R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 09-18-2005, 05:03 PM   #1
Tech Initiate
 
syconate's Avatar
 
Join Date: Aug 2005
Location: Bracken Ridge, Queensland
Posts: 28
Default Grinding diff

OK guys my XXXT started making a grinding noise and i assumed that it was the diff but after stripping down the diff it seemed fine, the motor is fine and both spur and pinion gears are fine. Anyone got any ideas?
syconate is offline   Reply With Quote
Old 09-18-2005, 05:55 PM   #2
Tech Master
 
Platinum_Racing's Avatar
 
Join Date: Jun 2005
Location: Rowley MA
Posts: 1,844
Send a message via MSN to Platinum_Racing
Default

Check the spur again. If the teeth are warped it could make a strange sound. The idler gear and top gear could also be what's causing the noise. Check them all for stripage and replace any if neccesary. Reset the gear mesh and try again. If it still makes the noise, try adjusting the slipper clutch, or taking it apart to see if there's any dirt or grit in there.
Platinum_Racing is offline   Reply With Quote
Old 09-18-2005, 06:07 PM   #3
Tech Adept
 
Join Date: Oct 2004
Location: Dallas, TX
Posts: 145
Default

Try to narrow it down. Turn the tires without the motor in and see you still hear the grinding. If not, put the motor in and line up the gear mesh. turn on the car and give it just a little gas to turn the tires slowly and see if you hear it then. Try it at different speeds.

If you hear without the motor in place, the problem is going to be in the diff somewhere. Completely break it down and clean everything. Inspect everything, too.

If you hear it with the motor in place, it is most likely the gear mesh. Check you spur gear and your pinion gear. Make sure the mesh isn't too tight. You want a little play.

If the spur gear looks good, check your motor plate. Take it off and hold it against a piece of glass to be sure it lines up straight. If it's off a bit it's bent and it will mess up your gear mesh. Replace the motor plate in that case. If it is the stock plate that comes on the RTR, it bends pretty easily. Get one of the anodized aluminum ones, but only if you have to replace the plate.
briansid is offline   Reply With Quote
Old 09-18-2005, 06:08 PM   #4
Tech Adept
 
Join Date: Oct 2004
Location: Dallas, TX
Posts: 145
Default

Platinum beat me to the punch.
briansid is offline   Reply With Quote
Old 09-18-2005, 06:14 PM   #5
Tech Master
 
Platinum_Racing's Avatar
 
Join Date: Jun 2005
Location: Rowley MA
Posts: 1,844
Send a message via MSN to Platinum_Racing
Default

Sorry, I'm just good like that. You did add the info about the motor plete. I don't actually have a XXX-T, but I do have a XXX-NT, and I know the diffs in that truck absolutly suck, so I wouldn't be suprised if your diff was grinding.
Platinum_Racing is offline   Reply With Quote
Old 09-18-2005, 06:30 PM   #6
Tech Master
 
JoshR 85's Avatar
 
Join Date: Aug 2003
Location: Franklin
Posts: 1,345
Default

HeY!!!

it could be the motor... just last week someone had a chipped brushed n ran it n kept sounding worse and worse as he kept driving it till i told him to check the motor and rebuild it... or last problem that i cant think of is if you have an rpm gear cover i know that sometimes the spur gear will rub on them but mainly only on the T4's.....
hope this helps out n good luck findin the problem...

LaTa
JoshR 85 is offline   Reply With Quote
Old 09-18-2005, 08:11 PM   #7
Tech Adept
 
Join Date: Oct 2004
Location: Dallas, TX
Posts: 145
Default

The gear cover is a great point. I have an RPM gear cover and I had to cut sections on the top and bottom part of the cover so the spur gear wouldn't rub. I lost a spur gear every few weeks from grinding against the cover. The RTR uses a 88 tooth spur and that causes a major problem with the RPM covers. The 86 tooth doesn't do it near as much.
briansid is offline   Reply With Quote
Old 09-18-2005, 09:37 PM   #8
Tech Elite
 
Join Date: Oct 2004
Location: Michigan
Posts: 3,319
Trader Rating: 28 (100%+)
Default

Oops, wrong thread.
jbrow1 is offline   Reply With Quote
Old 09-18-2005, 10:46 PM   #9
Tech Initiate
 
syconate's Avatar
 
Join Date: Aug 2005
Location: Bracken Ridge, Queensland
Posts: 28
Default

Thanks guys for the great info but i have gone over it twice and i am at a loss.
I rolled it back and forward without the motor in and everything felt smooth, i gave the motor a quick spin out of the truck and again it felt quite smooth, then when it was all back in i rolled the truck back and forward STILL SMOOTH!!! then i turned it on and gently gave it some throttle and not so smooth now!!!

I have replaced the spur with 86T Kevlar about 3 days ago and adjusted everything acordingly and it was running sweet.

I really am having some dramas with this thing!

Nate
syconate is offline   Reply With Quote
Old 09-19-2005, 01:28 AM   #10
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

Is it a chirping noise? Or a legitimate "my tranny sounds like rocks in a blender" grinding?

Platinum - What don't you like about the diff? It shouldn't be any different than the diff in any other car you've had..I think Losi did a great job on the diff in our gas truck. Is there anything I can help you with, or help to make it better?
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 09-19-2005, 03:30 AM   #11
Tech Initiate
 
syconate's Avatar
 
Join Date: Aug 2005
Location: Bracken Ridge, Queensland
Posts: 28
Default

Its the rocks in a blender thing!
syconate is offline   Reply With Quote
Old 09-19-2005, 06:01 AM   #12
Tech Rookie
 
Join Date: Jul 2005
Posts: 8
Default

Quote:
Originally Posted by syconate
Its the rocks in a blender thing!
I think I may have a similar problem. I have a Raptor 27 Truck and it starts first time, every time. NICE. So I start it up and rip it a while around the field. It then slows down and stops but the motor is still going. When I rev it it does'nt go, it sound like something is slipping inside. Carfully with the technical stuff because I have'nt a clue. HELP.
Thanks.
Carpy is offline   Reply With Quote
Old 09-19-2005, 02:47 PM   #13
Tech Elite
 
Join Date: Oct 2004
Location: Michigan
Posts: 3,319
Trader Rating: 28 (100%+)
Default

Carpy, sometimes if you have a roasted diff, it'll work when it's cold. And you can't really tell if it's blown if you're not experianced with the mechanical side of rc yet because everything is pretty much locked together. But when it gets warm or hot the parts unlock and just spin. You probably have to take apart your tranny and see if that's the case. Best thing is to just use the manual and tear it down.
jbrow1 is offline   Reply With Quote
Old 09-20-2005, 01:23 AM   #14
Tech Elite
 
Aaron Waldron's Avatar
 
Join Date: Apr 2004
Location: Escondido, CA
Posts: 3,720
Default

If you hold the right rear tire and the spur gear with your right hand, and turn the left rear tire with your left hand, what happens? Any noises? Can you turn it?
__________________
Aaron Waldron - LiveRC
www.liverc.com
Aaron Waldron is offline   Reply With Quote
Old 09-20-2005, 03:23 AM   #15
Tech Initiate
 
syconate's Avatar
 
Join Date: Aug 2005
Location: Bracken Ridge, Queensland
Posts: 28
Default

ok, left wheel does not move when holding right rear and spur gear.
syconate is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pinion gear grinding darkness Electric On-Road 7 02-07-2006 03:54 PM
Crank grinding, who to....... rcfoolz Onroad Nitro Engine Zone 11 11-03-2005 07:49 PM
grinding gears stevie605 Nitro On-Road 3 02-03-2005 08:12 AM
Grinding a 7 port sleeve revzalot Onroad Nitro Engine Zone 4 02-02-2005 05:54 PM
new here, but my 4-tec is grinding...? t3guy Electric On-Road 12 05-24-2004 01:01 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 08:46 PM.


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