post. I did a search but I get lots of posts that show everything and your grandmother except what I need.

I have the chance to swap my 8.8 rear axle to a 9 inch at a very reasonable price.
The question is what do I gain other than .2 inches?

Is the 9 stronger?

Is there more available parts for the 9?

Thanks

 

If this is going into your 96, good luck. Many are able to get away with with swapping the 8.8 out for a 9", you woun't be so lucky. First off there is no provision in the axle for a VSS, and because your truck is auto, you NEED the VSS for your truck to know when to shift gears. The 9" is a stronger axle, and with it's huge aftermarket support could be made very strong. But in your case, if you looking to go bigger, go with a 10.25, although it's 8 lug, it has a VSS.

 

yes the 9" is stronger (I snapped a 8.8 main cap running 33's with a tired 2bbl 302 and a automatic).

as far as bolting it in you can have the driveshaft lengthened or find a driveshaft from a 80-86 truck with a 9"

if you need VSS or a ABS tone ring think about a sterling.

 

he's got a 96 E4OD...that thing will be all kinds of messed up without the VSS. I have also swapped in a 9", i have a 93, still have no VSS but i have a manual tranny, it drives fine but, no speedo. If i were to do it again..1 ton 10.25" is the way to go, that sucker is one tough axle.

 

Along the same lines only different years the wifes 89 bronco has the 8.8 with the VSS in and I was thinking of changing it out for the 9" since the abs doesn't work anyway. is the 89 set up different cause it has what I thought was a speedo cable hooked to the transfer case and I thought that ran the speedo, and the reason the abs isn't working is the code says the VSS isn't working yet the tranny shifts just fine but isn't 89 an e4od also or is it just the AOD can't remember on this one.

 

In the 89 you should be ok, now i could be wrong but i belive that old the speedo ran off the tranny and all the vss did was abs.....again..theres a 50/50 chance i'm wrong on that.....

 

Thanks ryan thats what I was thinking too but these other ones got me scared into asking before I tore into changing the diff just wanted to make sure it was gonna make me change the engine, and tranny too.

 

In response to the original post:
The size of the ring gear itself isn't going to be significant. The biggest problems with 8.8 is the crush sleeve which looses its preload and strips the threads of the pinion at the same time. When intalling a new gear set or bearings, that is remedy by a $12.00 solid spacer. The bearing caps is another problem and it can be remedied by a reinforced diff cover that supports the bearing caps and those covers reinforce the centersection and increase oil capacity as well. Those are simple improvements on the 8.8. Radical improvements could include Torino style 9" housing ends that would allow the use of larger 9" style wheel bearings, 9" axle shafts and eliminates the c-clip as well. In my case, I even have .25" chromoly tubes.

Other VSS options would include going with Sterling 10.25 or a tone ring equiped D60.

The philosophical debate over which axle is the best doesn't hold up really. Both axles have their strengths and weakness and don't reach their potential unless they are "built" to some degree. Its a lot like arguing over who the best line backer is between Reggie White and Lawrence Taylor. I'd have to say Reggie since we are both UT alumni!

 

I also have always thought that the only problem when swapping a 9" into the newer trucks is the loss of the rear abs, never even knew about the tranny issue thats been said here.

 

Thanks guys now I gotta find out what VSS means :-)


RLH - Is there a standard "built" package or other items I need to know about the 8.8 that will lower the odds abainst blowing it up?
I am running 35" and really trail ride. Climbing rocks are only "if they get in the way" issue.

I am not a wrench. I am a user with minimal mechanical ability but I have a mechanic that will do what I ask. I just want to give him the right path. He is a racer with some off road experience.

Thanks

 

Putting on a reinforced diff cover would be simple enough. It would take a fair amount of labor to replace that crush sleeve with a solid spacer which is a $12 part which would be a good excuse to install alloy axles.

You can probably get a Trick Flow diff cover for the rear for $129. Its a bit spendy but they have supports for the bearing caps and also girdle the centersection and darn near double the gear oil capacity.

Edit: Should intall alloy axles and/or regear, get a bebuild kit ~$80 such as the Yukon one that has all Timken bearings, just replaced that crush sleeve if it comes with one.

 

The best thing I like about the 9" is if you snap an axle, it won't come violently flying out of the axle.

The other pluses with the 9" is it is easily upgraded to 35 or 40 spline axle shafts and heavy duty spool or 35 spline detroit. The 9" has a wealth of upgrades available, and it has an upper and lower pinion bearing (more strength) and has a limitless selection of gear ratios. It is also super simple to pull axle shafts on the 9" (4 bolts and minimal fluid spill). If you have a 9", it is light and easily upraded to be as strong or stronger than a Dana 60 (not to mention lighter)

however, on the other hand with the 8.8" you have to use leaking c-clip eliminators to retain the axles, or weld 9" housing ends to it. I also don't think you can get any bigger shafts than 33 spline, and the gear ratios aren't quite as bigger as the 9".

Factory equipped, the 9" is only a bit stronger than an 8.8. The newer 8.8s are better for newer trucks since they have VSSes. A newer 10.25 with a VSS & tone ring would be a much better choice to swap in a late model truck.

Bottom line- the 9" _is_ a better axle. However, im factory form, I wouldn't swap unless I broke the 8.8 or needed a different gear ratio. (I broke my 8.8, so I'm swapping my 9" in my '85).

 

Since I made the post a few days ago, Reggie White passed away which kinda weirds me out just a little. He was a role good model the way pro athletes should be. He was also a mighty Volunteer.

 

from what i have seen the 8.8's weak point is also the pumpkin castings cracking, or spining on the tubes, id truss it, put a pre-load cover on it and carry spare shafts. or go 10.25 like i did and be done with it!

 

The old Sterling 10.25 has been known to spin a tube and leak like hell.