Front Diff and AWD questions (missing shafts)

[avgMounty]

It turns out my AWD purchase is not AWD.
The front drive shaft and both CV axles were removed, probably by the owner before the guy I got it from. I didn't check it all that well. Oopsie.. I assume it was done to gain 1 mpg or whatever.

Is the front differential sealed without the axles in? Or am I going to have to pull and rebuild it?

Other than that, it looks fairly simple to replace the axles and drive shaft. I am sure I'll be missing some other bits and pieces that I'll have to figure out when I get in there.

 

[V8]

I strongly recommend that you open up the front diff and clean and inspect everything. The Dana 35 front is not a particularly sturdy unit, and mine failed at around the 150K mark. I ended up having to replace everything.

 

[wollimann]

Is the front differential sealed without the axles in?

No, maybe the inner parts of the axle shafts be still in there or it's plugged with other parts?

The other question is why all these parts are missing, maybe the AWD transfer case
has an issue. If so that could be the much more expensive part of the story.
Hope that it is "only" a front differential problem.
Yes, changing parts at the front -> differential 3 bolts, shaft and axles is not a
big deal. Rebuild the differential will be more challenging/time consuming/sometimes frustrating.
Good luck for your AWD project, get some good spare parts and find out the reason.

 

[amj441]

No, maybe the inner parts of the axle shafts be still in there or it's plugged with other parts?

The other question is why all these parts are missing, maybe the AWD transfer case
has an issue. If so that could be the much more expensive part of the story.
Hope that it is "only" a front differential problem.
Yes, changing parts at the front -> differential 3 bolts, shaft and axles is not a
big deal. Rebuild the differential will be more challenging/time consuming/sometimes frustrating.
Good luck for your AWD project, get some good spare parts and find out the reason.

I agree with wollimann, if the ends of the CV axles are still plugging the holes in the differential then it should be OK, otherwise it would be wise to replace/rebuild/inspect it.

Hes also right if the AWD unit has issues with its viscous coupler and binding then you may have to look into replacing the AWD unit.

 

[avgMounty]

Thanks for the bad news, guys. Every time I try to be positive...

I was also wondering if the parts were removed because the transfer case and/or the differential were bad, but figured I'd ask here just in case it was a "no big deal" type of thing. I planned on pulling the differential when I got to fixing a few other things in the engine bay (hopefully this weekend). I will update with info and pics when I get that done. I have a feeling it's seen some water if it's not sealed.

Is there a way to test if the AWD transfer case is good as it sits? Or is it easiest to just replace all the missing parts and test drive it?
I've considered manual transmission and manual transfer case swapping it... which is a lot of extra work, I know. If repairing the stock unit (or getting a second rebuilt one) isn't too expensive comparatively, then I'd be fine with leaving the truck stock also. I guess converting it to RWD would also be a viable option. Everything is paved asphalt here, and flat. It's not like I need AWD or 4X4. I don't know what would be the easiest way to do that. Probably a 2WD trans swap, rear shaft, and different front hubs/bearings?

I am trying to get as much cleaned up now before I start daily driving it so that there are fewer potential surprises later on, so I'm not in a huge rush yet, but I'd also like to get stuff done as correctly and reliably as possible.

 

[410Fortune]

The Dana 35 sla front diff is plentiful
It was used in the 4.0 ranger till 2011
No need to ever rebuild one, just swap it
You will need awd / 4wd wheel bearings cv axles and a diff 5.0 trucks are 3.73 ring and pinion

The only way one of these diffs fails at 150k is if it was struggling like mis matched tires or inflated issues (rolling diameter)
I see 250k miles from these diffs on the regular
I sell them for $50-200 depending on miles and gears

All torsion spring trucks, even rwd, have the provisions for the front differential

The 4406 transfer case conversion is well worth it, it saves power fuel milage and wear and tear on tires bearing axles

I never put the awd back on the road
I always convert them to 4wd

 

[amj441]

The Dana 35 sla front diff is plentiful
No need to ever rebuild one, just swap it
diff 5.0 trucks are 3.73 ring and pinion

The 4406 transfer case conversion is well worth it, it saves power fuel milage and wear and tear on tires bearing axles

I never put the awd back on the road
I always convert them to 4wd

Honestly agree. worst case scenario you just swap the AWD unit out and just put the used transfer case in and leave it in 2wd. just leave everything else disconnected and replace as needed/purchased and sourced. Inspect your differential and see if the gears are any good, if not just unbolt it until you find a replacement.

All I have ever heard is bad things about the AWD units, you might as well swap.

MAKE SURE YOU HAVE CV AXLE ENDS BOLTED INTO YOUR WHEEL BEARING. THE AXLES ARE NEEDED FOR PROPER PRE-LOAD. I personally have a 2wd id like to 4wd swap eventually and I run the 4wd hubs with an axle nub like Wolliman posted to provide the preload. The full cv axle is not needed but at least the nub IS.

 

[410Fortune]

Yes and 2wd knuckles have no holes for cv axles so easy to tell if your truck was originally rwd and somebody installed a awd trans and t case or the other way around

The 96-97 trucks have the speed sensor in the transfer case
98-01 do not
So Many times I have seen people trade their 96 awd case in for the core charge only to get a non speed sensor case and then you are screwed. You can actually separate the case halves and install the speed sensor bits onto the low mile new case
I usually try to use the 2000-01 case if possible when I am asked to repair these

A well maintained awd setup is good! Fluid changes proper tire rolling diameter they can take some serious abuse
But they are also a wet clutch inside and the power distribution is basically 70/30 anything that is not used generates heat as wasted energy
Why I 4406 all our family and friend rigs
A true 2wd 4hi and 4 low t case turns these things into a real truck 3/4 ton drivetrain in a 4500# suv is overkill
Yes the 302 the 4r70w and the 4406 t case were used in f150 and f250 expeditions under 5800# curb weight so it is a 3/4 ton drivetrain

 

[avgMounty]

Thanks for the additional information. I'll report back when I get it pulled apart to see if the CV axle nubs are present (which it sounds like they kind of have to be). Hopefully they're in the diff too. If not, I'll probably reach out to you @410Fortune

I know the AWD stuff is weaker and more failure prone, but I drive like an old lady at this point and there's not even a dirt road for me to drive on, so it's not like it'll get any abuse at all. That's also why I don't mind going to 2WD if it's easier/cheaper. I'll re-read the 4406 swap at dinner. Maybe it'll be motivational.

Anyways, I have to drop off the stock wheels to get tires soon. I am going with the original size. Until then, it's sitting on the spare set of 20" dubs it came with. I should have checked for the CV nubs when I was doing the pads and rotors.

 

[410Fortune]

Is there a big 32mm nit and cotter pin behind your center caps?
If so those are the cv outers
I not then you have rwd front wheel bearings and likely knuckles

 

[V8]

The Dana 35 sla front diff is plentiful
It was used in the 4.0 ranger till 2011
No need to ever rebuild one, just swap it
You will need awd / 4wd wheel bearings cv axles and a diff 5.0 trucks are 3.73 ring and pinion

The only way one of these diffs fails at 150k is if it was struggling like mis matched tires or inflated issues (rolling diameter)
I see 250k miles from these diffs on the regular
I sell them for $50-200 depending on miles and gears

All torsion spring trucks, even rwd, have the provisions for the front differential

The 4406 transfer case conversion is well worth it, it saves power fuel milage and wear and tear on tires bearing axles

I never put the awd back on the road
I always convert them to 4wd

Nope. I suspect the pinion seal went out. The diff really didn't look like it was oil starved, but it grenaded. The truck has always gotten tires replaced in full sets, and I check tire pressures regularly. So, I blame it on the pinion seal. My replacement diff came from a junkyard that broke down a really low mile. 20K miles '01 Explorer many years ago and sold everything except for the front diff. I got the deal of a lifetime for it and learned that it really can pay to shop around if time permits.

How difficult is it to convert to 4WD? The last time I looked into it the conversion seemed really complicated.

 

[410Fortune]

Can be done over a weekend
Find bw4406 manual t case and linkage
The most complex part is getting drivelines that fit
Cutting hole in the floor for shifter
And hooking up the lights in the dash

Can take it a step further and convert to a 4406 e shift.. this is way more involved but I have done several times. For this a dash switch and motorolla stand alone 4wd control module is added as well as the wiring harness to feed the transfer case mounted shift motor
Covered in great detail on this forum
I converted my personal 96 explorer to 4wd many years ago


410fortune goes low range..

410Fortune 96 AWD Ex - goes low range

I picked up my transfer case last night. Two t cases were included in the deal, one is strictly for parts. The t case I will be using in my 96 5.0L AWD explorer is a 2001 F-150 BW 4406 manual shift :) this makes me very happy. I will no longer have full time AWD, instead I will have 2wd, 4hi...

www.explorerforum.com

that was my first time. I have not built another awd truck unless requested (twice, one was for ice racing, the other my stepson too
Lazy to do the conversion and gather the parts so his sport trac remained awd)

 

[avgMounty]

Yes, there are visible 32mm nuts. No cotter pins. No CV parts stuffed in the diff tubes, but I don't think that's the problem anyways.

I'm not sure if this makes me more or less worried about the AWD transfer case.

 

[410Fortune]

yes 4wd delete lol

how was the fluid in t case?

 

[avgMounty]

Oh, definitely an oil leak somewhere on the back of the motor. Hoping it's not the rear main seal. I'll try and get a better look at it next weekend. When I do the fan, belt, tensioner, etc.

If I can verify that it's probably coming from the rear main seal... I'll lean real heavy towards M5OD-R2 and manual BW4406 swap before I bother registering it.

yes 4wd delete lol

how was the fluid in t case?

Didn't pull the transfer case, or even look at it.

Going to try and get tires this week. I'll take a peek at it when I slap those on. Obviously not in a huge rush now.

 

[410Fortune]

Just drain the t case fluid see if is red or black or?

5.0 either valve covers or rear main
The cat converter being directly under the rms did not help

 

[avgMounty]

Yeah, I'll get to it this weekend hopefully. Ran out of time yesterday.

 

[Turdle]

Along with valve covers, Rear of intake can, but rarely, leak oil, also the pcv grommet on rear center engine block could mimick a main seal leak

 

[V8]

Yes, there are visible 32mm nuts. No cotter pins. No CV parts stuffed in the diff tubes, but I don't think that's the problem anyways.

I'm not sure if this makes me more or less worried about the AWD transfer case.

View attachment 462784

Looks familiar. My transfer case was fine, and remains so to this day. I was told after I bought it that the transfer case wouldn't make it to 100K. I'm at 240K right now and haven't exactly babied the truck, especially after discovering it really comes to life past 3500 rpm

 

[avgMounty]

I didn't get to work on the Mounty yesterday. I had to work on the Mustang. I fixed three things, but it's still broken. I probably won't get to it next weekend either. (I usually work 6 days a week, and I rehab cats.)

Looks familiar. My transfer case was fine, and remains so to this day. I was told after I bought it that the transfer case wouldn't make it to 100K. I'm at 240K right now and haven't exactly babied the truck, especially after discovering it really comes to life pas 3500 rpm

I am currently leaning towards getting a replacement diff and replacement drive shaft and CV axles. I'll see what's at the junkyard this weekend since the Mustang (current daily driver) needs and unbuyable part too. I'm hoping the t/c is fine like yours. Leaving a daily stock really makes things easier.