The Daughter’s ‘84

[Atlas75]

I’d like to introduce the newest member of our bullnose family!  It is a 1984 F250, 6.9L diesel, 4x4, T19 truck.  My daughter has been looking for a truck for a while and this one fit the bill.  It also has A/C!  Anyway, here is a photo.



We have a few things to work on before she can drive it to school but it runs, drives, and stops good so the basics are there.  I think her truck is in better shape than mine!  I like this photo because you can see my 1980 in the background.

[ArdWrknTrk]

Well done!

I envy the members who can find a serviceable Bullnose truck.
The winter salt and mag chloride here in the Northeast just eats them up...

She looks quite happy and proud of herself.  (As she should be 😉)

[gaveasky]

I've got an 83 in the exact same configuration! That thing is in great shape and I wish mine had AC. I look forward to hearing more about it.
  Do the glow plugs work?  Took me two days to hammer my PO's old ones out and put a push-button setup in my F250.

[Atlas75]

The glow plugs do seem to work.  The PO replaced them shortly before we purchased the truck.  This truck also has a push button for the glow plugs.  I assume the controller is the issue as they frequently went bad.  I plan to rebuild the factory system with a solid state controller and eliminate the push button.

[grumpin]

I had a 1988 F250 with the 7.3.

I finally went through the glow plug system, found burned connectors, bad glow plug connecters etc.

Got it working good.

One thing that really helped was I used a heavy duty appliance timer for the block heater, when it was cold I would have it come on two hours before I left for work.

If it was really cold, three hours. And use the OE block heater, they are good.

Also use good glow plugs, I think Beru was the brand then that was best.

The other glow plugs wouldn't last long and they would bulge on the end when they failed. Which made for nerve wracking removal, not wanting them to break off in the preignition chamber then going into the cylinder.

Here's an example of the timer, https://www.homedepot.com/p/TORK-15-Amp-24-Hour-Indoor-Plug-In-Heavy-Duty-Appliance-Timer-with-2-Outlet-Receptacles-White-RTN312/306607224

[Atlas75]

Where is everyone getting their vacuum hose and fittings for the heater controls?  I have been researching the size and material but am coming up with varying answers.  I need to do further testing but I am pretty certain there is a line or two that have leaks or have collapsed.

[Atlas75]

Will a Sterling 10.25 from a 1987 F250 bolt into an ‘84?  A local yard has one with 3.55’s and limited slip.  I think it would be better for highway speeds vs. the 4.10’s that are in it now.  Thoughts?

[grumpin]

I think it should bolt in, but not sure. Someone will know.

I had 3.55's in my old 86 F250 and I really liked them. Always had 4.10's, that truck had no problem pulling with 3.55's and the 460.

[Gary Lewis]

I also think it will.  But what are you going to do about the front?  You can't use 4wd with two different ratios.

And on the vacuum line question, which I'd missed, I buy bulk vacuum line from the local parts store.  But I don't remember what size.  I cut into the line I'm replacing and determine the size by slipping a drill bit in.

[Atlas75]

I need a little help determining what the rear axel is in the ‘84 F250.  The axel code on the door sticker is 72.  That code does not have a listing for 1984 in the rear axel documentation on this site.

The Dana BOM number from the axel tag says 605205-7.  That code comes back to a 1983 to 1985 1/2 Dana 70 from a chassis cab F350.  The truck is not a chassis cab.  It is a pickup.

So you can see the issue?  The two pieces of info seem to conflict.

[ArdWrknTrk]

Clear pic of the door tag???
Are you sure it's not code G2? Which would be a 4.10 LS Dana 70U (6,300#) in a pickup for '84-'85?
Code 72 seems correct for that same axle in an '85 Model Year according to Gary's list...

What is the wheel mounting width (track width) of the axle?
Chassis cab would have 34" wide spring perches and 2 1/2" wide pads for the springs.
Have the perches been re-welded?

I used to see more 70's in vans than in pickups. (but, again the frame widths are different)

D70 should have 3 1/2" tubes and 70 cast in the lower right quadrant web as shown in this illustration from the Spicer service & maintenance booklet.

[Gary Lewis]

The 605205-7 does decode to E4TA 4001-BEB or BEC with a 4.10 ratio in an 84 F250/350.

[ArdWrknTrk]

Is one limited slip and the other is not?

Because it seems G2 is LS and code 72 is open.

[Gary Lewis]

Both show as open/unlocked:

[Gary Lewis]

And I should have posted this to complete the loop:

[Atlas75]

Here is the door tag.  Even though it seems like we solved the issue.  Dana 70 it is!

[Gary Lewis]

Looks like "72" to me.  

So we have another instance of one part of the MPC being wrong.  As shown below it says that an 84 didn't get that axle.  But here's a truck made in January of 84 that got one.  

Glad you had the BOM so we could look it up another way.  

[Atlas75]

I haven't posted in a while but my daughter has been enjoying her truck.  So far we have upgraded the stereo and done a few things to the glow plug system.  We still have more to do with the glow plug system as we attempt an upgrade to the 7.3 controller.  More on that at another time.

My question for today involves the clutch.  My daughter drove to work yesterday and everything was fine.  On the way home however, the clutch pedal would only return half way.  If she didn't use it for a bit, it would slowly return to the resting position.  I haven't had a chance to crawl under the truck yet but this sounds like it could be the slave cylinder.  Anything else I should be looking for?

[ArdWrknTrk]

I don't think the slave cylinder is going to magically suck fluid back in, but at least it's external and you can pull back the rubber boot and look for fluid.
Has the level in the master gone down? (don't forget the rubber boot sometimes sticks and makes it appear dry)

I'd be looking at the 4 fingered bushing that connects the pedal arm to the master pushrod eye.
When that bush wears through you get poor adjustment and eventually the eye wears a groove in the pin of the arm.
When that happens replacing the bush results in a crunch and immediate failure.

In an emergency I temporarily fixed this by JB Welding a 9mm casing over the pin and using a washer & circlip in the extractor groove.

Also look at the plastic bushings where the pedal crossover shaft pass through the support casting.
I've never encountered it myself, but pictures on the forums leave no doubt that it happens.

If the slave proves good, these are a good place to start.
Basically you want to remove as much linkage slop as possible without preloading the master to the point where it closes off the reservoir.

This is just my experience, and others may have more to add.  

[Atlas75]

I checked the slave cylinder and it appears to be dry.  I'm not sure why, but I never checked the clutch master cylinder fluid level when we bought the truck.  It was quite low so I topped it off.  I also noticed that the seal/boot under the cap was really distorted.  I don't think it was making a seal between the master and the cap.  I wonder if the fluid evaporated slowly over time?  I tried the clutch both with the engine running and with it off.  It seems to be functioning as it should now that the fluid level is good.  I'll try to take it for a drive tomorrow and see what it does.