Probably pretty preposterous van project

[moparman76_69]

So I haven't had much time to get much done, instead of a mad rush to finish it in time for SDAC and possibly over looking something I decided to focus on finding a house and finishing this on my on pace. With that said I did get the diff part done, it only needs the bolts grinded down so it won't hit what I assume is 4th gear that sticks out into the pinion area. I'll be posting the steps to getting the AWD to fit in my next post. I had an issue with the clutch but it showed up today. I'll get pics of that and the other parts that made up my christmas in May later.

[moparman76_69]

Ok so how to make a AWD diff fit your 523. I'm sure the process is similar for a 520 but I can't confirm this.

First let me start by saying this was much easier than I expected. I assumed this would be one of the harder parts of the project but it was all pretty much straightforward.

Here are the two diffs side by side.



The 523 is on the left and the AWD is on the right. Here is more detail on the pass. side bearing.



The AWD uses a different bearing because the diff housing is larger and is splined to accommodate the PTU. Here is a better shot of just the AWD diff.



You need to use the pass. side bearing housing off of the 41AE the diff came out of so that A) the bearing will fit and B) the PTU will bolt up.



As you can see the top right bolt that the extension housing uses will line up, the others need to be drilled and tapped for M8x1.25 threads. Be careful as you will drill through the upper diff housing bolt hole with the top left, and each one of the lower holes will drill through the lower diff housing bolt hole. You'll have to use shorter bolts than what the extension housing uses. Remember that the case is aluminum so it will strip out easily.



One that is done all you need to do is put the 523 ring gear on the AWD diff. To do this you will need to flip the gear over and mount it to the opposite side of the diff than the stock AWD ring gear uses.

I unfortunately don't have many pictures of this but I'll explain as best as possible. The 523 ring gear's flange is offset. The "inside" of the ring gear flange usually bolts to the drivers side of the diff flange, the ring gear is threaded. The AWD diff and ring gear have a different offset so they won't readily interchange. If you flip the 523 ring gear and bolt the "inside" flange that originally mated to the drivers side, onto the passenger side of the AWD diff, this will get you almost perfectly back to the stock ring gear location.

If you mount the diff in the trans this way you'll notice two things, first is the ring gear doesn't sit exactly where it did with the original diff. I made a mark on the case before removing the diff, and again with the ring gear bolted to the AWD diff and it was "around" .035 off. I say "around" because others measured it as .030 and I was using a rather unscientific method (dial calipers and two sharpie lines). I decided to go with .030 as I figured that other people probably did a less ghetto measuring job and if it was a couple thousandths off it wouldn't wear the gear too badly. I ended up finding a transmission shop that took care of the machining, and in my excitement to remount the ring gear I didn't take pics of the machined surface. Put loctite on the bolts and torque them to spec, and you'll end up with this



The other thing you'll notice is that the ring gear bolt heads, which now stick out the drivers side of the diff, hit the gear that slightly protrudes into the pinion area. The only answer is to remove enough material off the bolt heads to clear. I haven't done this step yet but it is pretty straightforward.

After the diff is in then you can bolt the diff housing and etc. back up.

REMEMBER, this is just a guide, YMMV. I accept no responsibility for what you do to your vehicle.

[turbovanman²]

Great post, thanks.

[Clay]

you could always use flat head allen bolts and cut a countersink into the diff.

The other thing you'll notice is that the ring gear bolt heads, which now stick out the drivers side of the diff, hit the gear that slightly protrudes into the pinion area. The only answer is to remove enough material off the bolt heads to clear. I haven't done this step yet but it is pretty straightforward.

[moparman76_69]

I thought about that but I'm not sure what strength the bolts need to hold up. There is also a neck on the current bolts and a countersink of sorts which I assume is there to help locate the ring gear, I'll get a pic of the current bolt to show what I mean.

In other news, an '01 axle is 1" to wide to fit in the older van. Looks like I'm stuck using the 93 axle. Good news is the hub to axle pattern is the same except for one bolt so it looks like I can use the '01 disc brake setup at least.

[Reaper1]

Eh...1"....use a sawzawll!!

[135sohc]

I thought about that but I'm not sure what strength the bolts need to hold up. There is also a neck on the current bolts and a countersink of sorts which I assume is there to help locate the ring gear, I'll get a pic of the current bolt to show what I mean.

In other news, an '01 axle is 1" to wide to fit in the older van. Looks like I'm stuck using the 93 axle. Good news is the hub to axle pattern is the same except for one bolt so it looks like I can use the '01 disc brake setup at least.

If the ring gear still has a bit of a press fit onto the carrier it should be as centered as its ever going to be. But I do also agree on keeping the current bolts if you can. That neck is kind of tapered to act as a tapered pin because the bolt holes through the carrier are oversized and not precision reamed so even if you can get them very tight and loctited. If there was enough torsional twist it could snap a regular bolt off.

[RoadWarrior222]

Eh...1"....use a sawzawll!!

I are guessing he means between the outer and inner flanges, since if it was just on the splined ends he might have considered trimming it.

[Reaper1]

I actually figured the same thing. I was joking around....although it *could* be done.

[moparman76_69]

Eh...1"....use a sawzawll!!

The thought crossed my mind....

If the ring gear still has a bit of a press fit onto the carrier it should be as centered as its ever going to be. But I do also agree on keeping the current bolts if you can. That neck is kind of tapered to act as a tapered pin because the bolt holes through the carrier are oversized and not precision reamed so even if you can get them very tight and loctited. If there was enough torsional twist it could snap a regular bolt off.

With having to switch the ring gear to the other side of the flange there is no ring to center it. With all the bolts ran down there is a very small amount of play, almost none at all. I used red loctite and torqued them per the FSM.

I are guessing he means between the outer and inner flanges, since if it was just on the splined ends he might have considered trimming it.

Yeah It'll be easier to make the rear disc work on the other axle than to shorten the beam. It could be done but not really worth all the effort.

[RoadWarrior222]

Theory-etically... if it are the tube type axle (Passenger side, long one) one could do it very neat by determining where it are welded into the end of the tube, grinding that off, shortening the tube and welding it back in...

[moparman76_69]

So I dropped the axle out again. The '01 AWD hub/brake assemblies bolt onto the 93 axle with ease. I'm trying to get it all back on its wheels to move it to the new house so I can get it finished in time for Monster Mopar in September.

[moparman76_69]

60 hour work weeks suck. Slowly working on moving stuff from one garage to another. I'm going to go ahead and mount the rear diff and put the rear CVs in before I move it so that will be done, hopefully this week. If I hustle I can get it done by labor day, if not should be done by Monster Mopar Weekend in Indy.

[turbovanman²]

So I dropped the axle out again. The '01 AWD hub/brake assemblies bolt onto the 93 axle with ease. I'm trying to get it all back on its wheels to move it to the new house so I can get it finished in time for Monster Mopar in September.

Memory sucks, so your using a stock FWD rear axle and the 01 stuff bolts right on? If so, damn cool.

[Vigo]

Im pretty sure he means an awd 93 axle.

[moparman76_69]

Im pretty sure he means an awd 93 axle.

correct. You can use the '01 AWD disc hardware on the 93 AWD axle beam.

[moparman76_69]

Progress!!!

So I got the 93 AWD axle w/01 disc hardware actually installed and the wheels back on a couple weeks ago. Also pulled the harness out of the engine bay.



Also installed the tag since the old one expired.



Then the fuel pump went out on one truck, then the other truck started leaking fuel. After having to get new fuel pump hanger assemblies out of the yard for both, I finally had the space in the garage to move it.



Pressure washed the engine bay at a car wash on the way home and got it nestled in the garage.



So there it sits and hopefully I can get motivated to get back on it. With a return to 6 day work weeks and 10+ hour days, it will be slow going.

[Clay]

Done yet?

[turbovanman²]

Love those wheels,

[moparman76_69]

So after a couple of days in the garage I found this.





Apparently it's like introducing a new animal into the house as now both trucks and the wife's car are leaking fluids.

I am currently working on getting the turbo drain and oil pan baffles done. I'll post pics later.