This post is a work-in-progress -- I'll be editing and updating it as I write more, but I wanted to get it started or I'll NEVER get it done!!! Feel free to comment and share experience, knowledge and questions in posts even though it's not done.


I will begin to explain some of what's involved with doing a full carrier replacement, and some of what you are looking at doing it with a Ford 8.8 axle. I've only done it with the Auburn ECTED, but I bet most of it is relevant no matter what you do.

There are two broad cases you will encounter: Keeping your ring and pinion -- or -- Using a new ring and pinion

The case of keeping your old ring and pinion is the easiest. One assumes that your existing ring and pinion are already set up properly.

Most of you will be doing this to your existing axle, and keeping everything but your old carrier. This means the only bearings you need to replace are the carrier bearings. If you decide to replace your axle bearings and seals, keep in mind which axle you have when buying the bearing set. 28 spline axles have 2.25" diameter axle bearings and seals, and 31 spline axles have 2.5" diameter bearings and seals. You can pound out the old bearings with a long pipe with the differential carrier and axle shafts removed. When you reinstall the new ones, use a method like in note number 9 below.

Basically, what you will be doing is taking out the carrier and removing the ring gear and "tone ring", then putting that and new bearings on the new carrier and reassembling the carrier into the axle. You will NOT be doing ANYTHING to the pinion and trust me that's a blessing!

Some things to remember if you are keeping your existing gears or not -- that is, things that always apply

1. Bearing caps and the recess for the bearing race on the differential housing are individually machined. Make sure you mark the bearing caps "R" and "L" and don't mix them up. Mine came unmarked with the used axle already disassembled, but there were marks on the inside that made it possible to figure out which was which, fortunately.

2. You will need the tone ring from your old differential, or a new one. I had a bad LS carrier that was given me with the axle (it wasn't the one that came in the axle) so I had one to remove a ring from. I'll cover taking off the ring gear later.

3. With some differentials, the center pin will not come out enough to install the c-clips if you have high ratio (4.56 and up, but maybe 4.10 on some differentials). You will have to grind a flat on the pin so it can be turned 90 degrees and slid out enough. The differential installation instructions cover this, but not real well in the case of the Auburn ECTED since the instructions reference a pin from their cone type LS which is slightly different. The difference is where the retaining bolt goes in -- but if you're new to it, it can make you doubt what you're about to do as you are about to modify a key component of the diff. I didn't want to modify mine, and tried to assemble it without doing so (I changed to 4.56 gears) -- but that turned out to be a time waster. Almost none of you have anything but 4.10 or lower in your truck already so this probably doesn't affect you.

4. You absolutely must shim the differential carrier per the instructions, and you must use either the feeler gauge (iffy) or micrometer (preferred) method to determine gear lash. FAILURE TO SET PROPER LASH CAN CAUSE CATASTROPHIC FAILURE OF THE DIFFERENTIAL.

5. Observe all torque specs. Beg, borrow, or liberate torque wrenche(s) of the proper ranges.

6. Read all you can about the procedure (NOT JUST THIS POST) before you try anything.

7. You must either heat up the ring gear and the carrier bearings to install them, or press them on. I used heat, but either works. You will find references to it in full install instructions. Do not exceed 300 degrees. You do NOT heat the carrier itself!

Some additional notes for those doing gear swaps

8. Like the carrier bearings, the inboard pinion bearing must be pressed on the pinion shaft, or the bearing heated so it will go on. In either case observe the warning about not overheating the bearings.

9. The ouboard pinion bearing is pressed into the differential housing. A large socket or pipe that fits in the hole in the housing can be used to hammer it home (hitting the pipe or socket with a hammer, not hitting the bearing). MAKE SURE THAT THE PIPE OR SOCKET ONLY CONTACTS THE OUTER RACE OR YOU WILL DAMAGE THE BEARING! Use as much force as necessary on the hammer, but you don't have to be a total animal to get it in place. When you remove the old bearing by hammering from the inside, it doesn't matter if you damage the old bearing. Make sure the new bearing seats all the way down.

10. The pinion uses a crush sleeve under the flange to ensure you can have lots of torque on the mounting nut, without overloading the tapered bearings. This leads to confusion. You will be told the nut gets tightened with 300 pound feet of torque to crush the sleeve, but then you are warned not to exceed a bearing preload torque of 19 to 29 pound INCHES! This is not an error. The tightening torque is with the pinion IMMOBILIZED to tighten the nut. The preload torque is how much force is required to turn the pinon freely after the nut is tightened down. Failure to tighten the pinion nut enough will result in play in the pinion and eventual failure. Too much torque will result in excessive bearing wear.

11. Shims need to be CLEAN when installed. Excess oil and dirt on them artificially inflates their thickness when stacked (and you will be stacking them) but then that will go away after a time in use and everything will "open up" -- you don't want that. Wipe them every time you handle them if you can.

12. As I mentioned previously, particularly in the case of the Auburn LS and ECTED, you must do something if you have gears over a 4.10 ratio. For those gears, you have to take the center pin out of the diff and machine/grind it down with a flat on just over half it's length, about 1/10" deep. OTHERWISE, you can't get it out enough to push the axles in far enough to get the c-clips on -- ask me how I know... I ended up having to take the carrier out, remove the ring gear from it, remove the pin, grind it down, and put everything back together before I could get the axles in!

13. You may have a problem with the ECTED if you have a 31 spline rear. The splines on some axles (the right one in particular) aren't cut along a long enough portion of the axle. The ECTED has one very long splined spider gear for the right (passenger's side) axle. The result of this is that the 31 spline shafts on my FX4 axle wouldn't go all the way in far enough to put the c-clip in. I actually had to grind away on the shaft a bit just behind the splines, to the depth of the splines, to allow the axle to go in far enough.

I'll be posting on this further, but thought I'd share these hard earned words of wisdom.

My buddy Billy at work helped me with the setup. He thought it would be a 1 hour job but he didn't catch that I wasn't using the original pinion and ring. Hence -- it's a lot more work.

You have to press the bearings on the differential and the carrier. Not a home job unless you have some kind of press. You can also heat them up and drop them in place, which is what our machine shop did after the inspected the bearings and decided they didn't have any plastic in them.

To put the ring gear on, you heat it in the oven. I did mine at home by putting it in the oven set for 250 for about 1/2 hour. It just dropped in place then. Line up the bolts, put a couple of them in, and you're there.

Here's some of the VERY few pictures I took during this. It's too dirty and nasty for much of it to use the camera -- especially working much of it alone.


Billy gets some shims together for the adjustments.



Looking into the rear, you can see the black magnetic coil on the right that engages the locker (note the wires hanging). Runs on it's own bearing. The rear is shimmed here to about the right lash, and we're about to check the mesh. The pinion is in with shims, and the bearing pressed in the housing and on the pinion, but without the crush sleeve for a trial fitting.



Billy is painting on the marking compound that will allow us to see if the gears "mesh" correctly. If they don't, we'll have to try different pinion shims. I "guessed" that we should use 0.036 shim (thicker than normal) because of the high ratio. I turned out to be right on, but not by skill. My best guess based on what I read was correct. Billy had no idea where we should start so I just read everything I could get my hands on about Ford rears and it was suggested by some installers that 8.8's with high gear ratio's need somewhat thicker shims between the pinion and the bearing. If you guess wrong, you have to press the bearing off, put new shims on, and press the bearing back on again



This is a near perfect mesh pattern! Hooray! This was on Friday about 2PM -- getting late since I want to use the axle the next day. The master rebuild kit I used had instructions to show you what were acceptable mesh patterns.



Putting the pinion back together with the air gun. It wasn't enough to crush the sleeve. When we put real torque on it, the screwdriver you see holding the flange snapped like a twig and we had to use bolts instead. THEN we could hardly keep the axle DOWN while we torqued. Sometimes you just can't win.



Then of course, the air gun falls apart and little pieces go missing. What a day...



Let's just say doing it from scratch with a new carrier, ring and pinion is a lot of work, and sometimes you end up backtracking.

 

Great info, John! Thanks! I've saved the whole post w/pictures for future reference.

 

Thanks, Bob. I'll be adding some more about what happened and some of the mistakes I made rebuilding this one to hopefully keep others from wasting as much time as i did!!!

 

John I believe you are out growing your elelectrical goo roo status. You have now evolved to something bigger and better. (I don't know why mad scientist comes to mind)

 

LOL ain't that the truth. Awesome work, It'll be awesome to see how it comes out and works!

 

Oh it is awesome. We got to see it in action in Centralia.

 

worked like a champ

 

Well, got up at 4AM this morning and went out in the snow and ice we had to meet some friends from work who are mechanics. I needed to get something looked at and I didn't want it to wait.

They had to show up a 5AM anyway, just to be there, and said we could look at my truck.

Here's why: over the past month or two I've been hearing an increasingly louder rhythmic tap, clack or knock coming from the rear. It would only occur on coast, but sometimes when you hit the gas, it would clunk once.

I thought it was the u-joints and bought new ones but when I dropped the driveshaft the u-joints were just fine.

However, the pinion was loose. It had lateral (back and forth) and radial play. Not a lot, but enough to feel very WRONG.

Turns out we didn't crush the sleeve enough and the stress had crushed it more, but of course the nut hadn't moved so there was now play.

We disassembled the diff and took out the pinion and miraculously the bearings a races were all still fine and unscarred.

If you look at my step 10 above I can tell you what we skipped: we didn't have an inch pound torque wrench in the correct range. Billy gave it his best guess but he was wrong and we hadn't tightened the pinion nut enough.

There looks to be some possibly funny wear patterns on the ring and pinion from this, but not enough to suggest any serious wear or potential failure. So we put everything back together and DID IT RIGHT this time and everything seems fine now with no funny noises.

I did find out two other things though:

1. The ECTED bias is very loose now unlocked. It's not much of a limited slip at this point I don't think.

2. There is a bit of "wiggle play" in the center pin. My other mechanic friend thinks the instructions showing how to grind the center pin are poor. It shows grinding them on the "face" (it's a round pin, but you know what I mean) where the hole for the center pin bolt goes. In fact, Matt says it should be ground at a point 90 degrees around from that so that the force against the pin doesn't vector in the direction of the flatted pin face. He feels that's what started the wearing of the hole. The pin has to be flatted with 4.56 and higher gear sets to be able to get the c-clip axles out.

Could be a Dana-60 rear is in my future, lol. This one can go a long time like this though.

I want to see what Auburn says about this. I'm hoping they take some responsibility for this, but they may not, who knows?

 

There is some very helpful info in this thread,thanks.

 

holy old orginal post... lol.. great little write up tho! imma save this also.. for future references i may have

 

Thought I'd share the failures as well as successes, lol.

Well, that axle has kicked butt for two years even with the mistakes we made. In my truck, the rear axle gets used pretty hard offroading in 2WD -- there is no front axle to share the load, lol.

Just don't want anyone else to shortcut or guess as we did and end up in a similar dilemma down the road apiece. I was quite concerned that I might have to swap out the whole axle if damage had occurred to the housing or something.

 

haha ya i kno how it is to wheel hard on only the rear axle... im kinda surpised mine isnt gone yet.. i gotta tear mine down and do some crap to it.. pretty much just basic matience tho...hey are u gunna be down here this week or weekend john?.. ya BTW it's always better to kno something like this before, then later lol

 

It'll be in April I come down. Flying in on the 21st, and back on the 25th. I know Sunday and Tuesday nights are committed -- don't know which of the other nights is best but it might be nice to get together Saturday night or something after I get checked in at the hotel.

I'll be posting back in that topic I started on it when I get more info.

 

I'm happy to report that so far all problems with the rear axle are gone: no pinion seal leak, no noise, no "looseness". All feels right and tight and it doesn't appear to be getting hot either.

Phew! Hope it's okay -- I really didn't want to be spending SAS money fixing up the rear.