Can anyone advise what thickness of gasket I should use to assemble the rearend in my 48 F-68 ( 1 Ton ). It has a Rockwell rear end and I cannot see anywhere what thickness of gasket that it might be. Any suggestions on clearance or backlash adjustments would be appreciated too. Did it take 80/90 oil ?

 

Dwayne,

The stock rear axle on the Ford F-3 was a Timken 51524. I don't know about the F-68, did it come stock with the Timken axle like the Ford, or with the Rockwell axle you mentioned? What model Rockwell axle is it? Can you find a tag so we can ID the rear end and help out?

There were several posts in the past few months discussing rear axle cover sealing methods. Use the search function (near the top of the screen) to see if you can find the threads. I usually use the advanced search option so I can limit my search to just the 1948-1960 forum.

If it is a stamped sheet metal cover, a couple of us (including me) have found that the gasket actually makes it harder to get a good seal. I've used Permatex Ultra-Blue (or you favorite brand oil-resistant silicone sealer) with good success. I didn't even put a new gasket in - just the Permatex, and there have been no leaks for about 3 years. I have to warn you that my truck is on the "ten-year plan" , so it has not been on the road since I rebuilt my axle a few years ago. Still, the oil is in the axle and I've run the engine, transmission, and axle with the rolling chassis on jack stands for 30 minutes every couple of weeks to keep things lubricated.

Good luck and keep us posted on your progress.

 

You probally mean the Timken axle that is split down the middle? (Earl Rockwell bought out Timken's Axle division in the late 50's) You can't buy a new gasket and they are a pain to put back together. You could try silicone but you might need someone else to help you slide the halves together. 80/90 oil should be fine. I've given up on those axles (I have two M-3 trucks. They are the same as the F-68/F-3 trucks) as brake parts are almost non-existant. They seem to have a problem blowing the rear pinion bearing. When it goes the rear axle is basically shot as it can make the pinion side useless by breaking the casting and it usually chews up the ring and pinion gears. Since you have it apart check the rear pinion bearing for slop and if it's worn you can't get a new bearing. My first trucks axle looked like it had exploded and the oil was silver from metal shavings. The second truck had the pinion side replaced from a newer truck. There are a couple examples of these axles on the net that have had the same problems.

 

It is a 51524 as you mentioned. I just assumed it was a Rockwell because it looks identical to a schematic I downloaded awhile ago. The F68 is an F3 I believe, It's a Canadian term I believe. I have replaced all the bearings and I am now in the process of closing it up. I'll keep you posted if I have any other problems.
Thanks for the info.

 

My truck originally came from Saskachewan a few years ago apparently. Thanks for your advise and may I ask what you used in place of the axle instead of the Rockwell?

 

In my 1st '51 Mercury M-3 I'm running a Dana 44 out of a '51 F-1. I've converted that one to a F-1 suspension. I've put a '74 F-350 cab and chassis Dana 70 in my other '51 Mercury M-3. The width is perfect and it bolts up. It requires driveshaft modification and new spring bolt plates. If you've redone the Rockwell axle it will probally be fine. The trucks I have been overloaded many times (hauling manure and water). When I still had the Rockwell axle I had the truck up to 175 km in a field. Since I put a more powerful engine than the stock flathead in the truck I just wanted a stronger axle that shouldn't leave me on the side of the road. Good luck with your project.

 

If you're looking for a gasket, I found some. Part number 61 4035

Green Sales, Cinci, Oh. 1-800-543-4959 14 in stock.

Barry

50 F-1

 

Would you know how to adjust this axle if there is excess backlash? It is the type that I will have to put together and pull apart I see to get it right but where would I adjust the ring gear? I have a little bit of freeplay between directions (maybe 3/8-1/2" in directional movement of the hub when I turn it back and forth) I am not sure how to measure it.

 

Do you mean you can turn the axle hub 3/8 to 1/2" before the pinion moves? You should try turning the pinion yoke instead as that slop may be because it's an open differential. My shop manual doesn't list any backlash adjustments for this axle. It lists pinion preload.

 

I'll check that out tomorrow, and yes that was at the hub. Do you mean the pinion drive shaft or the pinion assembly in the differential assembly?

 

Yes the pinion drive shaft. Every rear axle I've had will rotate slightly before it moves as that is the nature of gears.

 

Do you know of a replacement hanger bearing ( center support bearing), off of this 48, F-68. I have it all apart and it has an oiler on it. I think there might be something better out there that would provide a better seal. Would there be a bearing that might just press back into the casing?
Thanks in advance. It has an 1.378" inner race. I can get the bearing itself but the seals and etc. would be an advantage to upgrade as well.

 

Dwayne,

If you know the OD, ID, and thickness of the bearing, you local NAPA or similar auto parts store can try to find one to match. Whether the folks at your particular store are willing to do it is another matter.

I needed an odd size for a home-built project about five years ago and the local guy was great. He took out his Timken book and looked up a bearing that worked just right. He also had a seal book (can't remember the brand) and had looked up a seal for it - but I didn't need a seal for my project. You might give it a try.

 

Thanks for the advise. I have gone to the local bearing supply store and was able find the bearing that is housed in the assembly, but that was all. I would like replace the old seal arrngement if possible because they are just the ol' felt type packed in a groove and oiled periodically. Maybe this is just wishful thinking. I have thought of modifying a newer style ( the mounting arrangment) but would rather try to keep the ol' housing etc. as much as possible.
Just tryin to make a good thing...better
Dwayne
p.s. I will keep you posted of my outcome.

 

Hey dwaynewoodman

I am thinking I must have the same rear you have cause it's a split pumpkin. Mine is in my 55 F250 (Dually, with 6 lugs), identified as an option in my original Ford Truck Dealers Manual.

Can you pass along where you have found bearings, brake parts...

I wanna Keep my original Dually if Poss. I don't want to start changin the rear end then finding a new front axle to match the new rear lug pattern. That starts another snowball becoming an avalanch of changes. For God's sake, it already feels like a runaway train!

Thx. David