R/C Tech Forums

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

Like Tree4Likes
Reply
 
Thread Tools Search this Thread
Old 04-08-2013, 01:03 PM   #301
Tech Adept
 
D.Martijn's Avatar
 
Join Date: Jan 2011
Location: Belgium
Posts: 217
Default

Quote:
Originally Posted by TeamT View Post
Hi guys,

I am hoping someone will be able to help me with a problem I have.
Firstly, thank you to Racer 53 for your diff rebuild videos. They are excellent. I've subscribed to your channel.
I've just gotten back into RC after a 25 year break. To get back in I bought a T4 second hand. The owner told me he had just re-built the diff.
When it arrived I fitted the electronics and went for a drive. It turns out the diff had never been set.
So I set about stripping out the gearbox as the diff was built with the cover over the head of the thrust bolt, which I removed then re-assembled. I then followed the videos to set the diff. I just could not get it right. It would be fine a few minutes, then loosen right up. After a few re-tightens I realised I had the diff the wrong way round (head of the bolt was on the left, looking. From the rear).
I then stripped the entire thing and re-built it as per the videos.
I struggled quite a bit with getting it right in terms of how tight and I think I was virtually at the bottom of the spring. If I look at the plastic T nut holder for the thrust bolt it seemed like it was really being pulled concave a bit. But if I put screwdriver shafts to hold the diff outdrives (outdrives?), if I really twisted hard I could move the diff, but only just and I really had to twist hard. I backed off the bolt a little bit, then re-assembled everything (the right way round this time).
I then set about doing the run-in. As I was getting to the end of this I heard a pop and saw the T nut holder had shot out and hit the dogbone (this was the pop sound). I opened up the opposite side where I saw the head of the thrust bolt had snapped off.
So, I started again from the beginning, went through everything as above. I ended up getting the same result only this time a little further into run-in.

There was another symptom I noticed. When the gearbox was assembled but out the car, when I twirled the shaft that the slipper and spur attach to it wasn't completely smooth. It felt like every 1-2 turns there was some imperfection that the gears had to roll over. I can't see this affecting the diff, although I don't know enough to tell.

I'm a bit at my wits end. I don't know what I'm doing wrong. My sense of it is I'm over-tightening the thrust bolt and the pressure is simply ripping the head off.
I'm now out of thrust bolts so will have to get more.
Are there any pointers anyone could suggest. I really want to get this right.
Maybe I should start with a really loose diff then tighten up? I think I'm starting too tight.

Thanks for the help.
In what condition are the diff rings? Are there deep grooves?
I've had this once, snapping the head of the boltů
If the rings are grooved very badly, buy a diff rebuild kit and some new 3/32" big balls for the diff.
And rebuild the whole diff as the video or the T4 manual suggests.

Clean all the gears with a toothbrush and some motor spray, look carefully for some imperfections on the teeth of the gears. if this don't solve the problem, maybe it's time to change all the gears. that might solve the imperfection,
D.Martijn is offline   Reply With Quote
Old 04-27-2013, 08:01 AM   #302
Tech Addict
 
turners dad's Avatar
 
Join Date: Nov 2011
Location: Joplin, MO
Posts: 530
Trader Rating: 41 (100%+)
Default

This may have already been covered but I missed it.
I had been rebuilding my sons diff after every weekend. Doing everything as recommend and the different were so smooth in the beginning of the day.

This is for a 2wd not 4wd........

A couple weeks ago we were racing and a team driver noticed my son was on his side and hitting the power trying to roll the car back on its wheels. He yelled out to me "that diff is toast", well he was right, the truck would shoot to the right on the gas and to the left on the coast.
Later he explained to me that the diff can't take the extreem pressure of full throttle and one wheel not turning.

He is absolutely correct, I have not had to rebuild a diff since he explained this to me and my son.

So in other words "wait for the marshal to flip you back on your way" your diff will thanks you!
__________________
Team Bendy!!!
X Factory X60 - X's 2
X Factory X6▓ - X's 3
X Factory SCX-60CF
X Factory SBX-60CF
turners dad is offline   Reply With Quote
Old 05-26-2013, 02:22 PM   #303
Suspended
R/C Tech Elite Subscriber
 
Join Date: May 2013
Location: Chandler, AZ
Posts: 1,235
Trader Rating: 23 (100%+)
Default

Very helpful thread. Copied it into my RC computer to help me out at the track
__________________


Airtronics - Carburant Racing - EZ Customs - 92zero Designs
Team G Racing is offline   Reply With Quote
Old 05-31-2013, 05:32 PM   #304
Tech Master
 
RCBuddha's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2003
Location: SoCal
Posts: 1,929
Trader Rating: 35 (100%+)
Default Does anyone else...

Does anyone else sand their thrust washers?
RCBuddha is offline   Reply With Quote
Old 06-01-2013, 05:14 AM   #305
Tech Addict
 
turners dad's Avatar
 
Join Date: Nov 2011
Location: Joplin, MO
Posts: 530
Trader Rating: 41 (100%+)
Default

Quote:
Originally Posted by RCBuddha View Post
Does anyone else sand their thrust washers?
How would you hold them to do it? I guess with your finger tip? I just flip them then toss'em
__________________
Team Bendy!!!
X Factory X60 - X's 2
X Factory X6▓ - X's 3
X Factory SCX-60CF
X Factory SBX-60CF
turners dad is offline   Reply With Quote
Old 06-01-2013, 08:18 AM   #306
Tech Initiate
 
xdrex's Avatar
 
Join Date: May 2011
Location: SOCAL
Posts: 36
Trader Rating: 4 (100%+)
Default

Quote:
Originally Posted by RCBuddha View Post
Does anyone else sand their thrust washers?
I do. And yeah, I just use my finger tips and move the washer around in a circular motion on some fine sandpaper
__________________
HPI Sprint 2 Drift
HPI Blitz ESE
HPI RS4
AE B4.1
Heli-Max 1SQ
xdrex is offline   Reply With Quote
Old 06-01-2013, 10:03 PM   #307
Tech Adept
R/C Tech Elite Subscriber
 
Join Date: May 2013
Posts: 101
Trader Rating: 20 (100%+)
Default

Quote:
Originally Posted by xdrex View Post
I do. And yeah, I just use my finger tips and move the washer around in a circular motion on some fine sandpaper
Good idea
rc32 is offline   Reply With Quote
Old 06-07-2013, 01:38 PM   #308
Tech Rookie
 
Join Date: Feb 2013
Posts: 13
Default

I got the TLR kit & installed the Ball Diff kit on my xxx-sct

I snapped the screw on the first one from over tightening & I did better with my second 1 & had it last me a few months....& then that 1 snapped to but lasted way longer

I'm gonna be installing my 3rd ball diff now & have gotten better at it....word of advice to all new ball diff user's/installers don't get frustrated, it's gonna take a lot of trial & error to perfect them.

Losi has a YouTube channel & has a nice install Video & how to break it in....it's about 4-5 minutes long & is easy & Helpfull
hairmetal is offline   Reply With Quote
Old 06-11-2013, 12:13 PM   #309
Tech Initiate
 
Join Date: Oct 2008
Location: Belgium
Posts: 34
Trader Rating: 1 (100%+)
Default

wrong topic, delete this answer please.
crashingbird is offline   Reply With Quote
Old 06-21-2013, 05:27 AM   #310
Tech Apprentice
 
Join Date: May 2008
Location: Evil Empire
Posts: 60
Default

Guys, pls. help me to find the right setting for my diff.
From one hand, there is a rule "tighten until you can't move the gear with your hand while holding 2 outdrives", from other hand, AE setting rule is "tighten fully then back 1/8 turn"
My issue is that there are 1.5 turns between the settings, ie if I tighten until I cannot move the gear, I still have to tighten 1.5 turns more to get to the AE setting.
Is this normal? Which setting should I use? I know it's a matter of personal preference, but still...
Toyman is offline   Reply With Quote
Old 07-29-2013, 12:57 AM   #311
Tech Apprentice
 
Join Date: May 2013
Location: So. Cal.
Posts: 56
Trader Rating: 5 (100%+)
Default

Quote:
Originally Posted by RCBuddha View Post
Does anyone else sand their thrust washers?
Yep...as has been recommended to me.


My trick for holding them is super slick. I use the back a toothbrush handle and fix some servo tape to hold BOTH washers at the same time. This serves two purposes: one, it's fast...and two, it helps to hold the washers flat.

Try it!
__________________
Associated: B4.2 FT, T4.2 FT
XRAY: XB4
MUGEN: MBX6R
Old School Memories: RC12E, RC1O GoldPan
CaptainGizmo is offline   Reply With Quote
Old 08-09-2013, 06:46 PM   #312
Tech Rookie
 
Join Date: Aug 2013
Posts: 1
Default

That sounds great! Thanks for sharing those great resources.
__________________
Find the best professionals for [url=http://implastics.com.au/]plastic injection moulding in Brisbane[/url] to trust with your plastic prototype or with your injection moulding work
redotten is offline   Reply With Quote
Old 08-09-2013, 08:05 PM   #313
Tech Fanatic
 
Join Date: Jul 2012
Posts: 871
Trader Rating: 25 (100%+)
Default

Quote:
Originally Posted by Toyman View Post
Guys, pls. help me to find the right setting for my diff.
From one hand, there is a rule "tighten until you can't move the gear with your hand while holding 2 outdrives", from other hand, AE setting rule is "tighten fully then back 1/8 turn"
My issue is that there are 1.5 turns between the settings, ie if I tighten until I cannot move the gear, I still have to tighten 1.5 turns more to get to the AE setting.
Is this normal? Which setting should I use? I know it's a matter of personal preference, but still...
I built a few of these. In fact I am still using one that I built from February and it is just now starting to need to be rebuilt. that is racing 1 a week with a few practices in between.

I have a xxx-sct and because I blew up two prior to this current one I am using we tightened all the way down then backed 1/8 off. Broke it in, then tightened a little more, and then ran it and I check it after every other race for tightness and pull the ball diff out to check the gears after every few race days. I also like my diff a little tighter, could be because I am afraid to blow it out again LOL. Another good tip is you never want to stop at the loosening...you want to have it set during the tightening. In other words if it says to back it out an 1/8, I will back it out just a little more then the 1/8 turn, then tighten it up to the 1/8th where it would stay.
tfrankito is offline   Reply With Quote
Old 09-05-2013, 11:52 AM   #314
Tech Elite
 
W.E.D.Jim's Avatar
 
Join Date: Oct 2001
Location: Kissimmee,Fl.
Posts: 4,927
Trader Rating: 17 (95%+)
Send a message via AIM to W.E.D.Jim
Default

Racing on and off for nearly 30 years I have tried it all.

Setting the diff in your hand, holding the outdrives with two flat screwdrivers while spinning the gear with your fingers is a great "baseline" starting point. Your fingers should hurt a ton trying to slip the gear this way if it's close.
I have tried dozens of greases, different techniques for sanding and prepping the rings and thrust washers, nothing works better then having the slipper slip before the diff does!
If the slipper has to be really loose to slip first, the diff is too loose. You should be able to force the slipper to slip on the work bench, before the diff. You'll know because the spur gear will turn, but not the top shaft/adjustment nut. If the top shaft turns the diff slips first.

Tips: adjust the diff bolt close, turn the diff outdrives and gear to work them in each half turn or so once your close. Keep working them while tightening a little at a time. This is seating the rings, balls, washers and gear and lining everything up at the same time for best results in the final setting.

Too much grease will not make the diff last longer and not enough will shorten it's life span. The ball cavity in the diff gear should be full of grease on both sides during assembly, grease should not be dripping out all over the work bench during tightening. Same for thrust assembly... fully cover the balls, that is enough.

The direction of the diff bolt only matters for access to adjust it later. Direction will not determine if it loosens or not, the condition of the diff nut and thrust assembly determines that.
Think about it, the threads are right handed. Nut on the right would loosen when right wheel spins more, nut on the left it would loosen when left wheel spins more.
Only the condition of the nut and thrust matters here and access to the bolt to your preference.


Hope this helps.
Jim
__________________
www.wedjim.com ...Reopening soon. I'm still painting, just not with 40+ bodies waiting. :)
www.prolineracing.com
www.HarleyDavidson.com
"Nothing but the best!"
W.E.D.Jim is offline   Reply With Quote
Old 09-26-2013, 11:32 AM   #315
Tech Rookie
 
Join Date: Apr 2013
Posts: 16
Default

Quote:
Originally Posted by rc32 View Post
Good idea
yeah !! i agree !!
tolysk8 is offline   Reply With Quote
Reply



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 08:19 AM.


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