1980 F350 4X4 C6 Project

[Gary Lewis]

If I was picking I'd pick the 1345 over the 208 and the 1356.  It is supposedly a bit stronger than the 208, doesn't have the oil pump problem of the 1356, and has a slightly lower gear ratio than the other two.

[Atlas75]

One other thing I noticed while under the truck.  Should the driveshaft turn with equal resistance in both directions?  Mine did not.  It turned much easier counter clockwise.  After I removed the driveshaft I turned the rear yoke and it turned with equal resistance.  I’m guessing the yoke on the t-case will spin easier counter clockwise.  Is this normal?

[Gary Lewis]

I've not experienced a transfer case spinning easier in one direction that the other.  But the rear axle will if the brake shoes are lightly touching.  Because one shoe is self-energizing, meaning if it touches it'll get pulled against the drum, they can spin easier one way than the other.

[Atlas75]

The brakes on the rear axel example makes sense and thankfully mine spins with equal resistance in both directions.  I haven’t actually spun the T-case yoke yet but I will before I put the driveshaft back in.  I guess it’s possible given how tight the one u-joint was that it could be binding more in one direction vs. the other.  We’ll find out tomorrow.

[Atlas75]

My t-case does indeed turn with less resistance one way vs. the other.  I’ll see if I can find out more about that phenomenon and report back.  I did manage to remove the grease from the tag while under the truck today.

1345 it is!

[Atlas75]

New U-joints are installed!!  I had a helper today and I’m glad I did.  It made things just that much easier.


Like the driveshaft removal the U-joint at the rear axel fought back again today.  We started with just the press and that did not work.  We added heat and that did not work either.  We were getting pretty frustrated and then I remembered a bar I made for just such an occasion.

We gave the press another rotation or so and reapplied the heat.  Finally it popped loose.  I think it startled my daughter a bit as it was kinda loud!

After that it was just the mundane process of replacement of a U-joint.  They were a little tighter than I would like to see them but no tighter than the originals.  So back under the truck I went and reinstalled the driveshaft.



After everything was reinstalled, I started the truck and ran it in drive (with the tires removed) up to 45 ish mph.  It was pretty still.  No vibration to speak of.  I think between the U-joints and the tires/balancing we should have the vibration issue licked.

Now…while I was running it in drive I would apply the brake and then wait for the rear axel to stop and then shift into park.  I noticed a clunking noise a few times so I enlisted the assistance of my other daughter who is 6.  I had her watch the passenger side rear drum for me.  I put it into drive and let it spin.  I asked her if it was spinning and she said yes (which it should have been).  Then I pressed the brake fairly hard and I saw the drivers rear stop fairly quickly.  I asked if her’s had stopped and she said no, it was still spinning!  Clearly the passenger rear has some issue.  Maybe it just needs an adjustment? Beyond that I’m guessing I’ll need to remove the axel and drum to see what is allowing it to continue to spin with the brake pressed pretty hard.

I’ve never had one of these apart before.  Anything to watch out for?  I think it is a Dana 61 but I have not been able to locate the tag yet.

[Gary Lewis]

Helpers can be a huge benefit.  Looks like you have a good one.

On the u-joints, did you rap the bottom of the U with a hammer after installing the joints?  That tends to spread the U and loosen of the joint.

As for the D61 axle, I've not had one out so I don't have any suggestions.

[Atlas75]

Gary, what do you mean by “rap the bottom” of the u-joint?  I did tap on the yoke rings numerious times thinking the vibration would help them settle in.  I’m just not sure where the bottom is.

[Gary Lewis]

Pardon the crude drawing of an and to a driveshaft and the u-joint, but rap where the red arrow is pointing.

[ArdWrknTrk]

And be sure not to overtighten those U-bolts.
If you do the caps will distort and the needles will be toast in short order.

(I've learned this lesson too many times now!  )

I forget what the torque figure is, but it isn't as much as you might think.

[Atlas75]

I sure hope I didn’t over tighten them!  I used a short wrench and tightened them with the trans in neutral.  So I could only tighten them as tight as I could hold the driveshaft from turning with my other hand.

[ArdWrknTrk]

12 for 5/16 and 20 for 3/8 if I recall.

If you had the wheels off the ground I don't imagine you got them too tight.

[Atlas75]

Does anyone know the size of the rear axel spindle nut on a 1980 f350?  I keep seeing 2 3/8 and 2 9/16 so I'm not sure which one I need.

Update:  I decided to just open it up and see since i need to get to the brakes anyway.  Looks like 2 9/16 according to my tape measure.  I ordered one on Amazon and as luck would have it, it will arrive tomorrow!

[Atlas75]

I thought I would switch gears a bit and work on the heater controls.  My truck has the simple system with only temp, heat/defrost, and fan control so here is no vacuum.  The cable out under the hood had been wired into a permanent position.  I undid the wire and noticed pretty quickly that the reason it was wired was because he cable was frozen but it did wiggle just a little bit.  I decided to spray penetrant into the cable and see if I could work it free.  To my surprise, after many sprays and working it back and forth, it was moving reasonably well.  Still needs more work but it is moving.

Next I went into the cab and got to the controls and noticed the temp slider moved way to easily.  After disassembly I realized someone had cut the cable! . Any ideas on how to reattach the cable or if there are replacements available?

[Gary Lewis]

That's a bummer!  You got one cable freed up only to find the other one had been cut.  

To replace it you might get lucky and find one via the part number, shown below from our page at Documentation/HVAC.  But more likely you'll have to go to a lawnmower shop and have them make you one.  They might be able to use the old outer housing, or may just make a new one complete.

[Atlas75]

I just found this but the part number is different.  The clip on the end looks correct though.  To bad it is out of stock.
https://www.dennis-carpenter.com/trucks/heater-amp-ac/heater-cables/e0tz-18552-a-air-control-cable

[Gsmblue]

Also, if you pull that cable out, i bet a bicycle shop can make one real easy.

[Atlas75]

Thanks for the lawnmower/bicycle shop ideas.  I think I'll give those a try before buying a whole new cable.

[Atlas75]

I finally located my rear differential tag today under 40 years of grease and oil.  I had to scrub on it for a bit to make it legible but I think this is what it says.

4.10.     E0TA.     ARA
603947-4.       L.      S

Sorry my phone keeps adding periods where I don't want them.  The only one in the above is between the 4 and the 1.  Can anyone interpret this tag for me?  Some of it I think is pretty straight forward but some of it I have no idea what it means.  Here is the original if it helps.

[ArdWrknTrk]

It is a 4.10:1 limited slip axle

EOTA    ARA  are the prefix and suffix completing the Ford engineering number.

603947-4  is the bill of materials, aka BOM