'77 850-T3 Transmission Input/Output Bearings

[n3303j]

This came out of the 5 speed transmission on my 850-T3. I'm looking for a replacement.
Bearing is marked SKF, 3205, ITALY, 2. This just indicates a light duty double row angular contact bearing.

This bearing (photo) has 14 balls per row and is assembled through a "fill slot".

All the replacements I see are 9 balls per row. That would make them light duty.

Is the 9 ball an acceptable swap for the 14 ball?

[Antietam Classic Cycle]

I wouldn't use the 9 ball, especially if they have plastic cages. You'll want to find 3205 AC3 IIRC. I bought some from Pete Roper.

[pete roper]

For some reason, (I have no idea why?) the 3205 AC3 type used in pre-'84 gearboxes seem to be very hard to find in the US. It's weird, I can get them just down the road in Canberra, usually overnight, and tend to keep a couple on the shelf as I still do a fair bit of 5 speed work.

The later bikes use 3205 ATN9 bearings with a phenolic cage and nine balls per race, these are slightly higher speed rated but also lower load rated and although either will theoretically perform the task the ATN9's are undeniably more fragile.

Pete

[n3303j]

It's the designation that is making me nuts.
3205 A/C3 is a C3 internal clearance bearing. It is sold in both an 18 ball and 28 ball configuration. The 28 ball unit has fill slots in the inner and outer races.

I've also seen the ....N9 bearing in 18 and 28 balls.

I'm used to the bearing number describing every unique aspect of the bearing. Size, clearance, shielding, mounting grooves etc. This particular bearing seems to ignore the standard labeling conventions.

I have sourced the ones I want, but it was by product images combined with the basic 3205 product number.

[Antietam Classic Cycle]

It's the designation that is making me nuts.
3205 A/C3 is a C3 internal clearance bearing. It is sold in both an 18 ball and 28 ball configuration. The 28 ball unit has fill slots in the inner and outer races.

I've also seen the ....N9 bearing in 18 and 28 balls.

I'm used to the bearing number describing every unique aspect of the bearing. Size, clearance, shielding, mounting grooves etc. This particular bearing seems to ignore the standard labeling conventions.

I have sourced the ones I want, but it was by product images combined with the basic 3205 product number.

Care to share where you've sourced the 28 ball bearing?

[n3303j]

https://tinyurl.com/ya7mghgf
https://www.123bearing.com/bearing-3205-SKF.php

Couple of choices, not counting eBay.

https://tinyurl.com/yauswhjv
Counting eBay.

[Wayne Orwig]

Avoid the 9 ball with plastic cage.
Dilliw found a good source in the US. I'll search for it.

Found the old email. Maybe something in here will help you find a good bearing.

In the U.S. there are two stocked bearings that are better alternatives to the 3205 ATN9 (9 ball plastic cage) bearing found in the 5 speed transmission.  One way to find “unobtainium” is to find a friend in the same boat.  In this case the U.S. guys with the 70's/80’s Husky kickers have to source same bearing and these are their two main options.
 
ZKL 3205 New Force C3 is the old design, 14 ball with a serpentine metal cage.  There is good quantity of these on the ZKL US website and you can find them in distribution for $20-$25 each.  Czech made (maybe).
 
 http://www.globalindustrial.com/p/motors/bearings/angular-contact-bearings/3205c3-nf-double-row-angular-contact-c3-irc
 
 
SKF 3205 E/C3 and MRC 5205M C3 appear to be the same bearing (they are the same company).  It’s a 13 ball, max fill c3 with of a  newer design using a metal cage designed for  high speed applications.  I got them here (not the quickest ship) for $72/each.
 
https://www.mrosupply.com/bearings/angular-contact-bearings/double-row-angular-contact/2069123_3205-ec3_skf-bearing/
 
It's anyone's bet as to if the newer design is worth 3X the price but that's what I bought.
 
Source:
http://www.cafehusky.com/threads/on-your-crank-bearings.45145/
 
 

[Antietam Classic Cycle]

https://tinyurl.com/ya7mghgf
https://www.123bearing.com/bearing-3205-SKF.php

Couple of choices, not counting eBay.

https://tinyurl.com/yauswhjv
Counting eBay.

Thanks! Found the first source myself after searching a bit and was on 123 Bearing's site but hadn't found those. 

[acogoff]

     Please let us know what shows up. From experience, what shows up doesn't necessarily match what is promised. Out of frustration, I ended up using the 9 ball metal caged skf explorer in my T3 and it seems to go down the road just fine, but for how long?

[n3303j]

I'm pretty sure what will show up is the item I want.

In these ambiguous situations I get a verbal or written confirmation that the product matches the supplied photo. Probably end up with the expense part from 123bearing. They will work directly with you over the phone.

At age 72 i only need to do this job once to have a lifetime guarantee. Box only has 60K miles on it to the best of my knowlege BUT one day it made some odd noises and the oil was full of aluminum powder. Bought a spare box with a broken shift spring from eBay. Fixrd it and put it in the bike and threw the original one in a corner for a couple of years. Finally have time on my hands. Found a couple of the rollers from the throwout bearing in the bottom of the box. Figured one (or more) of these found their way into the speedometer drive worm. Lost a bit of that worm and the area aluminum was chewed a fair amount. Surprisingly the speedometer never stopped working.

(PS: Looking for someone who has one of the worms around who doesn't hold it too dear.) Otherwise I have to buy the whole assembly for a premium price.
Thanks

[pete roper]

I'm pretty sure what will show up is the item I want.

In these ambiguous situations I get a verbal or written confirmation that the product matches the supplied photo. Probably end up with the expense part from 123bearing. They will work directly with you over the phone.

At age 72 i only need to do this job once to have a lifetime guarantee. Box only has 60K miles on it to the best of my knowlege BUT one day it made some odd noises and the oil was full of aluminum powder. Bought a spare box with a broken shift spring from eBay. Fixrd it and put it in the bike and threw the original one in a corner for a couple of years. Finally have time on my hands. Found a couple of the rollers from the throwout bearing in the bottom of the box. Figured one (or more) of these found their way into the speedometer drive worm. Lost a bit of that worm and the area aluminum was chewed a fair amount. Surprisingly the speedometer never stopped working.

(PS: Looking for someone who has one of the worms around who doesn't hold it too dear.) Otherwise I have to buy the whole assembly for a premium price.
Thanks

If nobody near you has one I'm pretty sure I have a couple knocking about.

Pete

[Wayne Orwig]

Found a couple of the rollers from the throwout bearing in the bottom of the box. Figured one (or more) of these found their way into the speedometer drive worm. Lost a bit of that worm and the area aluminum was chewed a fair amount. Surprisingly the speedometer never stopped working.

(PS: Looking for someone who has one of the worms around who doesn't hold it too dear.) Otherwise I have to buy the whole assembly for a premium price.
Thanks

Send me a PM on Monday or Tuesday when I get home. Let me know how many teeth yours has. I have a couple of different ones laying around. I assume you mean the one that drives the cable, not the one inside.

Not sure how anything would get past the double row bearing to get in there though. Odd.

[n3303j]

<SNIP>
Why do the bearings have to be Loctited in to the case ? (unless I read that wrong somewhere)

I assume the manufacturer thought of Loctite as a cheap "guarantee". I also read about Loctite for transmission bearing installation. The last two 5 speeds I opened had Loctite on the bearing including the output that is retained by a plate with 3 bolts. There was enough Loctite applied that it blocked the lower bearing oil bypass slot.

Interesting aside. I just gutted a T3 dustributor to replace the two sealed bearings. These bearings were also installed with Loctite.

Guess it doesn't hurt to install a low expansion  (steel) bearing into a high expansion housing (aluminum) with the added security of an adhesive.

[pete roper]

Do NOT install any of the gearbox bearings with Loctite of any sort! If you look at the cases you'll see the 3205 bearings are retained by locking plates and require no Loctite but more importantly the needle rollers have oil galleries in the outer races and cast into the case. If these are filled with Loctite the bearing will fail very quickly from lack of lubrication.

Pete

[n3303j]

A transmission rebuild page from the Moto Guzzi factory service manual:



...just saying.

[Chuck in Indiana]

I've also seen a torque spec of 20 foot lbs on an M6 bolt in the service manual.. sometimes common sense should prevail with Guzzi manuals. <shrug>

[pete roper]

A transmission rebuild page from the Moto Guzzi factory service manual:



...just saying.

Well don't say, think.

If the needle rollers in particular are loose in the case, (And they do have a tendency to walk.) then they can be centre punched into position. The 3205's, unless the bores they are going into are flogged out and I've only seen that twice in 40 years, will be retained more than adequately by the plates. Loctite the plate retaining screws by all means but not the bearings themselves.

One presumes that if one were to use a Loctite or similar product it would be a bearing mount. The whole purpose of this stuff is to fill up space! If it gets into the bearing races themselves or the oil feed galleries and solidifies, (Which is what it is supposed to do.) it will not only impede or block oil flow but also lock rolling elements causing damage to themselves and the races in which they run.

Loctite is NOT a good idea in this situation. It doesn't matter what the wretched book says.

Pete

[RoyRogers]

Does this mean the bearing set from HMB containing two FAG 9 ball per side with flimsy plastic cage input/output bearings are better replaced ?

No need to replace those..they are OEM as of 1975 onwards.

[Chuck in Indiana]

No need to replace those..they are OEM as of 1975 onwards.

Uhh, yeah, they need to be replaced if you are there.. or especially if you are running synthetic lube in the transmission.
Uh oh.. here comes an oil thread..

[kidneb]

Does this mean the bearing set from HMB containing two FAG 9 ball per side with flimsy plastic cage input/output bearings are better replaced ?

I wouldn't bother replacing those, see no reason for it. Michael Behrendt at HMB knows his onions and has only had good experience with these 2x9 ball bearings which are not the same as the old, prone to break, plastic cage ones -   http://hmb-guzzi.de/Caged-ball-bearing-input-output-shafts-5-speed-gearbox
HMB,- by the way,- does not like the metal cage ones - http://hmb-guzzi.de/Amazing-Finds
I have renovated a few 5 speed boxes and always used the pre `85 OEM 2x14 ball metal cage ones, but I would not hesitate on using the FAG ones from HMB if I were to.

No one ever spoke of using Loctite on the little needle cage bearings with the delicate oil galleries on the input shaft end and the mainshaft front, as far as I can see, not even the Guzzi manual.
I will, however, keep on using Loctite on the outer race of the roller bearing on the front of the layshaft(output) as the manual prescribes. I have, a couple of times, experienced that race coming loose, and you wouldn't want that.

[pete roper]

No need to replace those..they are OEM as of 1975 onwards.

They are OEM on every five speed from about 1984. The earlier bikes all uses the 14 ball per race bearings and these had a much, much lower incidence of failure than the 9 ball per race bearings. In my career I've probably seen two cases of the early type failing but failures of the later type are legion!

I'm sure the main reason for the change was cost, not because of any physical or performance benefit. I'd never bother replacing an ATN9 with another one, it's just reinstalling a known weak point.

Pete

[RoyRogers]

They are OEM on every five speed from about 1984..
Pete

I must have false info on that one, my speci could have meant 1984 .

Just gut my newly repair (72 850GT) transmission back, with a ninerbearing. It will survive me for sure.

[normzone]

" Loctite is NOT a good idea in this situation. It doesn't matter what the wretched book says. - Pete "

NGC: You just brought back a memory - just after the turn of the century I was attempting to get a manufacturing outfit I was working with to consistently use thread locker on fasteners in ruggedized computer equipment, except for on cover hardware.

I laced the manufacturing floor with small, subtle signs with slogans such as:

" Girls go for guys who use loctite "
" Loose screws sink ships - use loctite "
" Loctite is your friend "
" Loctite - Learn it, live it, love it "

[kidneb]

But Pete,-weren`t the failures of the early 9 ball per race bearings solely due to the plastic (phenolic as you call them) cages breaking or dissolving or whatever, caused by synth oil or not ?
Isn't it appropriate in this discussion to recognise that the material of the new 9 ball per race bearings is of a very different and modern material ?
HMB calls them TVH-type,- I don't know what that means, but they sure are different from the old ones ? 

          Ben

[pete roper]

No idea about the ones HMB sell. Why would I experiment when I can get ones I know are fine here?

[jacksonracingcomau]

No idea about the ones HMB sell. Why would I experiment when I can get ones I know are fine here?

Yeah, my grandad�s father said that about the bicycle, thought it wouldn�t catch on, horse worked.

Might, possibly, be the everlasting bearing, not that I have a problem with any of em.
Problem appears after parking it seems, park at your peril, bearings like to spin, maybe these can sit still for longer ? Rewrite the rules,, things change, once they just span.

[n3303j]

This is what 123bearing sent. Pretty much exact duplicates of the original even to the country of origin (Italy).
Took them a couple of weeks and they were almost $60 USD each. But this is probably the last pair I'll ever need.

[Chuck in Indiana]

Problem appears after parking it seems, park at your peril, bearings like to spin,

I had a Chevy van that taught that to me..

[Antietam Classic Cycle]

This is what 123bearing sent. Pretty much exact duplicates of the original even to the country of origin (Italy).
Took them a couple of weeks and they were almost $60 USD each. But this is probably the last pair I'll ever need.