R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 04-19-2004, 07:34 AM   #1
Tech Rookie
 
Join Date: Jan 2004
Posts: 18
Default Toasted XXXT diff. ring/gear

Quick question since I think I could have prevented this with the correct adjustment. I let the neighbor's kid take my newly built MF out in the field next door....As you can see from the title, after about two packs thru the truck it suddenly quit moving. I checked the pinion (fine) and proceded to tear down the tranny.

I expected to find a stripped tranny gear since he was hitting a bunch of jumps and landing them full throttle, but instead the center of the diff gear (where the diff balls snap in) was just melted away.

I had just finished building the truck and had tightened the diff appropriately I thought....


Here's the question...was the diff too tight or too loose? I assume it broke in a little with the first pack and problably got too loose causing the meltdown. Does this sound right?

It this a common problem and how can I prevent it?

Thanks,

tony
revnine is offline   Reply With Quote
Old 04-19-2004, 08:51 AM   #2
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

revnine - You guessed exactly right..the diff slipped and that's what causes the gear to melt like that.

Here's some info to help you next time!

To break in the diff:

1) Hold the truck up off the ground or table by the motorplate, with all four wheels off the surface
2) Put one rear tire on the surface, and apply a little bit of throttle and let it spin the lifted tire for about 10 seconds
3) Repeat for the opposite side, and then over again, about 5 times.

To check the diff while it's in the truck:

1) Tighten the slipper all the way down
2) Hold the right rear tire and the spur gear with your right hand
3) Try to turn the left tire...it shouldn't move!

If you have the diff out of the car, you can use two allen wrenches placed through the slots in the outdrives to hold them still and try to turn the gear for the same test.

The diff will need to be re-adjusted after break in. To check your slipper, adjust your slipper where you like it, and then perform the same test again. The nut and spring will turn if done correctly.
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 04-19-2004, 09:12 AM   #3
Tech Rookie
 
Join Date: Jan 2004
Posts: 18
Default Thanks Aaron!

Thanks for the info!

I'll be more careful next time.....live and learn
revnine is offline   Reply With Quote
Old 04-19-2004, 03:55 PM   #4
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

It's a very common mistake..don't feel bad

Let me know if you have any other questions.
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 04-19-2004, 09:21 PM   #5
Tech Regular
 
speedydave's Avatar
 
Join Date: Aug 2001
Posts: 377
Send a message via AIM to speedydave Send a message via Yahoo to speedydave
Default

Also, check to make sure you have the diff in the right way. If you have it in backward, it will loosen itself as you run, and consequently cause it to melt.
speedydave is offline   Reply With Quote
Old 04-19-2004, 09:34 PM   #6
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

That's a complete myth. Losi's instructions for the XXX-T and the XXX-NT show the diff two different ways.

The only way for the diff to loosen up would be if the nut was worn out, or if something was holding the screw into place.
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 04-19-2004, 09:36 PM   #7
Tech Regular
 
speedydave's Avatar
 
Join Date: Aug 2001
Posts: 377
Send a message via AIM to speedydave Send a message via Yahoo to speedydave
Default

I've seen it happen...maybe not with Losi's, but I've definitely seen it happen.
speedydave is offline   Reply With Quote
Old 04-19-2004, 09:41 PM   #8
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

It simply can't happen unless something is wrong.

If you have a bolt threaded onto a screw in your hand, and you turn the nut, the screw is going to turn also, unless something is holding the screw.

Unless, of course, the nut is worn out.
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 04-19-2004, 10:00 PM   #9
Tech Regular
 
speedydave's Avatar
 
Join Date: Aug 2001
Posts: 377
Send a message via AIM to speedydave Send a message via Yahoo to speedydave
Default

Hey, don't get all technical on me, Aaron! All I said was that I've seen it happen!
speedydave is offline   Reply With Quote
Old 04-19-2004, 10:27 PM   #10
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

Hahaha
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
TC3 Ring and Pinion Gear Color Centerline Racing Electric On-Road 3 01-10-2007 09:35 PM
Tamiya TNX Ring gear bag AUSTNX Australia Wanted to Buy 0 02-03-2006 06:29 PM
one Front diff - looking for Ring Gear - TC4 bvoltz Rookie Zone 1 07-17-2005 11:33 PM
IRS D-Ring diff disaster999 Electric On-Road 0 01-19-2004 11:21 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 02:25 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net