I'm just lapping in my rear axles and hubs with valve lapping paste and it crossed my mind that I don't know the best way to assemble them. Do I assemble them dry or do I want a smear of grease or anti-sieze on them? I can see pros and cons for both but I am guessing there's a right and wrong way. thanks Pete
OK, maybe nobody knows. I'll value add to this thread. I was hesitant at first to lap my hubs and axles, thinking it might be a fair bit of work. But I decided to do it because I have read many peoples opinions that it greatly increases the likelihood of survival of these axles when you put decent HP through them. I shouldn't have hesitated and neither should you. $10 worth of valve grinding paste and about 1/2 hr per side. Check out the before and after pics. You can even feel the improved fit after the grinding. before - lots of pitting after - nice and smooth after about 30 mins Now, can anyone answer my original question? Pete
That was my original thought too. I'm thinking if I assemble them dry they might eventually become one, never to be separated.
I've been using anti-sieze on my 32 banjo and I have been able to get the hubs off no problem. Also, the thing never came apart on me even though I had some 'challenged' axles. I am now rebuilding the read with NOS axles. I have been thinking of replacing the hubs/drums with new parts. My question is, does the lapping really only make sense with all new (or very good used) parts? I am kind of wondering how much wear and tear my old hubs have, and after all the damn work to rebuild the rear I'll be damned if I ever will want to pull it apart again.
I'd say lubed could not hurt, and might actually increase the drive into the taper fit. I suspect that with a good fit nether lube nor rust have much space...I have found clean tapers on rear ends so rusty I would not want to use even the axle tubes. Fit is probably pretty much air tight when good. Proper fit and tightness are good, but make the next disassembly hell. On the lapping...I found a Clover page in the MSC Industrial Supply catalog...there were 10 or 12 grades, not just the two that come in valve grind cans! grades ranged from about angel dandruff to gravel. Some of the finer ones might be well suited to this.
I don't know for sure but it must be better than all that pitting. Here's anothe shot of the finish. When you slide the hub on you can actually feel it take up and feel tight. It didn't feel that way before.
I hoped you might chime in, Bruce. Now I'm thinking 10 or 12 grades of compound IS starting to sound like a lot of work! My thoughts on the anti seize were similar to yours that it might actually help the tapers pull up that bees dick further. I'm going out to the shed. I want to put this chassis on it's wheels today. (Got some new Firestones!) Thanks, Pete
It needs to be metal to metal tight and a film of grease will keep it "floating" allowing the back and forth rotation of the hub to hammer on the Woodruff key until it shears it off. Assemble it dry. Clean any moisture out of the parts with something like WD 40 if you're worried about moisture/rust but wipe that off too.
I think lapping is probably unnecessary for new or real good ones...you can just push them together by hand and they'll fight you when you try to pullemoff. Real tight tolerances if not damaged in use. Aside from rust, most common damage is from fretting if they were not tightened down hard or often catastrophic wear from using axle shims.
See, now I'm unsure. The good doctor says one thing and Bruce says the other. Like I said in the beginning, I can see both arguments. What did Ford do?
I don't want to come off as an expert here, especially with guys like Bruce Lancaster here on this board. In my experience in the repair and maintenance in the mining industry we never apply any lubricant on tapers. Any assemblies that have a taper are assembled dry. Most tapers I deal with are impellers in pumps. The reason for that is the taper actually acts as the locking mechanism as well as the key. It is essential that both surfaces be extremely smooth and have a perfect fit. Now maybe the old banjo tapered axles are totally different but I would think the same principals apply.
The tapers certainly do act as the locking mechanism. That's why I went to the trouble of lapping them together. My uncertainty comes from my lack of engineering background and whether or not the lube would be forced out during assembly as (I think) Bruce was suggesting. Pete
The taper itself is the lock...I suspect that you could throw away the key and never miss it on a properly tightened one. Ford used no lube, I've never used it, but I suspect it might help the advance of the axle into the hub that accomplishes the lockup. I really don't think that once the parts arrived under the push of 150 foot pounds on the nut that any significant lube would remain in the fit...as I said, I don't think there's even any air in there to allow rust. We are talking a fit in which exactly matched tapers advance until the hub is acting like a rubber band pulled onto something large. Try one with lube and then remove it; If the removal process does not reach a point where you fear puller or car parts are going to shatter, it didn't tighten right! And the lapping sure as hell improved that pitted axle!
Early Ford axles and hubs should always be assembled dry, dry, dry. Tapered hubs and axles should never have any lubricant of any kind on them at assembly. You never get a good tight fit unless the pieces are dry. Most rust on these parts when assembled occurs when sitting in a farmer's field for 40 years and having been improperly assembled before abandonment. The "fight" to break the hub free is your assurance that the fit is correct unless the assembly is a farmer's field piece.
in the engineering world of which i have only limited experience, tapers are assembled dry. Im assemebling mine dry. the finish on your tapers looks pretty coarse pete, may just be the photos.. Id try a finer paste and get it almost to shiny before assembly, imagine trying to get a morse taper out if it wasnt polished! maybe try that solvol metal polish in a toothpaste tube? also, DONT do the nuts up hard until seconds before the first test drive...murphys law states theyll have to come off again before then!!
DRY!! Even with the key and the keyway, it still depends a lot on the friction between the parts to keep things in position. If you use any anti-seize, or oil, or anything that can reduce the friction or grip between the parts, the hub can squirm around every so slightly until it loosens more and more with the stress and strain of normal use. If you use anything that can act as a lube, you can also sometimes find the hub travelling too far up the taper and either cracking, moving the brake drum too far into the shoes or backing plates, or even creating it's own extra clearances by squirming around even if you tighten the snot out of it. The reason that the recommended tightening-torque is so high is to prevent things from shifting or wiggling under heavy shock-loads. The last thing you want is to encourage slipping and sliding. Which also reminds me of another VERY BAD practice- At different points in time there has been a common practice that seems to come and go. I have seen quite a few people hone the inside of the vibration dampener hub for an easier (looser) press fit when they get tired of using a puller over and over to do cam changes. Never do that! The factory (any brand) goes through the extra time and expense to make the damper hub a tight precision press-on fit for a good reason. The harmonic damper (dampener) relies on that really tight press-fit to transmit the vibrations from the crankshaft to the damper. If you reduce that strong contact pressure that joins the two, you greatly reduce crankshafts ability to send the "harmonic singing" vibrations to the damper where they can be made harmless. Even if you don't end up with a broken crank, you could still greatly shorten the bearing life, cam gear life, or other... If your harmonic balancer does not fit really tight on the crankshaft, protect your engine by finding another dampener to use instead. There, two bits of advice for the price of one.
A good case is being made for assembling these dry, and I am paying attention. 2 questions: 1.) You are saying 'dry' as in do not use grease. What about anti-seize? If you apply sparingly and wipe it off well, you probably have a few molecules of AS on there. Is this a problem? 2.) Whenever I tighten the axle nuts I always am afraid of twisting these fragile ends right off, and then starting from scratch breaking it down and putting it back together again. Is this concern unjustified? Is the procedure of torquing, driving left and right circles, retorquing, and repeating the right way to go?
Anti-seize is a LUBE. If you said use LOCKTITE, that would make a whole lot more sense than using something slippery.
Could be a good point Ben. The finish is a very smooth satiny feel to the touch but I see your point about disassembly. That satiny finish is made up of minute score marks that may well be a problem. I think I'll get some polish and go again before assembly. Thanks for all the discussion here guys. Much appreciated. Pete
Another dry vote. And the Nut torque is 225 Ft/lbs. I think I read that at some internet site(the same place that explains the lapping). http://www.btc-bci.com/~billben/reartorq.htm But the important thing you done is the lapping. The taper holds, the key is not for transfering power. I had bugered up axles and hubs in my banjo in the T. Did the laping job last winter. I left the rough finish, as lapped. They hold well. So of course, I needed to remove the hubs twice since then. The puller would not get them off, needed to also heat the hub with the puller on as tight as it would go. Not red hot, just heat to swell it up and release the taper. BTW, put a drop of oil on your #2 Morse taper in the lathe tailstock and it will never bite, just spin.
Tapered shafts are always assembled dry. Would you put lube on a tierod end? Clean and polish yes. The better and cleaner the fit the less chance of loosening. The concern with twisting off the end of the shaft is not a real one. I think you'll find that that3/4" end does not toghten to 165 in lbs like a bolt but rather will be torqued to maybe 65 ft lbs. I'll look it up in the morning. The 5" tapered shaft the holds the sprocket on a d-9 Cat only torques to 275.
Talked to Elpolacko a couple weeks back, he lapped and ran em dry on a 400+hp sbc powered car. No worries. Steve tends to research and experiment til he finds a good answer.....ie; he knows his shit.
Always assemble tapered axles dry. If an axle shears or threads strip during torque it was junk and should be replaced same goes with the nut. A minimum of 200ftlbs is suggested.
Ah yes. Shims as a last resort or with low horsepower/moderate driving. And what brucelancaster says in another post here too. The key is probably redundant, but keeps the axle from spinning when undertorqued. No lube. Torque tight to the point that when you go to pull it next time, be ready for the fight, good/correct/adequate puller then put a lot of tension on it and go to supper. Sometime in the night hope it will pop loose. It usually does. Side note, I had one so tight(on my Nash, I wanted to cleanup/repaint and put the boiler plates behind the spokes) it took me the last four months to get it loose. I loosened the nut, drove it hoping it would come loose. Then when I got antsy I would put the puller on, moderate heat(not enough to smoke the wood spokes) hammer and wait, no luck. Tthen oh hell I'll try again another day. I did that for four months, then one day as I leaned down to loosen the puller, BLING! Just like that it came loose. Of course it had been on there for over 40 years, I know that.
Well I did one side with cutting compound and got a semi polished finish. I pressed the hub on by hand and couldn't pull it off without tapping it with a hammer, so I reckon that's about as good as these 60+ yr old parts are going to get. There are still some pits visible particularly in the hubs but that's old cars I suppose. Pete
The 200 / 225 ft/lbs scares me a bit! The threads on my axles have definitely seen better days. I see the point that if they strip or shear they were junk anyway...I just don't want that. Hey, Tman and Plym, don't give me the credit. I just asked about something I needed to know. All the guys that have provided the info have made this thread. Pete
whilst just echo'ing' all the previous, dry....you are relying on friction, so, you want a good fit (hence the lapping = good), but assembly dry, no anti-sieze, no oil, no spit, just clean and dry, with a good neat fit required. Once those suckers are on, you don't want to be regularly removing them. Cheers, Drewfus P.S. post some pics of that chassis on its wheels....since the arvo's almost gone
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