Much has been written about the hazards of running with old babbitt thrust washers in the diff. The question is often posed, how can you tell if you have 'em without tearing down the unit ? -
The consensus seems to be that tearing down for a proper rebuild is always the best solution, and should always be done if the state of the diff is unknown.
Given that millions of Model Ts ran millions of miles on babbitt thrust washers, it begs the question, why the urgency now ? Problem is, unlike cast iron, aluminum, bronze, or sheet metal, lead alloy parts appear subject to decay with extreme age.
One way to check for babbitt in the diff is to jack up the rear end, and give the wheels a good shake in and out. Any amount of "play" indicates thrust is excessive, and babbitt washers may be deteriorating. With a suction device, pull the gear lube from the "pumpkin". The "grey death" will indicate deteriorating babbitt washers by showing as metallic flecks in the gear oil. Sometimes there will even be a few larger fragments in the oil.
Rich,This might sound dumb but could you take a sample of the rear end oil and have it tested?? I think most equipment dealers/Cat do oil sampling.Bud.
Get a $10 boroscope from Amazon that attaches to your cell phone and peek inside your differential.
It also has numerous other uses that should not be discussed here
Like they say, you can't prove a negative. Easy enough to say yeah, its got Babbitt when you see Babbitt in the oil. However, the lack of it doesn't prove it has bronze. I wish there were a way to know for sure. Someone once suggested putting a tag on one of the housing bolts saying it had bronze after doing a rebuild. Not a bad idea, but I don't know that you could get everybody on board to do it.
KEN, you can do a fairly good test your self in this way,kleenx works good here,put 3 or 4 layers of them on some news paper in a warm place put a spoon full of the oil to be tested on the tissue give it some time to soak through, lift the first sheet and inspect, if there is metal collected on the sheet that will tell you what you will need to do.years ago gray hound never changed the oil, they had a filtration system they used to test the oil,oil never breaks down,it becomes contaminated,this contamination is what causes ware.filter this out problem solved.
If you live on flat land with no traffic and don't do much driving, you might get away with babbitt. But when you need the brakes such as going down hill remember that without the differential you are in freewheeling, not even the compression of the engine to slow you down. It is conceivable that you could go many miles increasing speed without being able to stop and run into anything which is in front of you or even go off a cliff if the differential goes out. Although replacing with bronze isn't the only way to keep things from going out, it as a very common problem which can be prevented. It isn't hard to take apart the differential and replace not only the babbitt but any thing else which is worn or broken. I would also encourage anyone who drives in traffic or on hills to have auxiliary brakes on the rear wheels too.
Having an orginal babbit thrust washer fail at 40 mph sure was an e ticket ride getting ole girl stopped. Did alot damage took out ring pinion
Plus few other items
I say if the car been restored since the 70s great chance these been swapped out
I pulled down a Ruckstell that had been sitting and the axle shaft no longer turned. When I pulled it down, the babbitt fell apart. There was no sign of loose babbitt in the the rear end. Of course if it had been installed and driven, you can guess what would have happened.
In my previous T the rear was the only thing I didnít rebuild because people told me ďif it ainít broken ....Ē The left rear wheel always leaked oil onto the brakes and wheel which should have been a sign to me. Well, I drove it for 37 years until one day I heard an amazing metallic crunch which sounded like it came from the transmission. Actually it reminded me of the old cartoons where you see engine parts fall out from under the car.
Luckily it happened right at the intersection of my property. I nursed it another hindered feet to the drive way. I opened the transmission cover and didnít see anything odd. Then jacked up the rear, put it in direct drive and turned the crank and the rear wheels didnít turn. I separated the rear halves and the thrust bearing bits fell out into the pan ... and the ring and pinion teeth were as sharp as razor blades.
I rebuilt the rear with new thrust bearings and a ring and pinion set. Interestingly I had always thought my transmission was noisy ... after rebuilding the rear axle ... the drive train was much quieter.
Nevada Bob and our two Marks' (that would make a great name for a country/western group !) experiences are testimony to the danger of old Babbitt washers disintegrating with age.
A later restoration may indicate bronze replacements, but my T was turned out around 2002, and has Babbitt. I like Fred's suggestion for a way to peek inside. Can anyone elaborate on the boroscope idea ?
I rebuilt my 23 Touring rear end in Oct 2017 after much discussion about Babbitt thrust washers. One suggestion was to drain the oil and check the oil or use a device to look inside and see if they're bronze. When I took the rear end apart, I found Babbitt that looked really good, and golden color, like someone painted them. I'm glad, I took the advice of this forum and took the rear end out and apart. It was a fun project, the books sold on this site, especially the one Model t front and rear axles, has good step by step instructions. At first, I was going to farm out the rebuilding, but my local expert was back logged, so I decided to make it a father son project. We did it and it was a fun and pretty straight forward project. So much so, that I have rounded up enough parts to build a complete spare rear end, including drive shaft and radius rods. That will be another fun father and son project, later this year.
A comment on the bore scope idea:
Do not suggest to your wife that we get a bore scope for her smart phone. She told me to stick it...
Well you can guess the rest.
Happy New Year to Everyone,
I got a $10 one from Amazon it was by SHEKAR direct and is now listed for $15.
It attaches to my cell phone, has adjustable LED lights, 16 ft cable, and is 7 mm in diameter.
I downloaded a free app to make the connection work.
It has a usb adaptor so it can be used with a computer, but I havenít tried that yet.
It came with a cheep mirror so it could look to the side and a hook that allows you the grab small things. Other mirror attachments are available that may be better than the cheep one they sent.
As for the thrust washer - I was pretty sure my T had Babbitt so I took my rear apart and found that one washer was 2/3 gone.
I was close to no brakes.
No matter what people say - Donít take a chance!
You could become a statistic even in the neighborhood
Don't assume that a "restored" car is mechanically sound. That term is applied with reckless abandon. When I acquired my 1923 touring it had been cosmetically restored pretty well. But the mechanical stuff hadn't been touched. One of the many things I've had to deal with was rear axle failure.
Thrust washer from my "restored" touring.
I think I have asked before about what causes the Babbitt to fail in this application but work so well in others. I am thinking it is something in the gear oil that is not in motor oil that is causing the breakdown of the metal.
Reading the comments got me thinking about the Ruckstell application. Considering that in a Ruckstell all the gear thrust is taken by the angular contact thrust rated ball bearing. So the thrust washer is just taking care of any axle thrust loads from RH turns and similar. Certainly I am not advocating using the ancient babbit thrust washer in a Ruckstell, but it is possibly not the area of panic as in a conventional T rear axle. What scares me more is people buying the cheap non thrust rated ball bearing for a Ruckstell rebuilding
I've also wondered why engine bearing Babbitt seems to remain stable while diff washers self-destruct. Only plausible answer is that the alloys are different. How many of you have encountered aged "pot metal" or "pewter" items that simply crumble from internal decay ? I sure have.
Les, the problem in a Ruckstell is less about load and wear than it is the possibility of a Babbitt part falling apart and binding the works. I think that's what happened in some form to the washer fragments Steve showed us.
It's all about the instability of old Babbitt washers- obviously millions of 'em worked fine for a fairly long period.
I just got done going back inside a rear end that had bronze installed maybe 6 or 8 years ago. The bronze washers were not still shiny bronze color. The edges were very dark, almost black. Im not sure they would be identifiable with a bore scope. Not that i wouldn't try, but I wouldn't hold out a lot of hope. I used one to try to see inside my differential to see what was wrong. I was able to see one chunk of metal in there with it, which was good enough to know it had to come apart. Turns out the carrier casting had broken into about 20 pieces. However, it wasn't easy to see anything in there with it. Maybe a better quality one would do a better job.
Likely that Babbitt in the thrust washer was unlike pour Babbitt in bearings, as those thrust washers were fabricated maybe using 'pressed' material method, note the copy line, lathe turned and power pressed.
For the brass replacements, its a tougher material in shock. Have dropped a brass one from hip high, it bounces and rings like a bell on the cement floor.
Then dropped an old Babbitt one, and it just shattered into small pieces!
Which do you want in your rear axle
Whoa !!! There's another facet to this adventure that needs to be noted. Not all gear oils are compatible with bronze parts. Indication of corrosion probably means that's the case in your diff Hal ? Of course a busted carrier is another problem, but I wonder if oils reactive with bronze might eventually cause the kind of problem we're seeing with Babbitt ??
It's also possible the reason diff washers come to pieces, and engine bearings don't is because of reaction to some kinds of gear lube ?
I wouldn't call it corrosion. Tarnished is more like it. I dont think there is anything wrong with them. The point was that they don't keep looking like brand new after a few years and are not necessarily readily distinguishable with a cheap bore scope like the one I have.
Mark G raised an interesting point. With a Ruckstel, a babbit washer disintegrating may not be a safety problem at all. The large ball bearing takes the thrust as the pinion gear tries to drive the crown wheel to the left, so the gears cannot get out of mesh, and drive/braking is not lost. If the right hand babbit thrust was to go out, the gears would become deeper in mesh on turning right,not a desirable situation, but not necessarily unsafe.
Or have I got this wrong?
Allan from down under.
Interesting topic, and I sure that there is good concern on having diff failure but in saying that I,ve never had one let go out of 5 T's that I own, never seen any fail on tours. Pulled many diffs down looking for the best of parts with babbitt all OK.
I do use the brass replacements and a tag on rebuilds.
I've never broken a crankshaft either! so I don't race out and fit Scats to my engines just in case!!
I learned about the thrust washer problem when a right rear wheel locked up while I was driving in town. I brought the car home on a trailer and found this.
In mining rear axles for parts, I've found a few thrust washers like this.
But more often they have been in little pieces or completely gone.
I call it the ignore that noise and keep driving school of Model T maintenance.
As noted above, the Ford imprint and part number in the grease groove indicates the washers were die cast under pressure, no doubt the process requires a lead alloy much different from bearing Babbitt. Great picture Steve, thanks !!
By the way, was it a thrust washer failure that led to the destruction of the brake shoe?
FWIW, the 1915 parts book lists bronze thrust washers. (!)
I wonder when they went to Babbitt ?
I am finally in a place to get my T pictures.
This is what my Babbitt thrust washer or what was left of it looked like.
Rich, yes. When the thrust washer goes away it often causes brake destruction like that, typically on the right side. It allows the axle shafts to slip leftward, and the hub nuts do the rest. Sometimes people miss it because the damage isn't that drastic (yet) and they attribute the nut-to-brake contact to some other cause.
I was very fortunate in that I had a Model T expert to guide me and this forum about which to lurk for a year before I made my purchase. -I therefore knew enough to only consider those cars whose rear-ends had been modified with bronze thrust washers. -No way was this newbie going to tackle a problem like that right off the bat.
For the rest of us who end up with a Ford of questionable differential pedigree, the problem looms large because it appears that a good deal of fairly heavy, space-consuming equipment and specialized toolsónot to mention mechanical knowledge and skillóare needed to fix the problem and let's face it, most of us just don't have those kinds of chops.
The question, then, become one of where to go for help. -Model T mechanics are few and far between, and with a problem as significant and widespread as this one, the Model T community needs some kind of clearing house that can recommend affordable and qualified service centers to which we can go for this kind of help.
Yes, that's a problem for a great many people. In many parts of the country it can be addressed by getting into a local Model T club. But the question makes me think of our friend Tony in Staten Island. I facetiously told him he should move to Kansas, but I really don't know of a solution where there's no club within a reasonable distance. I suppose in such cases you have to find a good local shop with experienced mechanics who may not have Model T expertise, and provide them with the applicable books and a list of Model T parts dealers. But for an engine/transmission rebuild the best course is probably to put it on a pallet and send it off to an experienced Model T specialist.
Pig in a poke, if you don't know, tear it down you will probably find it needs attention anyway. Good learning experience, don't trust your life to not knowing. KGB
With very few tools and help from MTFCA books and this forum I rebuilt my rear axle. There is no local club around me. This is my experienced team of model T experts. The worst part was cleaning the tubes.
Frank, it won't happen in your 1915 tourer, because it already did when I test drove it for the Dr Verschoor. That was the first time I had experienced it. We were on the flat, having completed a U turn, and next thing there was a clatter from the diff as the throttle was applied, the pinion gear teeth riding over the crownwheel teeth.
Your diff has bronze thrusts!!!!
Allan from down under.
The ugliness looks more like chemical reactions and less like wear. At some point the stuff just up and crumbles into dust . . .
Fred, thats about what mine looked like. Very little holding one of them together.
Does anyone else have pictures like Fred? Pictures as you guys have pulled apart the pumpkin. Would like to see the other side of the ring gear assembly.
Willis is that what you wanted to see?
This thrust washer looks really new but if you look close it has a crack all the way through.
This thrust washer looks really new but if you look close it has a crack all the way through.
Yes, thank you. It is hard for me to tell but, is the ring gear okay or not? What all did you do in the rebuilding besides the thrust washers?
Here's a pic of one the thrusters from the 18's rear axle here.
There wasn't enough of the other one to photograph. About 6 miles and it just pulverized.
The axle had been worked on in the late 70's, put back together and never ran until 2016.
I agree with Rich B. about the washers being diecast. I have thought for years the "Babbitt" thrust washers were made from something much different than bearing Babbitt, it just doesn't make sense that they are so fragile if they were made from Babbitt. There have been all kinds of theories on why they fail, from the wrong lube to acid that builds up in the rearend. I don't buy any of that, there have been too many NOS washers that shattered when dropped on a concrete floor or broke some how before being installed. I also don't buy the "myth"(JMHO) that common gear lube will "eat" bronze washers. I have seen too many three and four speed transmissions with bronze synchronizers, Eaton two speed rearends for trucks with bronze shafts in them, bronze ring gears in winches and gear reduction boxes, etc., etc. that used nothing other than common gear lube and never had any problems with the lube. That being said, I am in no way claiming to be an "expert", just my observations of being around and working on things mechanical for the last sixty years and not buying in to the "hype". I'm sure someone will prove me wrong, but that's OK. I'm from MO., you'll just have to "show me". Again, JMHO.Dave
If you look up the thrust washers part #2528 through the years in the parts books, they start out as babbitt then listed as composition and the later books as metal.
In late 1916 Canadian books change from babbitt to bronze, maybe that's a replacement part but not a production part? as I've pulled down several year spans in Canadian diffs and not found bronze ones.
I agree. Die cast. Probably some form of pot-metal. I don't believe that the problem with them has anything to do with oil or use, just time/age.
Pot metal is usually zinc or at least has a lot of zinc in it. Zinc will react with muriatic acid. Just as an experiment, if anybody has an old thrust washer and muriatic acid laying around, put a drop of it on the thrust bearing and see if it fizzes. Lord knows old pot metal castings deform and crack with age. That may be exactly what's going on with thrust bearings.
Since it's a bearing, it's probably not the same pot metal formula that typical die cast parts are made from, but I'll bet you're correct on the zinc content.
Maybe some home chemist will do the test!
David, I'm no expert either, and you are correct that there are all kinds of gearboxes with bronze components. Seems these days, "common gear oil" ain't so common any more. A number of lubricants in different weights now state they are not for use in gearing that contains bronze parts.
If push comes to shove, we'll probably start seeing threads on gear oils that will be as much fun as the ones we've had on motor oil !! ; )
Do you recommend non-detergent gear oil?
Ha ha ha, Jerry, here we go ! Probably should start another thread. Only recommend I have would be to avoid gear oil that is not recommended where there are bronze parts involved !
Well, for those who get so worried about no zinc in their oil, maybe they should refrain from swapping to bronze. I'M KIDDING. I'M KIDDING.
If I had an old one, I'd do the muriatic acid test. I've got the acid, but no bearing. I've done this before when sorting scrap "lead". Lots of times, zinc items get mixed in with lead items. Zinc will contaminate a lead melt. Not good. On the positive side, a lot of pewter (tin) gets mixed in with lead scrap. I like getting tin for the price of lead.
In my stash of used parts I have a pair of thrust washers that are almost certainly cast and machined babbit. They show no signs of the greying, cracking and general deterioration exhibited by the Ford thrusts. I have been tempted to use them on more than one occasion, but went to bronze to avoid having to do the job over again.
Perhaps an enterprising T'er could manufacture some for a test, but then again they are not likely to be as economical as the bronze ones supplied by the vendors.
Allan from down under.
Willis, I had to replace the ring and pinion due to rust pits. I believe it sat in water at one time. You can see in the one photo I posted above the lube looks like chocolate milk. I also used the fun projects pinion bearing. New drive shaft bushing and replaced one axle with good used. Replaced all hyatt bearings with good used ones. All new thrust pins also. It was pretty bad. The guys on this forum made it easy to understand. I dont know how to post the link from my rebuild thread. It was last janurary. It has all the photos of what I found.