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hi all,
i'm still reconditioning my m47. i pulled the old m47 front countershaft bearing out (p/n 1209392) without pulling the shaft out, which was easy without a puller. After that, i was ready for a machine shop to cut a groove in my new bearing for the clip the old bearing has. the new bearing, nu304 ecp, is the same in all respects as the original, nla bearing but without the groove for a clip.
i contacted 3-4 machine shops asking if they can cut a groove into my 2 new bearings (one as a spare) which they can use the old bearing as a template.
i didn't receive a reply from any of them. so, i decided to use my old, still-good condition, original bearing but with the new bearings and cage. i did check on the inside of the old bearing and it's in fine condition, reusable.
i would prefer to use the new bearing, but i can use this "rebuilt" bearing for now and maybe cut the other new one, later.
the bearings are easy to remove from their polyamide, pliable cage. the cage is a smaller diameter than the bearing, so it can be easily removed and dropped in.
i took some photos to show that something can be done about nla bearings with a polyamide cage.
here, i'm removing, pushing out each bearing carefully using a small flathead screwdriver. i don't want to scratch or mar any of the new bearings.
next photo shows all the bearings and the cage out of the new bearing.
final check of the old bearing, front back and the inside and dropping in the new cage in it after the check.
here, popping in the new bearings, easy because the cage is not brittle.
my "new," now available, volvo in-stock, "skf" bearing. finished with the new skf bearings and cage in the old outer bearing with the clip already in place. i couldn't find any bearing name on this old bearing, front or back, strange. i'll use the money i saved to buy a case of good cold beer for this texas heat.
regards,
byron golden
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Hi Byron,
I didn’t realize that you had lost those cages out of both bearings!
It amazing that the shafts turned as well as they did.
I bet that transmission was really noisy at any speed or even idling.
I’m happy for you being able to get them off the shafts too.
I wonder where the heat came from or what it was that took those babies out!
I was only taking a good look onto the main input shaft and tried to count the balls.
I did see the ten rollers of the countershafts bearing but it just didn’t dawn on me that it was in the exact same condition as the top bearing.
The top bearing is the working horse in the scheme of things and it’s up out of the oil by comparison to the countershaft.
I’m curious on how the shield is fitted. On the shaft race or the outer race.
Does it protect or hold the oil in the bearings lower half?
I wonder if this transmission should have had slingers installed in the design.
It’s why I have used a friction modifier with my ATF for the last 100 K. A 20% additive concentration may have helped my 1991 stay together or its the way I drive it?
When I was chatting with you about the ball bearing, I was interested in how many balls were in them?
The more balls the better, is my thinking, as they should support heavier loads.
These bearings are called “filled” or have filling slots to add a few more elements.
But there are compromises to beware of, When they build these upgraded series to fit into the same dimensional place.
The slot does take away some support in that area and can make a bearing slightly more noisy.
This is because it is cut into the upper side edge of the race groove it can limit applications to heavier loads axially but to be used at slower turning speeds. I have seen where it pays to upgrade.
I’m sure that that engineers and “bean counters” help make the decisions on what to put in these transmissions.
Like you said earlier, it may have been substituted, if it was rebuilt before you got it.
I’m still not sure if there wasn’t two or more hands involved in producing these gear boxes.
Just a suspicion. (:)
Does that box or any others you have a Volvo name casted on the right side?
You said August of 1990. I suppose you found a number code and decrypted it?
I have to admit you are an adventurous type to take apart a new bearing and try a used race.
I would have never tried that but I wouldn’t be shy at cutting a ring groove it I had to either!
Of course it have to be setup and ground in with an abrasive cutting wheel or at least a carbide groove tool.
I suspect that the shops would not wanted to disappoint you. They would have to charge a rate to “break in to a job” or plan a this job around standard production.
That is the game changer anymore, as it’s hard to find shops that will do “one off” manual machining!
The change over has to cover labor, no matter how they are setup to do something simple and most any bearing will be far cheaper.
On some equipment though, the replacement of a unit may out way all costs.
I can’t say that the use of stand off rings are purposeful, but I’ll bet it started with an engineer painting himself into a corner,
In order to save his buns, he went into the realm of specialty designing himself out of an oops!
In Another language it’s called “cost overruns.”
Once that’s done on government contract, it gets “locked or spec in” as the only way to make it! It becomes the only way it will be excepted on all future parts or assemblies.
One comes to my mind,
A ton of paperwork to change a careless or ridiculous notation of dimensional tolerances applied to a radius of a corner on a wing tip of a guided missile. Yikes from me, as “It’s just fits out there, in the wind!”
Military specs do numbers on everything!
Ok that all I’ll say and await you enchanted posts!
Phil
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Hi Byron,
I see you are progressing nicely and that puller made that happen. Ouch on the cost though.
It must have been a long reach, in more than one way! (:-)
I hope you plan on doing more than one transmission with it.
So did you ordered that $250 bearing you spotted or did you come out better using the Tasca connection?
The NTN bearing count seemed a bit low as I couldn't see under the shaft and the amount of space above it seemed to be large.
You did mention that you thought the main one was replaced.
The countershaft has ten and its within a far smaller diameter bearing.
I surely hope the one you ordered has more balls and hopefully some other features inside to control some possible axial movement. I don't see the use of a wave spring used in electric motors.
I'm curious about the guts of this assembly, especially with failures.
Since the main shaft is in two pieces and rotating at two different speeds, I'm concerned with the aspect of a light preload being or staying constant within the aluminum case size.
Temperatures make changes of its own length.
The distance between the lay shafts radially is very minimal and is adjusted as backlash.
It is interesting about heat melting the cages, or my other thought of disintegrated from a chemical reaction of the oil attacking them?
Then the question goes to, why not all of them?
The main input bearing just might be an economy version on what should be in the region.
I have been noticing that a "feature change" within bearings can make a price double, just because?
I cannot speak over NTN being being bad or what country as bearings are made everywhere.
I can say we have fewer bearing makers in this country than we should have just for national security. This has happened over many decades with global interaction.
Brand names are built on reputations and a lot of it depends on the quality of materials for sure!
But importantly, the right bearing design in the right place counts even more!
This has always been a tickler with me and that is, in most all specifications within table listings, the number of elements is not disclosed.
What other way can you change the "main loading characteristics" of a bearing!
Like how many logs do you put under a house to move it?
Surely the price reflects a lot of possible value and we hope it's not just marketing for profits.
Pictures in catalogs are very generic in nature and is it exactly be what you are getting?
Lots of times they show the shields or seals to hide what's in there.
I don't like being treated as, What, I'm not suppose to think, can things be better. Duh?
Side by side, I can count what's a light version is over a heavier duty version within a same series or same sizes of a bearing. Tell me, cause enquiring minds want to know!
Where do get that information, except with suffixes noted on each bearing, that can get faint.
I truly understand you wanting the right replacement!
Doing your own work surmounts into a nice learning curve with greater dividends!
If that bearing was changed out of there, so was the information! Dubious, very dubious of rebuilders or part houses in competition.
There are so many that don't do pictures and somewhat understandably for each and every bearing, but for us lay people, everywhere, we need to have a way to call up the insides more easily.
I keep looking for what should be free education and not hoarded to only college boys!
SKF seems to be the hardest to work with in extracting information as their site is somewhat redundant and glossy, IMHO.
NTN was more easily sorted through and informative but so far but understanding suffixes and worth in cost is challenging.
I'm still finding cracks in the armor! (:-)
I have worked with several engineering folks, as sort of a liaison and those guys had gobs of catalogs but more importantly, they have contact numbers, right into the bearing manufacturers representatives or other engineering.
Don't ask me, where in the heck I got the idea that ten elements works best for a better bearing design.
Guess it came to me During my learning process of asking questions of elders getting answers with a mutual respect that is earned.
I call all,of this, "a rule of thumb law" that seems to prevails in among engineering challenges and then they, the "engineers," work back and forth from there!
Believe it or not, no one is a know it all!
I would like to know if there is a "filled" bearing is used here, in this application, that is most likely rare but available if you plug in the right suffixes.. Maybe it's the $250 bearing?
Production numbers effect everything in the business, especially economically.
Someplace that bearing is used elsewhere!
I know what you are saying about military specsifications, if you know that it's what you want, but how many know that SAE doesn't mean the same thing, for a few more taxpayer dollars?
Research is research just who is paying what, to whom, when?
Our students pay universities tuitions and they show them the ropes through the classes.
The students work their brains, to make different twisted ropes and then the university, holds and sells the patents!
What a game!
It continues on the job, let me tell you, except I made good wages, that in turn that sent the career I loved, overseas! Offer is, move over there or change! No thank you and our country has slipped away in manufacturing towards information and guest services only!
Hello virus!
Talking about kneecapping the post office, go back 35 years with fast tracking of NAFTA and the Perot debate!
Good on ya' and your transmission!
Phil
Phil
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hi phil,
yeah, pricy bearing puller, but i prefer paying that than pulling the shafts. i'm concerned about misalignment when reinstalling. i put the puller down as a special tool, rarely used in the tool kit. i may have to go back in sometime.
what is special is it thin and flat enough to fit in the bearing groove and pull it out.
the volvo bearing was about $50, about the same for skf bearing. i would go either way, but i ordered some additional parts from tasca, so i bought that, too. that $250 bearing won't fit, but it's getting close to the price to have the machine shop to do its work.
the input shaft bearing has 7 bearings. i didn't want to look or change anything. i figured engineers designed it that way.
i found no play in the shafts radially or axially. however, on the output shaft, i need to check for how well the shim fits, as instructed by volvo.
about the melting of the cages, it's very curious, and important to follow. i haven't worked with gears long enough to have any ideas. i asked myself why hadn't the rear bearings been affected, especially the rear bearing with the polyamide cage. not a scratch. i have a photo of that. my thinking is that the heat was rapid and dissipated quickly. obviously, the high heat didn't transfer all the way to the rear shafts, or hot enough to cause any visible damage.
good point about information on load bearing, well, bearings. i understand about a cover and not knowing what's going on with the bearing, but i just buy bearings from reputable mfrs and try to avoid chinese counterfeits, they are out there.
and about skf sites on bearings, they don't even give complete info on the bearing dims, they leave part of it blank! i have to go to this one site, called something like bearing dimension (name on my other computer), which gives the dims. one skf site does show the inner and outer diameter of the bearing based on the cylinder or ball bearing. that helps.
i do have an skf site that shows the bearing prefixes and suffixes which helped, considerably. i purchased the bearing with the removable inner race with that info.
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non-topic discussion
keeping the mfg base here, prices would have to rise. so consumers would have to pay more. the employees suffered, not the consumers who are not employed in mfg. i think nafta is workable, but surely, it could be modified. i'm not familiar with all the details, but it should have a provision on options to either retrain for another career, vocational or otherwise, or pay for college, even a two-year school. i think trump's chucking the whole nafta deal was not necessary. i'm sure that mexico and canada would renegotiate it. things change in 15-30 years.
the first major company that started buying chinese is, of all things, walmart. i remember when sam walton was alive, his theme was be american, buy american, made in america. after he died, his family started buying, en masse, products from china. after that, the floodgates opened up. i saw some statistics that buying from china kept, was it inflation down or economic growth up, a percentage point, two or three. but it had real, tragic consequences, and back to your point, mfg moved overseas. now, if one exports more than takes in, the trade balance would be in your favor, but in trade, there are trade-offs, lower prices, lower inflation, but more unemployment? it's a two-edge sword. china is building huge trade agreements and with trump cancelling our tpp (trans-pacific partnership), it wiped out our opportunity to have a huge trade group without china, but now, that's flipped. bad news. the worst part, trump did it in spite of obama, not based on its merits.
anyway, some rambling. getting back, i'll see if i can get those bearings cut "economically," otherwise, i'll install that bearing and get moving on the reconditioning after the parts arrive.
thanks for the valuable info, phil.
byron
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hi phil,
yes, i'm not sure where the heat came from. it could come from the driver when the car hit something very hard (bent control arm) and burned up the clutch somehow. The rear bearings are in excellent condition and show no effects of heat.
i inspected the input shaft bearings, and again, the bearings show no signs of wear but only with the cage melted. yes, both cages melted.
there is no shield on the bearings, and the bearings certainly only go in one way. the cage is from the new bearing. before i install it, i'll rotate the countershaft bearing to see its roundness.
about the bearing count, 7 for the input shaft bearing, i figure the original ball size and count is designed for a particular load; i wouldn't upgrade but get the exact bearing.
about the box, i didn't see volvo's name, but the part number, i'll look more closely.
standoff rings are fine as long they don't become obsolete, as this bearing has gone. bearings with clips are still out there. for example, oem bearings for the rear input shaft bearing with clip are still sold. just not this front countershaft bearing.
a machine shop i contacted said they could do it, but it's a $300 minimum, too prohibitive.
milspecs are important because it's a threshhold of minimum quality. one can be confident about the mfg process when the item meets milspecs.
thanks,
byron
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Some trivia: Volvo began as a spin-off of sorts from SKF, the company that invented the self-aligning ball bearing. SKF's global headquarters is still in Gothenburg, Sweden.
A note on nomenclature, the bearings you refer to have inner and outer "races" in which the rolling elements ("rollers" or "balls", in the case of your M47) turn with very little resistance.
I would suspect that the heat came from the bearing itself, not the clutch. The bearing failed, friction ensued, creating heat. For this reason I suggest careful inspection of that outer bearing race you intend to reuse. FWIW, I can see nothing wrong with the race, as pictured, from where I sit. However, even tiny surface defects/roughness can cause high pressure spots that push lubricants away. Premature fatigue, welding and eventually abrasion and failure can result.
Thanks for sharing your progress and best of luck,
Will
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XC60 / Odyssey
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hi will,
thanks for the insight. i'm reluctant to reuse a bearing race, but it's based on expediency. i received a reply on a minimum cost from a machine shop: $300.
i ran my finger on the inside and it's smooth. i'll put it on and rotate it to check for roundness.
a person mentioned a machine shop with a $100 minimum. i haven't received a reply, yet. i think $100 for cutting two bearing grooves is looking like a good deal.
i'm familiar with the volvo story and interesting that a ball-bearing mfr spun off a car mfr.
up to now, the bearing and cage replacement was just a test to see if i could do it, but if i can't find a machine shop to cut the grooves "economically", then i'll go with using the older outer race.
i'm shocked that i didn't see any bearing numbers on the rim, but the heat may have removed them. they're not etched in. it's obviously a volvo bearing (skf) with that groove.
i'll check that machine shop with the $100/min and do the two, new bearings, but if not, i'll install it and wait for my other bearing and some parts from Tasca.
although available, the volvo input shaft bearing has to ship from sweden. i opted for volvo from tasca even though this bearing with groove is available from skf and other mfrs.
thanks,
byron
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Hi,
I was thinking over about the swapping of bearing parts.
Did you only use the cage out of the new bearing?
I think that will be fine to do, as long as You inspected it most carefully for any kind of color change on the rollers and definitely for spalling of anything anywhere!
Phil
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hi phil,
yes, using the new cage. i'll test for roundness while on the shaft before i install it.
i have a new puller tool ($185) to pull off the front input shaft bearing, and now waiting for the bearing from tasca (part coming from sweden).
at least i won't have to pull the shafts out. 4 of six bearings (2 new) are good, and i'll check the last two after i finished the front bearing install. i'll have to pull off the rear housing.
of course, the real test is driving it, which it'll be a while. i'm not pulling my aw70 when it's doing fine--it's really a mess doing a tranny job.
thanks,
byron
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