Technical Question on identifying rear end/leak on Shoebox Ford

Hi All,

I have a shoebox Ford with a 350/350 combo. I don't know what rear end is in it but it does leak and while I'm going through the car carefully I'm trying to take care of everything I can while I have the chance.

Does anyone know if the rear end is indeed an 8" Ford or what it might be? Also it seems to be leaking at the pinion seal (I think that's what its called)... the orange seal in the photo. Would this be a difficult job? I can see there is a pinion nut but would that require taking the axle out etc.? I remember doing this seal on my 53' Chevy and it not being too hard and not having to take out the axles but don't know if a Ford would be much different. At least for now the leak is minor and does get on the floors but does not get anywhere near the rear wheels/brakes.

 

Break open that input shaft to replace the seal and you're going to have to reset the lash, replace the crush sleeve, and this will have to have the pumpkin out on the bench. Me? I'd slide a pan under it when I parked it until things got ridiculous.

 

looks like it's probably the original rear end. Not an 8", which was invented several years later.

 

Scrape the grease of it and find identifying numbers?

 

Ah ok... yea I'm not willing to do that right now... its not even really dripping on the floor much at all but I do see it wet on the floors however it stays well away from wheels and brakes. I will add this to the list for one of those when I'm really bored which will probably never happen in the next 10 years

 

Oh ok yea may very well be original.. the previous owner didn't know.

 

Thanks that's something I can try!

 

Definitely not and 8" or 9" Ford.

 

The funky U joint and the small round center section are solid clues that it's the original 49-56 style Ford car rear end.

 

Thanks! Replacing a seal on one of those original Ford rear ends requires way more work than say a 55-57 rear end? I remember replacing the seal on one of those and not having to take the pumpkin out and mess with crush sleeves but maybe I didn't do it right.

 

I know you're not supposed to, but I'm sure I've changed well over 100 pinion seals without replacing the crush sleeve or anything other than the seal. A very long list of customers over a long time period (40 years) and no bad results. You do have to be careful and make sure the bearings feel good after you tighten the yoke back up, not any end play and not so tight it is too hard to turn. A pinion nut that will hold it's position, as in a good lock nut, so it doesn't back off in service makes all the difference. Years of experience can make this a pretty easy repair that will last a long time with out too much fuss doing it. Note: if the bearings are bad to begin with or the bearing preload not correct your results will be less than favorable.

I did the pinion seal in my own '50 Ford about 3 years ago as described above and things are still good 4500 miles later.

 

Awesome thanks for the advice and encouragement. I will attempt it then!

 

If it takes significant torque to get the pinion nut loose, then you'll probably be fine just replacing the seal.

 

Ah ok... one thing not going for me is I'd have to do this with the car on jackstands. I wouldn't be able to break that nut free with the wheels on the ground because of the airbag suspension setup. Any tips how to break that nut free?

 

you could make the proper tool for the job...which is a long flat bar that has holes drilled in the end, that match the holes in the yoke that the U joint bolts to, as well as a hole in the middle to allow the socket to fit onto the retaining nut. Bolt the tool to the yoke, use a long breaker bar to loosen the nut. This is also needed when you torque the nut back in place after changing the seal. Of course, most guys who do this for a living just use an impact wrench, and don't worry about it.

 

Thanks I can make a tool of some type for sure!

 

I wasted $20, and use this one: https://www.summitracing.com/parts/rat-18001

 

Awesome... I may just get that one!!

 

I am guilty and can a test. Impact off the nut, pry bar off the yoke. Screwdriver and hammer the lip of the seal in enough to pry it out. Tap on new seal, reinstall yoke. 3-5 ugga dugga's with the impact on the nut. Or do it the right way and save yourself the trouble of messing something up.

 

I have an air compressor but I don't think it's quite big enough for impact tools

 

If you really want to get into it, I guess a rachet and a really long pipe on the end might get it lol. Wheels on the ground, either the car or the nut is going to move.

 

True, except if the wheels are on the ground and I'm under it I'm likely to be a pancake as its on airbag suspension and I'm still working out the leaks

 

Matching marks on the nut and the pinion shaft, count the turns taking the nut off, replace seal, reinstall nut the same number of turns and just a smidgen tighter than it was. Done them this way for 40+ years and never a problem. This is if there's no play in the bearings before you start. If there is any up/down movement when you try to wiggle the pinion shaft the bearings are bad and it's overhaul time.

 

Thanks so much I will follow your suggestion when I do this hopefully over the weekend! Thanks

 

Keep in mind that there's a minimum torque that the pinion yoke retaining nut should be torqued to....if you leave it loose, it really isn't doing it's job of holding the yoke on.

 

Remove the drive shaft….Mark the nut on the pinion end to put it right back to that spot make sure you mark the yoke also….both in the exact same spot and then test the lash buy moving the pinion back and forth checking to see if the feel was the same as before you started.
The u-joint is called “mechanics” style.

 

Hi, does anyone know how I would drain the fluid prior to removing the seal? I can't tell if the small bolt with square head on the back is the drain plug? See photos. To refill would I take one of the bolts out with red arrow in photos below?

Also another thing I noticed is there doesn't seem to be a breather. I see a bolt that is solid on the passenger side and another bolt that seems like it has a hex indent (for allen key it seems) but also seems solid and I poked with a scredriver in the indent and it didn't seem like an opening. I imagine one of these is where I would fill fluid from? See photos below. I wonder if the reason it's leaking out is lack of breather. I suppose if I wipe the leaking fluid and it doesn't keep leaking while the car is on jackstands that might be a sign? Thus far I haven't seen anything leak onto the ground/carpet there is just some gear oil around the yoke/u-joint connection.

Thanks

Pic #1 - Is this the drain plug?

Pic #2 Is this another drain plug?

Pic #3 showing fluid on yoke/u-joints



Pic #4 Bolt on passenger side.. looks like a breather should go here instead or is this a fill port?



Pic #5 bolt on driver side. doesn't look like a breather to me....


Pic #6 another view of the bolt on the driver side.. doesn't look like a breather to me.

 

Probably one of those bolts on top used to be a breather bolt, but was replaced when someone did that suspension work and relocated the brake lines. You can buy a new vent bolt, for later rear ends, make sure it's the right thread.

#1 looks like a drain plug. #2 looks like a fill plug.

 

The lack of a vent is probably why it's puking a little past the seal...

 

Thanks that's what I'm thinking... its not leaking when on jackstands at least not on the ground. I'm going to clean it up well and monitor before I go messing with the pinion seal.