R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 02-08-2009, 12:12 AM   #1
Tech Adept
 
Join Date: Nov 2008
Location: Socal
Posts: 157
Trader Rating: 7 (100%+)
Send a message via AIM to sszzxx
Default Differential question

I have 2 cars now a B4 and T4 that both have the same problem if its even a problem. But i see other peoples cars and when they spin 1 wheel forward the other wheel moves smoothly backwards but on both my B4 and T4 if i spin 1 wheel forward sometimes the other wheel will spin forward or randomly "catch" and start spinning backwards like it should. Is this even a problem and how do you fix it ?
__________________
B4
T4
sszzxx is offline   Reply With Quote
Old 02-08-2009, 12:18 AM   #2
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,927
Trader Rating: 77 (100%+)
Default

#1 if you're running brushless, you won't have as much motor resistance to insure the diff will spin.

#2 That said, take your diffs apart, clean them sterile, flip your diff rings (or sand them with really fine sandpaper, like 600+ grit) and re-assemble with fresh lubes.

That should fix the problem.
Davidka is offline   Reply With Quote
Old 02-08-2009, 01:16 AM   #3
Tech Adept
 
Join Date: Nov 2008
Location: Socal
Posts: 157
Trader Rating: 7 (100%+)
Send a message via AIM to sszzxx
Default

Yes I am running brushless and ive taken them apart and cleaned them and relubed and reassembled it still does it.
__________________
B4
T4
sszzxx is offline   Reply With Quote
Old 02-08-2009, 07:05 AM   #4
Tech Initiate
 
nsane's Avatar
 
Join Date: Jun 2006
Location: Charlotte, NC
Posts: 32
Trader Rating: 1 (100%+)
Default

Part of it is going to depend on how tight your diff is.. if you've got it relatively wrenched down its going to want to spin the motor before it actuates the diff itself. If you hold the spur, is it the same way?

Does it feel 'crunchy' at all? Its possible you've flat spotted the balls in the diff, which will cause what you're seeing - the flat spot basically causes a bind.

I've been using the BFast diff rebuild kits in my Losi for a while now and I've been quite happy with their performance (much smoother) so you may want to give them a shot as well. Just make sure you break it in properly.
__________________
Tekno e-D8 (build in progress)
Kyosho Lazer ZX5 SP
XXX-T CR

http://www.ncchampseries.com
nsane is offline   Reply With Quote
Old 02-08-2009, 07:33 AM   #5
Tech Lord
 
UN4RACING's Avatar
 
Join Date: Oct 2006
Location: MODIFIED!
Posts: 13,140
Trader Rating: 22 (100%+)
Default

Could be to tight. Hold the spur gear and test it compared to the local pro. I can very carefully turn mine against the motor resistance with a brushless but if I turn it to abrupt it will turn the rotor. If your diff balls are out of round it can cause a problem or if the rings are worn. If you have to clean and rebuild I like to flip the rings and start the process just like a new diff built as well. You will get a couple more weeks or better out of your diff.

That all said I run mod and generally will run my diff a bit looser than the manual says not much, I back it off maybe a 1/16th of a turn more and adjust my slipper accordingly. I hold both wheels and floor it when the front wheels are about a 1/2'' of the ground I'm set. Of course this method can very.

Good luck on the diff its one of the most important tuning components on the truck.
UN4RACING is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
1/10th pan car Taz_S Oval, Larger Scales and More 16138 09-25-2014 10:03 AM
Xray T2'007 Joep Electric On-Road 4185 07-07-2014 09:22 AM
Any Question?? Leave your message here! rcmart rcMart.com Mega Online R/C Marketplace 819 04-20-2008 12:37 AM



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 11:31 PM.


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