RC10 - A Stamp Rebuild - Chipped Idler Gear

[GreenBar0n]

There are a few reasons that any well built trans will not spin for the purported 15 seconds.

Friction from the felt seals
And more notably the grease in the bearings.
Also excessive side play in both the idlers and out drives that can cause the gears to wobble.
With the felt seals removed and all of the grease removed from the bearings, only lightly oiled, a trans may spin for maybe, maybe 15 seconds.
When spun with compressed air at a very high rpm it is more likely to spin for 15 seconds or longer. BTW it doesn't appear as though any mention of how the trans was spun.

I have built many 6 gear transmissions with no thought to time spent.
I have spent hours meticulously deburring, sanding, polishing, aligning, spacing, critically reducing excess tolerance, degreasing , lightly oiling, breaking in and readjusting.
I have never had a trans spin for 15 seconds by merely spinning by hand. Yet they regularly run as quiet as a belt driven trans, nearly silent. Zero notchy feel, zero excessive friction and a very very smooth feel.

Just my 2 cents

Chuck

Thanks for that! Have you also done the pinned diff ring mod, is that worth doing?

[GreenBar0n]

In 2013 I built up a completely stock rere trans and didn't touch the gears. This was assembled with the stock bushings not bearings. When under load bushings are far less efficient but as far as the spin test went, it was miles ahead of the original 6 gears.

Not sure why Jim would say it should spin freely for 15 seconds, if it weren't true at the time. I wasn't able to get your YT link to work.

[GoMachV]

yeah the youtube embedding isnt working, i edited with an external link. Not much to see, but you can tell its smooth and thats what is important. Oiled bearings vs greased will make a HUGE difference. We are running chinese $1 a pop bearings these days vs the $80 high end NMB bearings sets back in the day.

[radioactivity]

GreenBar0n

Have you also done the pinned diff ring mod, is that worth doing?

A couple of my cars do have pinned diff rings. I did run them in the 80's and 90's.
But I also ran CA glued rings

If I were racing today I would probably have pinned rings. It's just a little insurance.


Chuck

[GreenBar0n]

yeah the youtube embedding isnt working, i edited with an external link. Not much to see, but you can tell its smooth and thats what is important. Oiled bearings vs greased will make a HUGE difference. We are running chinese $1 a pop bearings these days vs the $80 high end NMB bearings sets back in the day.

Thanks, I understand. Your spin rate and revolutions, are about what I get with the 40th's.

[XLR8]

... We are running chinese $1 a pop bearings these days vs the $80 high end NMB bearings sets back in the day.

That's true and the difference is night and day.
I have some of those early metal shielded bearings and they're still smooth and spin forever.
By contrast, I've had to replace many of the modern cheap bearings from Avid - even those with rubber seals.
You get what you pay for.

[RogueIV]

There are a few reasons that any well built trans will not spin for the purported 15 seconds.

Friction from the felt seals
And more notably the grease in the bearings.
Also excessive side play in both the idlers and out drives that can cause the gears to wobble.
With the felt seals removed and all of the grease removed from the bearings, only lightly oiled, a trans may spin for maybe, maybe 15 seconds.
When spun with compressed air at a very high rpm it is more likely to spin for 15 seconds or longer. BTW it doesn't appear as though any mention of how the trans was spun.

I have built many 6 gear transmissions with no thought to time spent.
I have spent hours meticulously deburring, sanding, polishing, aligning, spacing, critically reducing excess tolerance, degreasing , lightly oiling, breaking in and readjusting.
I have never had a trans spin for 15 seconds by merely spinning by hand. Yet they regularly run as quiet as a belt driven trans, nearly silent. Zero notchy feel, zero excessive friction and a very very smooth feel.

Just my 2 cents

Chuck

I have a feeling that time was a typo.
Even the transmission in my B6.4 running on ceramic bearings doesn't spin that long even with the trans mounted and wheels fitted. I ditched the felt seals on mine as I'm not running on dirt and that frees it up quite a bit.

[jcwrks]

The Jim Halsey guide says the entire 6-gear assembly should spin freely for 15 seconds after doing the steps in the guide.

First, I'd see if you can get a good 5+ second spin when you have the assembled drive gear & idler assembly in your hand. If not check the gear mesh. You can enlarge the hole in the spine plate for the drive gear pivot (one with the nut) a smidge so that you can get a perfect gear mesh. Skip the black grease on the thrust bearing. Make sure the RH gear on the diff tube is aligned and not skewed a bit.

[juicedcoupe]

Things to keep in mind:

Not all bearings are created equal. Not by a long shot. Most RC bearings are actually on the cheaper side of the spectrum. I've paid $20+ each for some of the bearings in my fishing reels.

Not all bearing oils are created equal, especially when trying to get something to spin freely.
- There are also lubricants that just leave a film on the bearing surfaces.

The amount of oil used on a bearing makes a difference.
- A minimum amount of thin oil will provide better "free spin" while offering minimal protection.
-Saturating the bearing will sacrifice "free spin" for increased protection and bearing life.

I say to keep these things in mind because of maintenance. Those thin oils and low drag shields also require increased maintenance and some of them aren't easy to get too.

Bearing shields type makes a difference. And the more protection it provides, the more drag it has.

[Dangeruss]

Some good thoughts on RC bearing quality and oil types.

Some good videos on RC bearing quality and oil types.


Bearing Tests:



Oil Tests:

[GreenBar0n]

Now I want to find the expensive NMB bearings, and use light oil . Thanks guys!

I'll still go ahead and do everything in the Halsey guide, why not, I'm in no hurry on this one, just want it to be the best it can be for an old RC10; I also like the idea of having it race ready, even though I may only take it around the yard once or twice.

[juicedcoupe]

For my fishing reels, I make my own mix of TSI 321, Corrosion X, and 99% IPA. It's mostly alcohol as a carrier fluid.

I flood the bearings in it and let the alcohol evaporate, leaving a thin film of TSI and Cor X.

[Dangeruss]

For my fishing reels, I make my own mix of TSI 321, Corrosion X, and 99% IPA. It's mostly alcohol as a carrier fluid.

I flood the bearings in it and let the alcohol evaporate, leaving a thin film of TSI and Cor X.

99% IPA?? How many beers in before you forget there's a bearing sloshing around the bottom of your pale ale??

Glug...Glug...

[GreenBar0n]

For my fishing reels, I make my own mix of TSI 321, Corrosion X, and 99% IPA. It's mostly alcohol as a carrier fluid.

I flood the bearings in it and let the alcohol evaporate, leaving a thin film of TSI and Cor X.

99% IPA?? How many beers in before you forget there's a bearing sloshing around the bottom of your pale ale??

Glug...Glug...

That is strange how they call Isopropyl alcohol, IPA, instead of IA.

[GoMachV]

Oh no ... I've been using beer too