If your 88 doesn't have a speed sensor in the rearend, the 9 should be a direct swap. Pretty certain Ford never changed the spring pad spacing for that generation. A quick measurement with a tape would confirm that. Only other thing would be the driveshaft yoke. But that's easily gotten past too with a combination U joint if need be. Or just a yoke change. Brake lines should be the same.

 

The brake shoes and drums are likely the same, the backing plates would be different if anything.

 

This is the updated side/pinion gear kit (spider gears) The dealer said I needed. It includes all 4 gears, the thrust washers, and the cross pin locking bolt.
AL3Z-4215-B

But I have a question about one of the comments on the direction sheet. What special tool?
What are they referring to as “New Springs”

This is a pic of what the gears will look like ford has shipped me so you can see the parts.
I am particularity interested in finding out what the copper colored clips are.


Here is the partial instructions

 

They would fit behind the two idler spyder gears, i.e: the ones that the axles do not slide through, those two copper colored clips are the new springs that replace the old flat, wavy spring washers.

 

Thanks Baddad..
Are you talking about, I think they are called pinion gears? The ones that slide on the cross shaft..
After doing more research and getting lucky finding some pics and info... I think I may have part of my questions answered.
Through process of elimination going down the parts list:

AL3W-4215-AA Differential Pinion Gear, quantity 2 ---- We know what those are, they go on the cross shaft.

AL3W-4236-BA Differential side gear, quantity 2 ---- WE know what those are too!

AL1W-4214-AA Spring Differential Side Gear, Quantity 2 --- Those have to be what are commonly called side gear thrust washers... there is a set of thrust washers that fit on the back side of the side gears... If the “Spring” is not the same part as the side gear thrust washer then there is no listing in the parts list for the thrust washers..

387426-S101 Differential Pinion Shaft Retaining Bolt, Quantity 1 -- We know what this part is too!

1L2W-4B422-BA* Circlip, Quantity 2 -- Copper Clips --As far as I can tell those are NOT used in this differential... They are used only in Independent Front or Rear Suspensions. While trying to look up this part number I came across a diagram of where they are used...
Notice part #4B422 A, B,C on the diagram.. They must be the copper clips...




I also came across some other information that I hope is correct about this kit.
This being a updated part number and kit according to the Ford parts guy and according to the release notes at the bottom of the instruction sheet..
The pinion and side gears in the kit fit IFS, IRS, and Beam Axle Assemblies. I am not familiar with the term “Beam Axle Assemblies” but from what I could find it is a standard rear axle held to the vehicle with leaf springs like is on all of our 2 wheel drive vans.

There is a difference in the “original” side gears and the side gears in this updated kit.
The original side gears part #E7TZ-4236-A If you notice in the picture has a very small cut recess on the front side of the side gear down inside where the splines are.
In the new gears part # AL3W-4236-BA, the recess in the splines is much deeper. This is to accommodate the shaft locks on a IRS or IFS axle.
So from the best I can tell right now is that either side gear will fit in my 8.8 open diff..





That leaves one last unanswered question... What is the special tool mentioned and why is it needed? From looking at the diagram of the IFS differential there is possibly 4 of those copper Circlips used and the tool is for inserting them in place.


Here is the thrust washer on the side gear. The part the instructions is calling the SPRING



Might as well post the other pics too..
Thrust washer for the pinion gears. It has a lip that fits inside the gear itself.



One of the pinion spider gears



Here it is with the thrust washer on it.




Here is is all together



And last here is where one of the copper Circlips would go if this was a IFS or IRS diff from what I can tell and may be why the special tool is needed? It would go around the axle shaft and sit down into the deeper recess on the newer gears?

 

Beam axle is the Twin Beam front axle on 4WD trucks. The recess in the side gears the axle slides thru is where the "C" clips are housed in your rear end. Without those, your axles will slide right out on the housing. The cross pin is what keeps the axles spaced apart and the C clips inside the two recesses.Those copper clips are what keeps the axles in the IRS IFS differentials in place in the housing

 

It appears to me that you bought the wrong kit. Those sides gears will not work in your housing

 

You may be right Baddad but the jury is still out till I actually try to fit the gears in the differential unless you have some other ideas on what else I need to check. You have been a great help and I appriceate you taking the time to help. I am not disputing you or defending the parts I ordered, just trying to make sure I have the right ones and perhaps this info will help someone else that runs into this same problem.

This is the part numbers from the list NumberDummy posted with all the part numbers.
These numbers are for the side gear kit and there is no listing for the other two gears or washers that go on the cross shaft on that sheet. (not that I see anyway)

E7TZ-4236-A ,,, Gear kit (differential side) Use with axle # 720C, 724S, 730D - 1987/
Consists of:
E7TZ-4228-A ,,, Side gear thrust washer replaced by 2L2Z-4228-AA
E7TW-4236-AA ,,, Side Gear
-
-
After spending some time searching,,, E7TZ-4236-A ,,, Gear kit (differential side) most often is associated with all these updated numbers.

Updated numbers
2L1Z-4215-FA
4L3Z-4215-FA
6L2Z-4215-FA
9L3Z-4215-B
AL3Z-4215-B


I also did some checking on RA and found that the 1988 through 2006 E150s with a 8.8 use the same axle shafts, differential carrier, and spider gear kit. The differential carrier and spider gears are the same all the way up to at least 2014..

SO I called 3 other ford dealers and they all came up with the same AL3Z-4215-B kit originating from the part number E7TZ-4236-A on the list NumberDummy posted. They also verified that all the older part numbers superceded each other.

Still not satisfied, I called one of the larger differential shops in Atlanta and spoke with one of their mechanics. Without seeing the gears he seemed to think they would fit. I think mainly because he told me that if that is what Ford said I needed, they will work but he was familuar with the differnces. He also told me he had the originals in Yukon. Most productive though is that he told me I could bring the van down and he would put it on the lift and identify wehre the vibration was coming form for FREE!

Anyway from all I have gathered and not having the actual C axle retaining clips to lay on top of the side gears for a visual check, the retaining clip should still ride on the lip in the upper recess. Here is what I come up with along with why a tool is needed for the side gear “springs" and how to make one.

The guy at the shop said the new washers help to keep some preload on the side gears.





Because the new side gear "spring" thrust washer is wavy, it makes it difficult to install the other two gears. Like the side gears on differentials that have the clutch packs on each side of the side gears, the side gears have to be spread apart.

a home made tool.

 

You might be right. Looked to me when I last looked that the recesses on the C clip side of the axle gears weren't fully machined for the clips. I pulled my old ones out and looked at them, they have that slight lip inside the recess too. The final proof will be when you get the gears in with the C lips on the axles and the cross pin slides into place

 

The side gears should roll into place without needing a tool one will roll into one side of the housing, the other into the other side both at the same time. That's how they came out of mine just now.

 

Thanks Baddad for taking the time to verify that. Makes me feel much better about having the correct part. I'll try rolling them in first and then if I have a problem I will know what to do.. I have really learned a lot about axles in the past few weeks. I should have been writing down specs in a book though.. Help from you guys and going over and over this information and watching videos is somewhat like taking a class. I understand how it all works now and in what order the parts go in. I also understand where to check for runout and tolerances along with pinion depth and backlash. My next lessons will be learning to read the gear patterns correctly. I have the basics down but if i wind up using the old ring and pinion, I need to learn a bit more about the tolerances when using the old gears.

If the ring and pinion gears are still good then I need to take some measurements before disassembly and record them. If the old bearings are still good, they will at least a little worn. I read where one person recommended keeping track of the positions of the old bearings. Once I have them out, but them in a vice between blocks of wood and apply a little pressure, then measure the width of the old bearings.. Write the numbers down and then measure the new bearings the same way. That will provide the differences between the old and new bearings.

That is where it gets a bit tricky. Lets say the old and new bearings are the same exact width when measured. Now though I have to keep in mind that the old bearings do have a little wear and actually would have been few thousandths thicker when they were new. In this case that would mean that the new bearings that measure the same as the old bearings are actually a little thinner then the originals when they were new. In this case I would probably need to add a thin shim to make up the difference. Or the opposite was if the new bearings turn out to be thicker.

If perhaps the new bearings were only 2 or 3 thousandths thicker then the old bearings, perhaps I would get lucky and all the same shims would work first time around.

This thought might be important...
If I reuse the old ring and pinion gears, I don't think it would be a good idea to set the backlash to the specs for new gears as the old gears are already worn in and it might make them too tight.

A TIP I read... IF the pinion bearings are still good and tight with no rough feelings when you turn the pinion, and you are reusing the old gears, this can safely be done without a pinion depth gauge.

clean the face of the differential housing where the gasket goes and fasten a machinists square across the face of the housing above the pinion (before it is removed) and record the depth with a set of digital calipers. try to leave the device setup or at least mark exactly where it was and use it to measure the pinion depth when reinstalling it with the old pinion with the new bearings. Again one might take into account for a few thousandths wear on the old bearings.

It is still trial and error but still this should get one very close to the original specs.

I got it down how to set the preload on the pinion but still need to learn a bit more about preload on the carrier side bearings. The best method I have seen on this is to get the preload on the pinion set first and then install the carrier. With the carrier facing downwards and the pinon on top. check the total preload. I will have to look this up but there are specs for the total preload. Once all that is correct check the wear pattern and adjust as needed.

I know with new gears there is a break in needed. I think to be on the safe side one should follow the same for the old gears in case the pattern has changed just a little.

Well guess that is enough for now. I am going to start a new thread and post some pics of the numbers on the new Ford axle i bought and see if number dummy can verify that the axle is in fact a OEM ford axle. It was well packed and was in a original Ford box with the label where it was sent to a ford dealer. I just want to try to verify that it is not a aftermarket shaft thrown in the box. I can tell it is old because it has some areas with very light tiny specs of surface rust. All 5 studs look like they have never had a lug nut on them. 1 of the lug nuts in fact is not quite pulled all the way up tight against the back of the axle. I fit had been installed at one point, I believe it might have pulled the stud in flush.

Another clue that makes me think it is in fact a oem ford axle is that the part numbers are case into the end of the outer hub, they are not stamped numbers. I don't know if aftermarket shafts have the part numbers cast into them or if they are stamped.

When you get a chance to look at yours, see where the numbers are and how they were made if you don't mind.
Another thing I noticed is that the shaft has the little rubber O-ring on the end of the spline. It is orange colored and rotted into.. If it had been used then I think it would show sings of oil or something..

 

I don't have the original axles any longer, those are long gone

 

Well thanks anyway. After searching for pics of axle shafts it appears that this is a Ford axle. The way the center ring of the axle is made seems to be constant with Ford. Most all others are machined on the face and have name tags on the front.

 

Update. The instillation of the new updated spider gear kit did require spreading the side gears in order to get the other two gears to roll in the housing. We could roll one in but not both, it was just too tight. We did not have the tool and did not have to fabricate a tool like the one in the pic above though it would have been easier. What we did was to put the axle shafts in and slide them in through the side gears. We installed the C-clips and then used a pry bar behind the axle flange to pull pressure outward on the shafts. That also pulled outwards on the side gears compressing the new wavy style thrust washers against the differential housing giving us enough room to install the other two gears. It was defiantly a two person job and a third hand would have been even better.