R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 01-11-2009, 12:35 AM   #1
Tech Elite
 
dishsoap's Avatar
R/C Tech Elite Subscriber
 
Join Date: Jan 2009
Location: Tucson, AZ
Posts: 2,457
Trader Rating: 7 (100%+)
Default Rear Drive Shaft To Middle Outdrive Fit?????

Ok so some of you know that I had to service my diffs for the first time. It was a success.

My question is about the fitting from the rear drive shaft to the middle outdrive on the middle diff.

I didnt pay attention to har far inset the the drive shaft was to the middle outdrive before pulling the rear apart. After I got everything back toghether I notice that drive shaft was fitting flush in the outdrive. None of the other drive shafts fit like this one as the cross bars on the ball joint sits in the middle of the outdrive.

I tried to loosen up the middle diff from the bottom chasis to see if i could get a better fit however I had no luck.

The cross bars are sitting flush in the outdrive and it is secure its just not sitting as deep as the rest are. I spun the wheels and the rear drive shaft is engaged and everything seems to be turnning normal.

Is this normal or should I try to get a better fit before running it?

Thanks everyone.
__________________
HobbyTown USA Tucson!!! HobbyTown USA SRS!!!!
dishsoap is offline   Reply With Quote
Old 01-11-2009, 01:41 AM   #2
Tech Regular
 
Gliptal's Avatar
 
Join Date: May 2007
Location: Portland, OR
Posts: 258
Default

8ight? If so then that is correct, there isn't much of an angle on the rear center drive and i think the extra room is for chassis flex.
Gliptal is offline   Reply With Quote
Old 01-11-2009, 01:59 AM   #3
Tech Adept
 
Join Date: Sep 2008
Posts: 215
Default

I am not sure about your particular car but try checking out how far the front center driveshaft is sticking into its outdrive. If its quite a bit deeper, or deeper at all, swap them around and check their fits.
Also make sure you didnt accidently put the center diff carriers in the wrong spot, on my make of car there is a specific front and rear carrier. Ideally, the pins should be centered in the outdrive so there is max travel in and out of the outdrive. The Losi 1/8 scales use CVDs or something similar right???? If so, you shouldnt have to seperate the center driveshafts from the pinion gears to service the center diff. Usually you remove the brake/throttle linkage, unfasten the diff carrier from the chassis and lift it straight up.
Another thing, if you disassembled your F or R pinion assemblies make absolutly sure everything is assembled how its supposed to be, refer to a manual if you have it. If your pinion gear axial endplay (front to rear play in relation to the car) is too loose, then the pinion can slide too far into the bulkhead making the driveshaft appear it is too short. This can also cause some serious damage to the ring/pinion gears and pinion bearings. Especially with the way that Losi flexes.
Good Luck!!!!
__________________
Ive done everything Hank did but die
NCWC is offline   Reply With Quote
Old 01-11-2009, 04:03 AM   #4
Tech Addict
 
Join Date: Oct 2008
Posts: 577
Default

On my rc8 you have to push the pinion from the inside of the case and then put the center driveshaft on the input making sure it is all the way on before tightening the set screw. If you can not push the pinion from the inside with your finger it will have the effect of the driveshaft appearing to be too long.You have to do this before you put the diff in the hole!I am not sure what model you have but I think this would probably be the same?
Joey Platinum is offline   Reply With Quote
Old 01-11-2009, 05:20 AM   #5
Tech Elite
 
Zerodefect's Avatar
 
Join Date: Apr 2008
Location: Underground, Ohio
Posts: 4,304
Default

Quote:
Originally Posted by Joey Platinum View Post
On my rc8 you have to push the pinion from the inside of the case and then put the center driveshaft on the input making sure it is all the way on before tightening the set screw. If you can not push the pinion from the inside with your finger it will have the effect of the driveshaft appearing to be too long.You have to do this before you put the diff in the hole!I am not sure what model you have but I think this would probably be the same?
I think he's saying his problem is the the shaft is too short. Barely in the drive cup. I hate it when my dogbones shrink!

Sounds weird, can any other eight guys chime in? I think if you accidentally installed the shafts on the wrong side they wouldn't fit at all. Is one shaft dramaticly longer than the other? Are both center diff outdrives the same?
Zerodefect is offline   Reply With Quote
Old 01-11-2009, 07:36 AM   #6
Tech Master
 
jrwoodchuck's Avatar
 
Join Date: Nov 2007
Location: Northampton, Massachusettes
Posts: 1,336
Default

both my eights were like this. ran fine until i would case a jump and the rear shaft would pop out. i fixed it by loosining up the set screw in the rear coupling ware it connects to the pinion shaft. their is a flat spot on the pinion shaft that is about 3/16 of an inch, this will allow for adjustment. so lossen up the set screw and pull the coupling forward as far as it can go "without" getting off that flat spot and tighten it back down. then it will be ok. but now you will have a gap between the coupling and the pinion shaft bearing. i wish i new what i used as a spacer, but i can't. i have a bunch of plastic spacers from years of racing laying around. and i now run xray so i can't even look to tell you what i might have used. but make sure you use something as a spacer so the bearing won't work it's way out of the diff case. hope this helps
__________________
Doug
TLR 22/M-11

“Looks like I picked the wrong week to quit sniffing glue.”

Last edited by jrwoodchuck; 01-11-2009 at 08:00 AM.
jrwoodchuck is offline   Reply With Quote
Old 01-11-2009, 10:33 AM   #7
Tech Elite
 
dishsoap's Avatar
R/C Tech Elite Subscriber
 
Join Date: Jan 2009
Location: Tucson, AZ
Posts: 2,457
Trader Rating: 7 (100%+)
Default

Sorry I should have mentioned my buggy it was late. Yes it is a Losi 8 buggy. I know I put everything back that way it was suposed to go. I only serviced one diff at one time. It took me 5 hours thats how slow I went.
__________________
HobbyTown USA Tucson!!! HobbyTown USA SRS!!!!
dishsoap is offline   Reply With Quote
Old 01-11-2009, 12:42 PM   #8
Tech Elite
 
dishsoap's Avatar
R/C Tech Elite Subscriber
 
Join Date: Jan 2009
Location: Tucson, AZ
Posts: 2,457
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by Gliptal View Post
8ight? If so then that is correct, there isn't much of an angle on the rear center drive and i think the extra room is for chassis flex.

Called the local hobby shop no help as usual. They just said "Well if it makes a weird noise then somehting is wrong" I am going to run it and see how it does.

On the current set up I am wondering if balancing will be a problems as the front dogbone is set deeper on the outdrive and the rear dogbone is more flush. I am wondering this because both front and rear work off of the same middle drive. If anything the rear setting may cause more wear and tear and could possbily be more stressed while spinning.

I am pissed I should have looked before I pulled it apart and then I wouldnt have to worry.

If any current losi 8 buggy owners have some time can you take a quick look at yours to see if this is how its set up.
__________________
HobbyTown USA Tucson!!! HobbyTown USA SRS!!!!
dishsoap is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tamiya DF-03 type tom_chang79 Electric Off-Road 1048 01-17-2016 09:06 PM
First Time racing/driving the JRX-S... rustlerboi1052 Electric On-Road 36 09-10-2007 01:17 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 01:59 AM.


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