F-1 rear axle question

Vanspeed

Vanspeed

Well-known member
In my journey to give my old truck life again I have discovered another issue. There is a sound that I thought was coming from the trans. I jacked up the back and started it up. First gear is pretty quiet so I put it in 2nd. Noise got louder and even louder in 3rd. The sound to me is coming from the rear axle. The pinion feels pretty sloppy to me, there was hardly any lube in it either. I believe it is a Dana 41. I have no tag to id the gear set. It was originally a 4 spd. How cheap are these rears to rebuild? Should I be looking at another f-1 rear with a better gear ratio? Do these rears pop up for sale often? I do not want to swap out to a newer rear as I am keeping this truck as original as possible.
 
Stock 48-late 50 F-1 rear axle was 3.73. If you can find one in better shape, questionable these days, that would be quick and easy. 3.73 is really a decent ratio, 3.50 is about as low as I'd go, and it gets pricey to get below 3.73 (carrier break point).

If you want to go to a lower ratio, Randy's R&P sells the parts needed to put modern gears in your old case. But it won't be cheap. You have to replace the carrier, the R&P, and side gears, from what I've heard you're looking at an easy $500 in parts alone. And Dana's have to be set up carefully or they make noise, so mo' money there if you farm that out to a pro. http://www.ringpinion.com/Default.aspx

I know someone with two 3.73's, condition "average" I'd say, but nowhere near you. There are likely plenty of them out there from guys doing 9" swaps. It would be well worth your time to open yours up and see if it just needs bearings.
 
Think I will put a wanted ad up for one and maybe put one up on craigslist too. After filling it, she is leaking pretty good so no wonder it was empty. Does not look like it has been serviced in a long long time. I suspect the bearing is shot as the yoke has way to much movement up and down, in and out. I tried tightening the nut on the pinion but it is snug.
 
More than likely your pinion bearings are bad and the source of your noise. If you have that kind of up and down movement, fluid is probably pouring out quickly. It was run dry, then run some more and wiped out the bearings, Who knows what other damage has occurred. Take the drive shaft off the rear and remove the pinion flange off and see what the outer bearing looks like. Once the flange is off, you should be able to slide out that bearing. Be careful in case there is any shims. It been a long time since I messed with these rears, so there might be shims on one side or the other of the bearing. Napa can get the pinion seal if you repair what you have. Bearing also. Probably easier just to find a rear and swap it out.
 
If its a 41, there should be a '41' cast on the case, usually front and low , covered by gunk. In spite of one of the posts above, I believe you will have trouble finding enough 41 rebuild parts. If you have to have a 41, take up the offer of one of the guys offerring one. Personnaly, and I know you didnt ask for opinion, but my choice would be a 44. Looks pretty close to a 41, and parts are available.
Having said all that, take it apart and see how bad it is. Odds are against it, but you might get lucky with a pinion bearing and seal??? Even set up correctly, it will probably make a howl, and maybe you are willing to live with it??
 
The D44's used from 51 - late 50's in Ford trucks used a unique axle spline and side gear shape, such that modern D44 parts won't directly work. That's what Randy's has, is special side gears that allow the newer carriers to work in the old housing.

There are literally a thousand posts over on the FTE site about how to skin this cat. Most over there do not value originality, but a few have done the conversion using Randy's parts or homemade adaptor bushings. By far the cheapest route is to get an Explorer axle, but they have the wrong wheel bolt pattern. The correct 9" is getting hard to find and most are pretty worn out. No matter how you do it, it's a $500 - $1200 proposition.

The 41 or 44 is cast into the rear lower part of the housing on the trucks
 

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Thanks guys. I guess my first order is to check the pinion bearing. Seal is trashed so I imagine the bearing is too. Good thing I have not really driven it since I bought it. The last owners drove last way back when so maybe a bearing will do it but I think it's future is limited. The axle does have a D 41 stamped on on it passenger side near bottom.
 
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I have a 9" out of a 1960 6 cyl 3 spd F-100 if you decide to go that route. It has not been on the road since 1977 when the engine put a rod through the block. Likely it will need new seals and brakes put on it. I have not checked the ratio yet. Rod
 
Ross F-1 said:
The D44's used from 51 - late 50's in Ford trucks used a unique axle spline and side gear shape, such that modern D44 parts won't directly work. That's what Randy's has, is special side gears that allow the newer carriers to work in the old housing.

No matter how you do it, it's a $500 - $1200 proposition.

The 41 or 44 is cast into the rear lower part of the housing on the trucks
Click to expand...

I'm thinking more along the Jeep line. Has correct 5 on 5.5. But not just any Jeep. Some are more appropriate than others. 70's if it's narrow track. Some have flanged axles - desirable IMO. If wide track is needed, than 86 CJ would be the one. I wouldnt be looking newer, for various reasons - mostly wrong wheel pattern. I've got a 70's - 80 Scout 44 in one of my vehicles, but it's pretty wide. If you need wide, it's a good choice - comes with 3.54 and locker, and flanged axles. The higher end of above price range was spot on for me, after I rebuilt it. Some Jeep wagons and pickups also have suitable 44's - wouldnt hurt to look, some have 5 on 5.5.
 
Ok guys, a guy about a half hour away says he has one from his 51 f-1. He says it has 2.5 inch axle tubes, same as mine. He told me the truck drove fine but he put an explorer rear end in it. Will this rear work for me?
 
Well I don't plan on doing any high way driving with it. If the 3.92 will allow me to go 50-55 I would be happy.
 
I have (2) 50 rear ends laying here, but they are in Virginia. I installed a 9" from an 57 F100 in mine. It was a direct bolt in other than adding shims for the pinion angle and adding the 57 crossmember for the shocks. I don't know how many miles were on the 57 with a 223 6 cyl, but the ring and pinion were pitted and the axles grooved from the seals. I had it rebuilt with a used 3.25 ratio ring and pinion.
Tom
 
Ross, does this explorer rear have drums or discs? If it's discs, I guess with a bit of machine work and buggering about you could fit the drums off your original rear?
I'd like to know as the explorer did sell over here, so it's an easier get able part, should I decide to change ratios. I guess the width is ok. PCD would need redrilling.
Many thanks,
Martin.
 
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