R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 12-30-2008, 07:49 AM   #1
Tech Regular
 
bjr48's Avatar
 
Join Date: Apr 2008
Posts: 274
Default Universal joint rebuild?

Were these ever meant to be rebuilt? They sure don't last very long!

http://www.amainhobbies.com/product_...ducts_id/14934

Mine have all of the slop around the pins on the outside where you can see the pins if that makes sense. THe center block where the small pin goes through the large pin is still tight and the only thing that holds it together still. I can see reaming out all of the holes including the one in the center block that holds it all together and using pins that are bigger but you can't really do that more than once.
Mine were not new to me. Why do the holes go out of round and wear if they are pressed in tight from the factory? How tight are they new?
Wanted to know if I am missing something that's not obvious to me...
bjr48 is offline   Reply With Quote
Old 12-30-2008, 08:39 AM   #2
Tech Regular
 
rced1's Avatar
 
Join Date: Jan 2005
Location: Illinois
Posts: 336
Trader Rating: 17 (100%+)
Default

Hudy and Innovative Designs both make tools to replace drive pins.
Of course, the pins should be replaced before the uni holes are worn out.

The uni's wear from constant acceleration and braking. The pin - hole tolerance is very tight new. If you try to replace a pin without the tool you will see just how tight the tolerance is.
rced1 is offline   Reply With Quote
Old 12-30-2008, 08:49 AM   #3
Tech Regular
 
bjr48's Avatar
 
Join Date: Apr 2008
Posts: 274
Default

I'm familiar with replacing the pins on the dogbone ends and have done that on all of the shafts on my buggy with only dogbones. Those, the pins wear flat spots against the drive cups.
My front uses uni's on the steering knuckles and seemed to wear different. The pin still looks round but the outer holes they go in are ovaled real bad. If I press the pins out I don't expect to see any wear on the pin from what I can see at the end of the pin. Maybe I will have to go ahead and take one out to verify. I wish the pins wore first then the other pieces. At this point it seems like the other way around - unless that is the point you are trying to make. That I will find the pins and the holes are both worn and I've neglected them. Don't have experience with these

If this is true I could overhaul them and put bigger pins in some reamed out fresh holes that are round again and keep a better eye on them. Not sure what happened yet and looking for some more advice before I screw them up...
bjr48 is offline   Reply With Quote
Old 12-30-2008, 09:31 AM   #4
Tech Regular
 
bjr48's Avatar
 
Join Date: Apr 2008
Posts: 274
Default

I just caught on to one important thing I missed while staring at these things. The pin cannot be a press fit at the ends of the pin or the uni's won't pivot at all. D'oh.
Maybe these aren't as worn as I thought. They still are pretty worn though. I'll have to rethink how I could make them better. It makes more sense how they wear so bad and quick now
Give me any ideas so I don't have to put them back in so sloppy. The only problem with leaving them is that they will get worse and eventually break. The way I see the design now there is no way that they could really wear any slower. There has to be a tight but moveable fit for them to pivot.
Makes the plain old dogbones look like lower maintenance!
bjr48 is offline   Reply With Quote
Old 12-30-2008, 09:40 AM   #5
Tech Fanatic
 
Tree's Avatar
 
Join Date: May 2006
Location: Murrieta, California
Posts: 839
Trader Rating: 8 (100%+)
Send a message via ICQ to Tree
Default

I am running Kyosho unis on my Cen Matrix buggy. Mine also show signs of wear and they are developing some slop. I was told that Kyosho unis and CVDs cannot be rebuilt. I know that the Mugen Unis and CVDs are rebuildable.
__________________
Team Holy Rollers
HiTec Servos
"N-Tune" Nitro Engine Tuning Dials
Tree is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
RC BLOW OUT SALE!! Great Prices and several lots Frank Root R/C Items: For Sale/Trade 17 12-08-2008 10:34 AM
Hotbodies Cyclone - HPI Pro4 - Spare Parts domo Australia For Sale/Trade 12 08-19-2007 06:52 PM
2-Xray T1FK05 roller with tons of spares Bmi T1fk GMartinez R/C Items: For Sale/Trade 43 12-06-2005 12:59 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 12:18 AM.


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