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View Full Version : 3 speed tranny's and ball bearings... NOT recommended?


WhiteWolf McBride
11-04-2011, 01:38 AM
Guys:

I've been told that it is NOT recommended that you put ball bearings in the stock Tamiya three-speed tranny's. I scanned the forum, and could not find any evidence of this 'advice', and also scanned Tamiya's 3speed forum, and nada there either.

Am I being fed a load of crap? I'd appreciate it if Joe and Willy could chime in, as they are people I know, and I respect their advice. I will accept other veteran advice too... aka, from the Yahoo Group days.

If I've missed the 'thread' about this discussion, I'd appreciate a link to it.

Respectfully,
WhiteWolf

Claus
11-04-2011, 02:18 AM
When I had a King Hauler I installed ball bearings in my transmission and never had a problem, then I read where guys say you should not do this because the bearings do not slide on the shafts like the bushings. Mine worked fine with the bearings but I'm not saying it's the right thing to do either.

Lil Giants
11-04-2011, 04:43 AM
I've got trks with bushings & bearings in the trans, I don't remember anymore which is which, I've never had a repair to any of them.

Bearings are an unnecessary exspense, bushings work fine, use the kit supplied grease during assembly, I never grease them again after that. The only areas I add bearings is in the outer ends of driven axles (next to the differential is bushed), axle pinions & front non powered wheels. Everywhere else is bushed.

FreddyGearDrive
11-04-2011, 08:14 AM
Leave the bearings at the hobby shop! If you plan on useing the truck in water elements. Have a truck that I use for keeping my walks clean.Well half way through the season,the truck sat for two weeks because there was no snow.Came time to use it again & it wouldn't move!:eek:
Turns out that the axle bearings had rusted up tight.
Never used a bearing again in my drive lines.
If you want to see something kool,take one of the tamiya bushings & heat it with a torche.You won't believe how much oil will come out of them. The bushings are self lubricating.As they get hot they release oil.
That's why they last so long.
As for the trany,Claus is correct.If you install a bearing under the 2-3 shift hub,it's just a matter of time & it can give you trouble.
A hardened steel bearing sliding on a not so hard main shaft will lead to trouble.
I purchased a high milage used truck a few years ago,that was always run in first gear.He had the hold clips on the shift rail to stay in first.
when I tore the truck down & removed the shift locks,the shift shaft was almost locking in one position & didn't want to slide any further.
Turns out that the bearing had wore a groove in the main shaft from the bearing always riding in the same place. It was only a couple of hundred thousands,but just enough to mess with the shifting of the trany.
This is just what I've run across since being in this hobby.
FGD

Claus
11-04-2011, 03:21 PM
Speaking of 3 speeds, has anybody used this transmission, is it any better, lower gears or just higher priced?
http://store.rc4wd.com/3-Speed-Full-Metal-Transmission-Black_p_830.html

fhhhstix
11-04-2011, 05:53 PM
I also agree with Freddy leave the bearings out and save some money you don't need to spend.


Speaking of 3 speeds, has anybody used this transmission, is it any better, lower gears or just higher priced?
http://store.rc4wd.com/3-Speed-Full-Metal-Transmission-Black_p_830.html

Yep I have one and I would not recommend it to a friend. First it is a pain to shift I ended up using a HiTec 645MG servo to shift it. Second it is an all wheel drive trans but the shaft for the front wheels is only powered in first gear.

Silver version.

http://i574.photobucket.com/albums/ss185/brokenb4/Black%20dump%20truck/100_0136.jpg

Travis

WhiteWolf McBride
11-05-2011, 06:46 AM
Well...

Thats 2 for, 2 against, but one of the 'for' votes holds considerable weight for me. Especially the way he treats his trucks (thats respect Joe, hokay?)

And I don't intend to go wading with my beasties, and they get torn down regularly anyway. I'm a guy who knows how to tear a metal-shielded bearing down, clean and re-lube her, and put the shields back so ya can't tell they was ever apart. Been doing it for over 2 decades, as back in my days of offroad buggy racing, it was considered regular maintenance! Then again, so was cleaning a keyboard, and replacing monitor display tubes!

Thanks, and yea, I know about the bushings, aka 'oilites' as the industry calls them. One thing we did learn back then - use the plastic ones for placeholders when ya paint, nothing more. Seen a set ruin a buggy front axle & rim over a day of racing... oy. Oh, and good for shelf queens too.

WhiteWolf

doodlebug
11-05-2011, 08:07 PM
Hey Travis, how's 1st gear in that tranny for tractor's & off road?
Or would adding a gru be better? Just curiuos.
Later, Neil.

coligny
11-06-2011, 09:07 AM
being a synchromesh gearbox the bearings are not on the elements supposed to slide. so I don't see how steel on steel wearing of the shaft could make a problem...

So honestly... i'd battle against drivetrain drag as a first priority. As for waterproofing...be generous with the gunky silver antiwear grease between all the shelling parts...