I recently acquired a '73 High Boy, 390 with a 4 speed manual... And I have a few questions about this vehicle... The truck runs and drives phenomenally... But there are a few problems that I have not encountered before... For instance, on both the front and the rear axles the input shafts leak. A friend of mine said it could possibly be a plugged breather but I have yet to find a breather anywhere on the axle housing. Also the front is a closed knuckle Dana 60. And it leaks oil around the knuckle. Also the rear springs are sagging just a bit and I was wondering weather I should get a set of factory spec springs or should I go with some 4" lift springs and get rid of the "axle twist" blocks.

A little history of what has and I have done to this truck are as follows...

Before I got the truck the previous owner (a good friend of mine) installed and after marked cam and heavy duty valve springs. He also installed dual 3" strait pipes with turn outs in front of the rear tires... Since I have had it I have installed a edelbrock performer 390 aluminum intake manifold and a 600 cfm edelbrock carb... The motor runs fine and has good compression and the original 4 speed manual is still strong...

Any help about the before mentioned problems would be appreciated...

-thx

 

sounds like the seals in the front end need replaced, not going to cost you much money at all for just seals. i think theyre way under 30$ for both. as far as leaking oil at the pinion, i have no clue, some type of seal probably went bad.

 

Yeah that is what I was thinking but I just wanted to be sure before I tore down my axles and found out that it wasnt the problem...

 

well, that would be my guess. it will also give you the opportunity to lube your hubs too.

 

Another thing I was thinking... considering that this truck has manual everything and closed knuckle front end... I was thinking about trying to find an open knuckle front end so I could have some semblance of a turning radius... Also if I found the right axle I could get disk breaks... The other thing I was considering was pulling the dana 70 out of my '71 camper special and putting it in the back of my truck considering that is a little tougher axle and has the heavy duty breaks on it...

 

It sounds sweet, lets see some pictures.

 

My digital camera is inop at the moment but as soon as i get it working the pictures will be forthcomming...

 

sounds like a good plan. make sure your gears match. you'll also need to get a master/booster/prop valve for the discs. i'd try and find a d60 from a 78-79. wait, that is what i did.

 

first off...WELCOME toFTE.the axle vents are on the driver side axle tube top of both front and rear axles.they both should have a rubber hose leading up to the frame ,the hoses are longer so there will be enough slack in them to allow for suspension travel. if there are not rubber hoses on the vents,then look on the top of the axle tubes for a bung. they are threaded in and they normally take a 1/2 wrench to remove them. the leaks may also be the pinion seals. they are easy to replace.just take the drive shafts out and remove the yolk. the front closed knuckle leaks are from the unitized knuckle seals.there are 12 bolts holding the metal retainer plates on. these plates are half circles. there will be a top side and bottom side half circle retainer plate.then under that there is a felt seal that goes all the way around the knuckle,it is split in one spot so it can be installed. under that is a rubber/steel scraper seal,it rests on the sphere of the knuckle. make sure you install the rubber/steel seal with the split at the top of the knuckle so it wont leak. there is a filler plug on each knuckle on the upper side of the back of them.you can see the filler plugs by looking in the back side of the wheel wells behind the front tires.the knuckles take 90weight gear lube.these kits can be ordered from Jeff's bronco graveyard or other ford sites on this forum. i would be willing to bet your front diff is actually a dana 44,or a dana 44 HD,not a dana 60. it would be really really unlikely for it to have a dana 60 with closed knuckles an drum brakes.these old trucks came with 360 FE block engines,but your truck may have a 390 swapped in it.they never came that way,but many are changed.many of these trucks engines magically changed from 360 to 390 right as they were put up for sale.360 has a 3.50 inch stroke while the 390 is 3.75 inch stroke. (well that was a lot of explaining! lol.) hope this helps you .good luck -billy

 

Yeah part of this whole project is also gonna be a power brake conversion and power steering conversion... cause honestly as fun as the truck is to drive turning it around is a pain in the neck... my friends say that this truck has a turning arc not a radius... so my hope is that the open knuckle dana 60 will help with that a little... i mean there is not much I can do to compensate for the 36" tires i have on it... also when all is said and done I am also going to put disk brakes on the rear as well...

 

That's part of the appeal of theses old beasts, the three point turn lol.

 

are you sure it isnt a closed knuckle HD Dana44...... ive personally never heard of closed d60s

 

I am sure that it is a closed knuckle dana 60 I have ran the numbers on the axle houseing and on the id tag... as for the vent tubes thanks alot after more searching with your directions I was able to find them and verify that they are in fact not plugged... with means it is off to the parts house to get new seals... Here is another question on that... since I will be replaceing the seals and doing a full inspection of the axle and thus removing all the oil... should I go with the original oil or is there something that anyone whould recomend as an alternative...

Thanks much

 

Happen to have that axle ID tag number handy?

Where did you run the codes to find out what axle it is?

As original...the 1973/75 F100/250's came with Dana 44's.

There were two offered. Dana: 44-6CF or 44-6CF H/D.

 

look on the corner of the front cover on a rib it will be stamped 44 60s only came in a f350 witch are very rare and also has anyone heard of a 428 scj in a highboy check youtube 74 highboy he says its a 428 scj