failed transmission needle bearings

[pat in Santa Cruz]

In the last year, I have torn down a few transmissions with disintegrated needle bearing cages. Last week, I tore into my own, which also had failed needles. They have 40,000 miles on them, oil was changed regularly, they were never run dry. In each case, the needles either wore into the cage until they dropped out in domino fashion, or the cage wore until the bars holding the cage together fell out and the ends fell off, loosening all the needles at once.

I don't recall seeing so many failures before in such a short time. I am wondering if the bearings we are getting now are inferior to what we were getting five years ago. They certainly are inferior to original Ford bearings, which have substantially stronger cages.

There are two types of needle bearings: ones with pins on the rollers that ride in holes in the cage. The other have the pins set in the cage, and bores in the needles. The first type fail when the cage wears a small bit until the swage on the pins that hold the cage together fails, and the cage falls apart.The latter type wear into the cage until they release.

In both cases, the cage seems to be made of inferior steel that wears quickly. Are these from China? Are there stronger bearings available? The cost of the bearings is nothing compared to the work involved replacing them.

here are 2 photos, one of each type.

IMG_2118 by tiopato2000, on Flickr


IMG_2115 by tiopato2000, on Flickr

[Tom Wesenberg]

I can't answer your bearing question, but I put a small powerful magnet in each fill and drain pocket in the plugs. It's amazing the amount of fine metal grit they collect, and this should help the life of the bearings.

[Joe K]

I have rebuilt transmissions using a bearing instead of the "spacer" that fits between the short and the long bearing. I can't remember now but I think two longs and a short fill the entire length of the cluster gear.

But that may not help the failure mode you have going here. Two bearings or three, it's still going to wear the cages and cause failure.

Joe K

[29 Tudor]

I just opened up the transmission in my '29 and found the roller in the input shaft was in pieces. It was an original Ford bearing with the spiral grooves but I was surprised at the wear on the spacer washer. I can see how there is (slight) thrust to the rear toward the spacer and given that the cage for the rollers is NOT rotating at shaft speed, I can see how there is wear but I was surprised at the amount.

I have considered trying to find a needle thrust bearing to replace the spacer. Anyone done that? Seems like that would be a much better arrangement. I don't know if needle thrust bearings were available in Henry's day.

SD

[Marco Tahtaras]

I agree that the quality of the bearings is certainly suspect. However I think it also raises the question of gear lube. Have any of these transmissions been running STP?

[Fred]

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Originally Posted by Marco Tahtaras

I agree that the quality of the bearings is certainly suspect. However I think it also raises the question of gear lube. Have any of these transmissions been running STP?

Marco, Why do you ask that ?? .. I have always put about 1/2 can in any trans. I have rebuilt with no problems yet.. Got one ready to go as you read this, should I not use it ?? Fred..

[Purdy Swoft]

I had problems with straight STP as gear lube and don't recommend it. A little STP shouldn't be a real problem but may not shift as well. Thinner gear oil works best for me.

I've also used three bearings in the cluster gear and eliminated the spacer.It seemed like a good idea at first but not anymore for me .. When the bearing fails, the loose needles tend to stack and alter tooth alignment.,Complete failure of the transmission soon follows. The spacer between the bearings in the cluster gear will hold the gears in alignment better when bearings fail. An extra bearing in the cluster gear is just another bearing that can fail and needles stack up. Usually when the transmission starts to fail it will happen when shifting into second gear. If you can get it into high (third gear) you can probably make it home. Third gear is direct drive. I've made it home before with all of the gears broken and the bottom of the transmission and reverse idler knocked out.

[d.j. moordigian]

Originally Posted by Marco Tahtaras

I agree that the quality of the bearings is certainly suspect. However I think it also raises the question of gear lube. Have any of these transmissions been running STP?

Yep !

I'd rather use a GOOD set of used needles....!!

As far as STP is concerned, as an engine builder, it's not a lubricant...

[H. L. Chauvin]

Hi Pat,

In thinking about all of the past Model A questions & comments on Model A transmissions, there may be several reasons for extreme "wear" & "failure" of transmission needle bearing.

However, "all" of these problems appear to be possibly associated with one (1) cause.

For example, totally "ignoring" Fords "Great" little "Model A Instruction Book" that came with the car, that most ignore because maybe it was written by some old gray haired authors who never saw a TV, never saw a computer, never had power windows, turn signals, power brakes, back up lights & air conditioning .... besides using telephone books for toilet tissue because of the Great Depression.

So in our World of highly automated atomic human electronic geniuses, we ignore this little book written by supposedly idiots and:

1. We press in the clutch, take off & rev up to 15 - 18 mph in lieu of 5 mph, don't let off the accelerator, don't pass through neutral as recommended, then grind away into 2nd gear with a roar that could wake up a 90 year old deaf neighbor at 8:00 a.m.

2. Then switch to 3rd at 27 - 29 mph in lieu of 12 mph, don't let up on the clutch, & grind away into 3rd to wake up his 87 year old deaf cousin down the block at 8:01 a.m..

3. This grinding noise is manufacturing iron particles to be mixed with transmission oil to act like gritty valve grinding compound.

4. Next as mentioned above, as modern day DNA chemist who add sulfates to our wine to promote early death, we do not use Ford's recommended gear oil.

5. We add pure non-recommended non-lubricating STP, non-recommended light weight gear oil, or maybe Hub Oil as thick as chicken manure siting in the sun for (3) days.

6. In addition to Mr. Tom W's wonderful magnet trick to collect iron particles, one major difference in "back then" & today is that our ancestors had faith in Ford's Model A Instruction Book as opposed to trying to form a new 21st Century Religion on how to shift & care for a Model A transmission.

7. Years ago, in the military, at red light intersections, when one heard an inexperienced young military jeep driver grinding manual transmission gears, the normal comment from military sergeants was:

"Hang in there son, next year we are making your gears with rubber."

Even inexperienced military women drivers in military hospitals back then could shift jeep manual transmissions -- as usual, women follow instructions.

Sincerely hope this helps.

[Fred]

I also think a big problem is the input shaft is worn on the inside surface & at the pilot bearing end & causes all to be out of alignment and this puts added pressure on the little brgs..

[Purdy Swoft]

Originally Posted by Fred

I also think a big problem is the input shaft is worn on the inside surface & at the pilot bearing end & causes all to be out of alignment and this puts added pressure on the little brgs..

I agree, an input shaft worn on the inside surface and at the pitot bearing end would shorten the short front input shaft needle bearing life and would also cause it to jump out of high gear.

[ursus]

The transmission I recently dismantled had a failed needle bearing as pictured in the original posting - all in pieces. The input shaft bearing pocket was deeply brinneled, almost as if the needles were spinning in place rather than rotating around the main shaft. Otherwise, the input shaft had hardly any wear and looked to be fairly new NOS Ford (as did all the gears).

I am looking to find an alternative bearing in order to salvage the input gear. I looked for modern caged or jacketed needle bearings that would overcome the problem of having a brinned inner race surface. It looks like the options available would require at least two such bearings plus a sleeve to take up the difference as moderne bearings are in 0.250 inch increments and Model A needle bearing has 0.375 inches of "space" to fill. I wonder if anybody here has a suggestion?

[Purdy Swoft]

H.L. , You make some strong points there in post # 9. Fords great little instruction book has some important info. A lot of the info is out dated but many try and follow them to the letter. I always felt that shifting out of low gear at five MPH and shifting into high gear at twelve MPH is ridiculous if not down right DANE-JUS !!! smiley face. If we pulled out of the driveway and did a creepy take off like that, Something might come around the curve or over the hill and run over us. We've got much better roads now days than they did in the day the great little instruction book was written. Times have changed, we've got lots of traffic .

While the recommended gear oil worked in the day, I think that we have better choices today.Lighter gear oils work very good for me . People that don't have experience with straight cut gears are liable to grind them at times An experienced model A driver can feel the gears without grinding and when the gear speeds equalize glide right through the gears with never a clash. This is most important when taking off down hill. If you lolly gag between shifts going down hill the wheel speed will quickly get ahead of gear speed and will cause a really bad clash.

My dad was in Pattons Red Bull division and he gave me lots of pointers on shifting gears.You are right on about some women. Deb still works in a hospital and she can shift model A gears as well as I have ever seen.

[Rocketsled]

Assemble journal roller bearings with some Moly Assembly Paste, which is 50/50 oil and Molybdenum Di-Sulphide mixture. Same stuff that is applied to the camshaft and cam followers before starting a rebuilt engine. Add Moly Gear Oil Additive to your
gear oil of choice and you will be good to go.
Journal roller bearing failure in the A transmission due to inadequate lubrication can cause rear axle shaft breakage, and wheel loss!

[Purdy Swoft]

I don't mean to be disagreeable but nothing about the transmission can cause axle damage and wheel loss. You must be thinking about something else.

[pat in Santa Cruz]

to address some questions and commentary:

I never use STP. I don't know about the two transmissions I rebuilt, they were just given to me withotu any opportunity to interview the owners.

I have driven crash boxes since I was 15. I do not grind gears unless the car is an unfamiliar one. After a short learning curve, I don't grind them either. The gear teeth look almost NOS.

the input pilot is exactly to ford spec.

I used the "600w" sold by most vendors until I discovered it foams up too much for my liking. That stuff might have STP in it. Then I switched to Omala 680. I slightly suspect the foaming might have interfered with the lubrication, but the stuff is really clingy and hard to remove even when whipped up. Years ago I used Shell Valvata, and did not have these problems, but I still suspect faulty manufacture.

The amount of wear on the outside of the cages, which wore into the swaged pins that hold it all together, was barely noticeable. I believe the swage and assembly of the bearings are inferior to what we were getting several years ago. My trans was rebuilt with a NOS cluster, new bearings and good used gears and shafts in 2007. The large main shaft ball bearings are in excellent condition. I heard a funny sound and suspected the needles on the trip back from Grand Canyon last year. Subsequently I tore it down after letting it sit more than usual until I had the time. The needles are all in good condition, none are ground up like the others were. Those transmissions were driven relentlessly until other trouble ( cracked babbitt) caused the entire driveline to be disassembled as long as the engine was being rebuilt.. So in the case of my box, there were little if any metal shavings. The rollers that wore into the cages obviously caused some metal fines, but I change the gear oil every 2000 miles, so that got rid of some of them, unless they were embedded in the clinging slime that the "600" made.

In many other cases, I have noticed the needle pins had worn the cage holes much larger. The only needles I have retrieved in the last 5 years from well driven cars that did not show alarming wear have been older replacement stock with thick cage ends. Right now I am restoring a pickup that was used by a rock hound in the desert for 50 years. There was so much dust in the rear axle that it was caked up above the gasket ring on the banjo. The transmission needles are in well used but good condition. They are original Ford needles. I think we should be looking for better bearings. In the mean time, I'm going to add moly additive for more lubricity.

[H. L. Chauvin]

Hi Pat,

Your reply # 16 adds a lot of common sense information. Thanks ever so much.

Thanks also for taking time for first photos, descriptions, & words of caution.

I had an old original transmissions that appeared to have lasted forever -- still have it stored.

Now I guess that all of us that bought needle bearings & rebuilt transmissions with "new" needle bearings within the past few years will be ..... well ..... "living on pins
& needles".

Think I'll try to concentrate on types of crankcase oil and/or whitewall tires to avoid getting high blood pressure.

[Rocketsled]

It would be hard to imagine such an outome, but it has happened. Seizure of a roller bearing causes the the gears to lock and the axle to stop suddenly. The wheel continues it movement and shears off the axle at the taper.
This happened to a friend and I rebuilt the rear axle and transmission, which was locked.

[H. L. Chauvin]

Hi Rocketsled,

Thanks for the "Heads-Up" comment.

1. With the information provided thus far on "new" transmission needle bearing failure & results from same; &,

2. With those of us who know we have "new" transmission needle bearings;

3. Looks like limited mileage Model A Insurance Companies will not be overly concerned about Model A drivers driving excess miles with their "new" transmission needle bearings.