Front 3rd member and Dana 50 stub shaft install...(56k warning)

Andy351 · Feb 10, 2004

1. Chock the wheels, jack up the front, remove the tires and support it with SAFE jackstands.
2. Remove the calipers (C-clamp to compress the pistons in the caliper, use a hammer and screwdriver to tap out the clips that hold the caliper in place.)
NOTE: if you’re already lost, stop here. Put it all back together and take it to a competent shop.
3. Remove the hubs. My hub write up.
4. Remove the spindle nut. Instructions can be found in Big Mikes wheel bearing write up. (The spindles on my 89 use a single combination spindle nut/bearing adjuster. SEE PICS BELOW:

*The 4 prong spanner socket for the spindle nut:

5. With the rotor and wheel bearings removed, the next step is to remove the spindle. Remove the 5 or 6 bolts holding on the spindle, and pull it off. (It may need some gentle tapping to break it free.)

6. With the spindles off the axle shafts slide right out. On the passenger side, you will need to undo the clamps holding the slip-shaft dust cover on; if you don’t you will have a very hard time pulling the shaft out.

7. Now that the axle shafts are out, undo the bolts holding the drive shaft onto the pinion yoke. Also, pull the front diff breather off.
8. At this point, all that is holding on the 3rd member is the front cover bolts and the 2 bolts that attach from the side. Undo the bolts on the side first:

9. Now start removing the front cover bolts, starting with the bottom ones. Leaving the top 2 attached but loose will allow you to drain the housing before taking it off.
10. Once it’s drained, remove the last bolts holding it on. Careful, its pretty heavy. I just let mine drop since I will never be using it again, but you may want to place some rug or similar soft item underneath it to break the impact.
11. Scrape off all the old silicone gasket and use silicone gasket maker to form a new gasket.
12. You are all ready to attach this:

13. Installation is basically the reverse of removal. One way to make the install of the 3rd member go easier is to get 2 studs that thread into the cover bolt holes on the 3rd member itself; these will act as a guide and make it much easier to install the bolts. I torqued the cover bolts and side bolts to 60ft/lbs.
If you're doing the c-clip elimination trick or the Dana 50 stub shaft, read the next post.
14. Reinstall the axle shafts, make sure you put the dust cover back over the slip shaft.
15. If your bearings need it, replace or repack them.
16. Torque the spindle bolts to 60ft/lbs
17. Reinstall the rotors, wheel bearings, and spindle nut/bearing adjuster. Torque the spindle nut to 50ft/lbs while spinning the hubs around to seat the bearings. Then back the nut off 90 degrees and retorque to 15-20ft/lbs.
18. Reinstall the hubs, calipers, and tires.
19. Fill the front diff with fluid, should take about 2 quarts. (i used valvoline 80w90)
20. DONE.

Andy351 · Feb 10, 2004

Some F-250s and early F-350's came with a Dana 50 TTB. There is no easy way to determine which truck had this, but if it’s a TTB truck with Dana 60 sized hubs, then it has the Dana 50 version of the TTB. The Dana 50 is very similar to a Dana 44; it uses a 9” ring gear as opposed to the 8.5” Dana 44 ring gear and Dana 60 sized hubs and outers (gurus: am i right?), but it still uses the same size/spline inner axle shafts. The advantage in this is that the center u-joint (stub shaft) is much larger on a Dana 50 TTB.

The Dana 50 version obviously has larger ears and the u-joint is a drive shaft stlye 1310. (the guy at the yard said 1350, but it didn’t look that big to me :shrug) It also uses full circle retainers as opposed to the c-clips that the 5-297x Spicer joint uses. This method of retention is much more durable.

A major issue with the TTB 3rd member is that it uses a c-clip to retain the axle shaft. The only way to change a shaft in the field is to remove the entire 3rd member, which = messy and time consuming. Where the c-clip attaches on the Dana 50 shaft is thicker than the Dana 44 version and will hit the spider gear cross pin before you can get the c-clip to engage.

The common way to fix this problem is a spring in the cup of the slip shaft. (this method is also used for a locked front end, and can be used with a stock Dana 44 stub shaft as well)

The spring will provide pressure, pushing the 2 passenger inner axles apart and keeping the stub shaft secure in the housing. I used a 7/8” compression spring from OSH, cut down to about 2½”. You may have to play around with the length of the spring before you are comfortable. Make sure you install the complete passenger side axle shaft and spindle. This will give you an idea as to how much play the spring allows.

Slide the stub shaft into the housing:

About this time, if you haven’t already done so, you will want to chop off the stupid nipples on the frame that catch your knuckles:

Now, since the Dana 50 ears are larger, you will want to rotate the stub shaft to see if you need to grind the beam down a little for clearance.

Mine was fine, so once I got the spring length dialed in i was pretty much done.

FROM HERE, REFER BACK TO STEP 14 OF THE PREVIOUS POST.

Tvanleeuwen · Aug 3, 2007

Is the axle shaft that slides into the slip shaft the same on the D50 and the D44? When I do this uprade, do I use the long axle from my D44 or the D50? Can I use the D50 long axle shaft? Is it any stronger? Thanks.

Shadofax · Feb 10, 2004

Nice writup Andy. :thumbup

Two items, did you tack weld the cup on the of the slipshaft? otherwise your spring will pop it out. I agree you have to play with the proper spring length, I used quite a bit less spring due to the cap pop issue. The spring does not really have to apply any force, it's really just there to make sure the shaft won't back out of the differential, so you really just need enough spring so there is no movement of the axleshaft.

The guy at the Jyard I think is right, not a 1310, but a 1350 as I recall. Would have to go look in spicers books, but the part number for the ujoint is a 799X.

Andy351 · Feb 10, 2004

thejuice said:
Two items, did you tack weld the cup on the of the slipshaft? otherwise your spring will pop it out.

i'm working on the tack weld thing. probably this weekend.

Andy351 · Feb 11, 2004

84brownbronco said:
now tell me that you drilled and tapped a hole in the bottom of the new 3rd member so that draining fluid is a breeze??

:brownbag:

dblue351 · Feb 11, 2004

Good shit!

You can also use a valve spring in there. Thats what I used back in the day.

Andy351 · Feb 11, 2004

84brownbronco said:
WHY WHY WHY WHY????????? now you cant change the fluid in a flash. you gotta suck it out. which is a bitch and you dont always get it all.

because i really am lazy. doing this writeup has spent all my energy for the next month. i'll probably do it the next time i change fluid, which will probably be after the summer or so.

Andy351 · Feb 11, 2004

dblue351 said:
You can also use a valve spring in there. Thats what I used back in the day.

believe it or not, all the shitty machine shops and junkyards i tried were like "we can order one, but we don't have one here."

i forgot about the spring until the 3rd was going in at like 4:00 saturday afternoon, so i just got the spring from OSH. it was like a dollar, and my friend owed me money anyway, so technically it was free. the D50 stub shaft was free too. the guy at the yard i went to was like, "you can do that? cool, take it" so i was stoked.

Shadofax · Feb 11, 2004

Andy351 said:
believe it or not, all the shitty machine shops and junkyards i tried were like "we can order one, but we don't have one here."

i forgot about the spring until the 3rd was going in at like 4:00 saturday afternoon, so i just got the spring from OSH. it was like a dollar, and my friend owed me money anyway, so technically it was free. the D50 stub shaft was free too. the guy at the yard i went to was like, "you can do that? cool, take it" so i was stoked.

Andy, you don't want a valve spring in there anyway. As Dave said, it was "back in the day" after lots of folks doing this and having lots of trouble with the stupid cap popping, a valve spring is way too loaded. your spring you have is the new ideal. And i can tell you the shop I deal with uses the same spring you showed, same spring I have had no problem with (if cut to proper size) for about a year now. this spring works well because a valve spring is all about pressure in this scenario, when really you just need a bit of push to keep the shaft where it belongs. Remember, the differential will not exert a force pushing the axleshaft out. The ring/pinion move the case splines which contact the axleshaft at a direct angle (i.e. no worm type gear), so the force in the diff does not push the axleshaft out. it can move out on it's own, but not if there is a small amount of resistance.

Shadofax · Feb 11, 2004

85f150 said:
i know i am stupid, but i still confuzed.....how does the spring stay in between the two axle shafts and waht is the point of doing this...please don't bash to hard, even though it won't matter :cry

The question isn't stupid. maybe a couple pics will help:

OK, first pic just shows the D50 slipshaft back installed under truck. Note the rubber boot. Second pic...where the rubber boot is...there is a joining of the inner D50 shaft, and the passenger long inner splined shaft that goes out to the wheel (and the shortshaft). So , the spring goes into this tube, then you slide that long passenger splined shaft in. So, the spring stays in that axle/yoke tube and provides some push on the D50 slipshaft that goes into the differential, as well as against the shaft that goes on out to the wheel. If you didn't have this spring, the inner D50 slipshaft can back it's way partly or mostly out of the differential. If is loses enough contact spline within the diff. it will strip and likely break, or the shaft will fall out, equally bad.

If you want more pics on just this D50 slipshaft and spring stuff, go here:

http://2bigbroncosnorthwest.superford.org/registry/vehicles/detail.php?id=628&s=13090#content

Andy351 · Feb 11, 2004

ya, the basic idea is that you are using the spring to push the 2 axles apart

heres a real simple diagram, the C is the cup where the spring sits in, and the ------ is the passenger side inner shaft

C--------

the spring goes inside the C and pushes on both the C and the -------, keeping the stub shaft from walking out of the housing.

reptillikus · Feb 12, 2004

Very good writeup andy! :thumbup
Its appears it actually alot easier to do than i thought!

Oh, on a side note, you can still drill and tap that 3rd member without remvoing it, its just a little harder. I did mine laying on stones in my driveway :brownbag

broncoguy90 · Apr 9, 2004

sp using the spring idea....your getting rid of the c clip and when you install the spring when 4wd is engage it pushes the axles shafts in the front pig? i have a track-lok up front and im still confused on what to do...lol

Shadofax · Apr 9, 2004

It doesn't matter what carrier you have up front....track lock, ARB, open, whatever.

If you want to remove the c clip (which HAS to be done for carriers with lockers, but that is another issue), open up the diff and take it out. Now, what is going to hold your passenger side axle inside the diff, since it has a slipshaft out where that boot is? There is nothing to hold that inner shaft in place, so it will work it's way out of the diff and cause you lots of problems. They way to solve this is by putting a spring inside that boot (where the slipshaft is). As Andy mentioned, this puts pressure back on that inner shaft that goes into your diff, so it will not come out.

Just as a side note, inside the diff. (or pig as you say) the axleshaft end has splines that contact the diff. carrier for engagement. This spline contact is not like a worm gear, but rather direct engagement, so the axleshaft is not really pushed out by the diff., so it only takes that spring out inside the boot/slipshaft to keep the spline engagment inside the diff.

Shadofax · Apr 10, 2004

TRUCKY18 said:
i know this thread is kinda old but any way. what are the advantages of going to the 50's 3rd member? accept for the larger U-joint?

No advantage at all to putting in the D50 inner slipshaft, which is just an axleshaft and yoke.

The shaft is 30 spline like the 44, necks down, yada yada. But, where most breakage occurs, if not out at the 19 spline outer short shafts, is right here....that hard to get at inner slipshaft/ujoint/yoke assembly. Not in the axleshaft for the most part, but in the yoke/ujoint. Well, swapping from a 1310 series 760x spicer joint (what, you don't at least have that?) to a 1350 series (799x spicer) joint, and accompanying big yoke and external snap rings (like on a driveshaft), should tell ya why.

External rings are better at retaining the ujoints, probably why they use them in driveshafts.

I believe a link I provided showed the difference here. So now, for me, the plan is to just carry a spare outer 19 spline shaft, 760x joint, and I hopefully have an easier fix. (I do carry my old D44 slipshaft, but doubt that D50 piece will ever break before the outers), see, it makes life much easier in replacing an outer shaft/joint if needed.

Dustball · Apr 11, 2004

TRUCKY18 said:
i know this thread is kinda old but any way. what are the advantages of going to the 50's 3rd member? accept for the larger U-joint?

There is no advantage of the D50 diff. The advantage comes from the D50 inner slip yoke but that can be used with a D44, no probs.

p-351 · Feb 12, 2007

There is an advantage to the D50---the availability of 4.30s! Just too bad I found out about this after I did the 4.10s:doh0715: (I didn't want to to to 4.56s with only 33s.)

I was searching for D50 stub shaft stuff when I came across this thread, so I thought I'd revive it.

Andy351 · Apr 12, 2004

i didn't use a D50 unit anyway. i got a D44 3rd.

montster · Apr 13, 2004

would the d50 3rd bolt up to the d44?

Andy351 · Apr 13, 2004

yes, but it uses a different ring and pinion and carrier. theres no point tho, unless you can't find a D44 at all because its not any stronger. the only thing that is better is the stub shaft from the D50 and that will fit in the D44 3rd anyway.

BadNews · Apr 9, 2017

If I understand this correctly, the D50 unit uses a 9" ring gear instead of 8,5". Wont the 9" be superior in strenght?
I'm replacing the ring, pinion and differential.

Shadofax · Jul 12, 2005

stangmata50l said:
Sorry to revive such an old thread...

Can someone explain this alittle better about the "stupid cap popping".

If the valve spring is way too loaded, could it be cut down a bit to work better? I'd like to grasp a better understanding on this (plus i have a messload of valve springs in my garage).

At the end of the slipshaft, the female end has a press fit cap right at the yoke/ujoint. So, when you put a spring in there to lightly load the slipshaft to outer axleshaft, if you use too long a spring, or one with too much tension, it will pop that cap it rests against. You usually lose the spring and cap on the trail at that point. You may not know this has happended until the next time looking under there. You can tack weld the cap.

Don't use a valve spring (yes, they are always cut down). Too stiff. ARB and likely other locker suppliers have a light spring available to cut down. It's about $3 from most small 4x4 shops.

Crazedatwork · Jul 12, 2005

Mark, that spring ended up too short for Todds application, so we used a peice of heater hose.

Crazedatwork · Jul 12, 2005

Worked great this last weekend wheelin...just enough pressure on the outer, that it pushes it out to the spindle, and keeps the inner in the diff.

Shadofax · Jul 14, 2005

Pony-boy said:
Since we revived this post.
Don't be a dumb chit like me and go thru all the trouble of tapping a hole
for the drain plug, installing the plug, installing the diff, and 2 weeks later
remembering that you forgot to grind a notch out of the TTB to take the plug out

Yeah, I was pissed

?? :shrug Not sure I follow ya.

You drilled a drain hole in the 3rd member, but too far forward? so the TTB stamped piece is in the way?

Want my properly drilled 3rd?

Pony-boy · Jul 15, 2005

If it comes with the ARB :thumbup

I have another third member if I want to do that.
I just needed to grind the lip back a little.

Bob and I drilled and tapped it without thinking
of the clearance :toothless :histerica

GIVE 2 ******** A DRILL. BAD IDEA :slap

taftmarley · Jul 15, 2005

I just want to be sure I understand this wright. :shrug

Have an 88 with the TTB with the BS tophat locking hubs.

My understanding is this; I can use the D50 axleshaft and replace them with my 44 shafts and keep the 44 3rd member.
Now would I need to use the spendel out from the D50?
The reson I ask is I want to get reid of the tophats hubs so I can have real hubs. Later date I i'm planning on a SAS (long way down the road) but this sounds like a easy and cheap way to get the better hubs and joints.
Thank for any help Todd.

Crazed · Jul 16, 2005

taftmarley said:
I just want to be sure I understand this wright. :shrug

Have an 88 with the TTB with the BS tophat locking hubs.

My understanding is this; I can use the D50 axleshaft and replace them with my 44 shafts and keep the 44 3rd member.
Now would I need to use the spendel out from the D50?
The reson I ask is I want to get reid of the tophats hubs so I can have real hubs. Later date I i'm planning on a SAS (long way down the road) but this sounds like a easy and cheap way to get the better hubs and joints.
Thank for any help Todd.

The change to D50 slip shaft dosent have anything to do with the hubs..

Front 3rd member and Dana 50 stub shaft install...(56k warning)

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