R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 11-09-2002, 05:22 PM   #1
Tech Apprentice
 
Join Date: Nov 2001
Posts: 67
Angry Tamiya Ball Differentials

Hi guys,
Just wont to post a message telling you my experience with the TA-04r diffs.I was rebuilding it my car, and managed to lose 2 of the little diff balls. Anyway my local hobby store didn't have the regular 3mm balls, only the upgraded onces which were way overpriced.

Anyway me being the cheap person i am found an alternative, i went to a ball bearing shop and bought some 3mm ball bearings extremely cheaply ! I was happy with them, but after 3 runs the diff was tight. I pulled it out, and when i spun it around it was extremely rough, and not smooth like they usually were. I thought this isn't right and went to Hobby shop for advice, and they said "yeh gotta use tamiya only, etc buy this and this. Oh yeh and this is a good product as well". Ended up buying the 3mm balls for it, put them in with some team assocated grease, same problem. Very jagged, and isn't smooth,

i can't think why it could be ?

The ball bearings are fine. The pulley shouldn't have any effect on it should it? I called the Hobby shop, cause i live 2 hours away from them and they adviced i buy the the D-rings for em and it should fix up the problem. What do you guys reckon? I didn't think the rings would make it that rought. I look at them, and there is slight line where the balls have been running. But other then that nothing too bad.

Can anyone advice me what i should do?


This lesson probaly taught me not to take shortcuts and buy non tamiya products.
My first rc car, so i'm still learning right?
(it makes me want to sell my car and buy one with a non-ball diff )

Anyway, Thanks in advance for your suggestions/comments.

P.S how do you determine when the diffs are tight enought?

Last edited by taybelZ; 11-09-2002 at 05:24 PM.
taybelZ is offline   Reply With Quote
Old 11-09-2002, 05:40 PM   #2
Tech Elite
 
Join Date: Jan 2002
Location: Wisconsin
Posts: 2,246
Trader Rating: 49 (100%+)
Send a message via AIM to weaponx
Default

the problem is not that you did or did not use tamiya products. i dont beleive it is the diff balls or diff rings i am willing to bet that your problem is the the ball thrust bearing. the ball thrust bearing (also known as thrust washer) carries the majority of the load in the diff assembly and is what usually causes the gritty feeling in the diff. you may want to look into replacing the ball thrust bearing.
weaponx is offline   Reply With Quote
Old 11-09-2002, 06:56 PM   #3
Tech Apprentice
 
Join Date: Jan 2002
Location: Lakewood, CA
Posts: 69
Default

I recently had a problem that I thought was a rough diff, but it turned out to be that I was tightening the wheel nuts too tight. If you are using the stock plastic hex hubs, when you tighten the wheel nuts too much, it forces the plastic hex hubs into the bearings and causes it to feel notchy and rough when spinning the wheels. You can replace the plastic ones with the aluminum ones which don't have the over-tightening problems.

I've run non-Tamiya ceramic diff balls on my TA04R without any problems.
underdog is offline   Reply With Quote
Old 11-09-2002, 07:20 PM   #4
Tech Elite
 
Join Date: Jan 2002
Location: Wisconsin
Posts: 2,246
Trader Rating: 49 (100%+)
Send a message via AIM to weaponx
Default

the way i adjust my diff. i hold the left tire in my left hand and the right tire in my right hand and with my right thumb i try to move the spur gear. if the spur gear moves tighten until you can no longer move the spur with your thumb. this should be very close but the track is where final ajustments should be made. hope this helps and good luck
weaponx is offline   Reply With Quote
Old 11-09-2002, 11:22 PM   #5
Tech Champion
 
SpeedTech's Avatar
 
Join Date: Aug 2001
Posts: 6,028
Trader Rating: 5 (100%+)
Default

Hi taybelz,

I will try my best to help you with your problem, but of course without the car in front of me, it is difficult but here goes:

First check what underdog was mentioning about the hex hub. I've seen this happen on underdog's car and even after the diff rebuild, it was still jagged like you were mentioning, and I think we solved his problem by putting on the aluminum hex hubs from the 414M series.

If you're convince that it is the diff, then usually, as other have mentioned, it is the thrust bearing that gets griddy first. Because it is such a small bearing handling a lot of torque and load, and also being more outside, it tends to accumulate dirt and grease faster. Simply blast it out with some motor spray and put some grease back into it. I personally like to use AE black grease on the thrust (although Tamiya have you put the same diff grease on the thrust and diff balls). I put a tiny tab on the diff screw where the thrust bearing assembly will sit on, then put on the thrust bearing. I put a coat of black grease around the thrust bearing and work it into the balls inside the thrust washers. Then finally I put a small dab on top of the thrust bearing assembly (the side that will go into the diff outdrive first). This should ensure a very small thrust assembly.

For the diff balls and diff rings, I put a light layer on the diff rings as I put them on the diff outdrives, and then I fill each whole of the diff pulley where the diff balls sits with a bit of the diff grease (for the diff ring and balls I use AE diff grease, which is different from the black grease earlier). Then I set the ball in there and gently press them in with my fingers.

As you bring the two diff halves together, make sure the diff rings are seated properly on the diff outdrives (on the TA04, the diff rings are notched to match up on the outdrives). Sometimes they will move right when you are putting the diff assembly together. A small dab of diff grease on the outdrive before you put the diff ring on will help stick it in its place.

Once you get the diff together, keep turing the diff screw until the diff halves are against the diff pulley. The diff should not be tight yet. From here, every 1 turn or so, work the diff back and forth a little bit (rotate the diff halves) keep doing this until you lock the diff (don't over tighten, or you'll snap the plastic t-nut on the other side) and back out the diff screw 1/4-1/2 of a turn, and you should be okay. Lastly, take a Q-tip and clean off any excess diff grease or black grease (these grease attract dirt and dust very quickly) and...You're done! Sounds long, but after you do it a few times, you'll be able to rebuild diffs very quickly and smoothly

Since it was your first RC car (welcome to the hobby by the way ), I hope the information above will help you. Those of you on the board that would like to add and help out, feel free to do so....those of you that fell asleep because of my long post I'm terribly sorry...hehehehe.

Thanks

Steve Wang
Speed Tech R/C
www.speedtechrc.com
SpeedTech is offline   Reply With Quote
Old 11-10-2002, 07:04 PM   #6
Tech Apprentice
 
Join Date: Nov 2001
Posts: 67
Default

Sorry about the late reply guys, been very busy with uni exams.

Anyway thanks for the all the reply guys.

I gave the thrust bearing a good clean and applied some wd-40.
It feels a lot smoother tho its not 100% smooth. I'm still unsure why this is so, also i dont' have any "plastic hex hubs" on my diff.
I looked at the manual... perhaps you are refering to diff housing plate?

Dave
taybelZ is offline   Reply With Quote
Old 11-10-2002, 07:06 PM   #7
Tech Addict
 
icon's Avatar
 
Join Date: Feb 2002
Location: Boston
Posts: 527
Send a message via AIM to icon
Default

glad to see good advice from you steve. we know your busy with speedtechrc. just wanted to say kudos to you.

BTW: the hex he means is the hex where the wheel/tire mounts onto.
icon is offline   Reply With Quote
Old 11-12-2002, 05:01 AM   #8
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,865
Default

Taybelz - I hope you're not using WD-40 as your only lube on the thrust washer - what I do when rebuilding diffs is thoroughly clean all the balls, plates and gears with motor spray, pack the thrust washer as much as poss. with Asociated black grease (or similar), and then use enough stealth lube (or similar) to coat the main diff balls. This results in smooth diffs. If you've cleaned all the diff parts, lubed them properly, set the diff right, and you still have a rough diff, that indicates wear or damage.
sosidge is offline   Reply With Quote
Old 11-12-2002, 08:13 AM   #9
Tech Champion
 
SpeedTech's Avatar
 
Join Date: Aug 2001
Posts: 6,028
Trader Rating: 5 (100%+)
Default

Hi Icon,

Thanks, I try my best to find the time to get involved on the board

Steve Wang
Speed Tech R/C
www.speedtechrc.com
SpeedTech is offline   Reply With Quote
Old 11-12-2002, 09:28 PM   #10
Tech Fanatic
 
rccarracer's Avatar
 
Join Date: Oct 2001
Location: Sydney, Australia
Posts: 926
Default

Quote:
Originally posted by sosidge
Taybelz - I hope you're not using WD-40 as your only lube on the thrust washer - what I do when rebuilding diffs is thoroughly clean all the balls, plates and gears with motor spray, pack the thrust washer as much as poss. with Asociated black grease (or similar), and then use enough stealth lube (or similar) to coat the main diff balls. This results in smooth diffs. If you've cleaned all the diff parts, lubed them properly, set the diff right, and you still have a rough diff, that indicates wear or damage.
I'll do the same thing with my diffs...
I'll put almost too much grease on everything, and on the first run all the excess is thrown out of the diff.....
Never had problems with the diffs on my cars....
Also make sure you do rebuild the diffs regularly, means a longer life and better performance.
rccarracer is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tamiya Ball Diff Set limbohz R/C Items: For Sale/Trade 1 04-28-2008 01:24 PM
WTB: Xray M18 Adjustable Ball Differentials!!!! Refujiado R/C Items: Wanted to Buy 0 10-07-2007 01:35 PM
Viscous Differentials Versus Ball: Racing Information? oXYnary Electric Off-Road 2 01-09-2007 01:28 AM
WTB: Tamiya TA05 Differentials TwinKays R/C Items: Wanted to Buy 3 06-16-2006 04:21 AM
HPI Ball Differentials for PRO 2 skiptomylou6 R/C Items: Wanted to Buy 1 09-11-2003 05:01 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 04:02 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net