Ofna Cd-3

Old 08-20-2006, 08:34 AM
  #1111  
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3 words can pretty sum up the last points series race: 'catastrophic drivetrain failure'. During the 3rd qualifier, the car had absolutely no acceleration coming off the back straight. I had to baby it to the pits and pull it off the track. From the sound, I figures I stripped a spur gear. Little did I know...

It appears that one of the bearings on the rear bevel gear siezed up, frying the gear and melting the diff case along with it. Not the end of the world; I had another old cear and a diff case. I made the swap in 20 minutes (btw, the c/f shock tower makes this more of a pain than it needs to be). Everything seemed to spin fine in the back, but the front didn't move. Not a good sign. Opened that diff case expecting that the one way bearings were shot. Even worse: all 4 screws had sheared off, leaving the bevel gear to spin free. Really not good. I managed to get 2 of the broken screws out, but I haven't got the others out yet. Fortunately I had that other diff built. I putthat in, dialed in some more brake, and ran it for all it was worth. Needless to say I have some parts to buy
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Old 08-20-2006, 12:19 PM
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Ouch.

Had my first turnbuckle failure today. Mind you this turnbuckle is the original one from LD3 days so its had plenty of action.

Coming out of the sweeper onto the straight and made an error in judgement (too much throttle) and bang into the boards. To my surprise snapped the rear top arm turnbuckle.

At least I seen more action with the CD3 then with the Tamiya Evo III Qualified 2nd only to go bang straight into the boards 1st corner of final start. stripped spur gear - my fault for dodgy mesh. Controlled rubber tyre & no tyre wamers = ouch heheh (warmers on the way)
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Old 08-22-2006, 07:54 PM
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Icky. All the parts should be in Friday. I ordered some servos too as a backup. That, and one of mine went up in smoke (no comments from you nightmare!). I'm going to try to get those other 2 screws out of the one way. If I can't, I'll just run with 2 for the time being (they are on opposed sides, so it should stay somewhat true). I friend of mine just got a Pro RTR, so I have to show him what's what. Maybe I'll give him that OS I still have. It's got to have more power than that Force.

BTW, I haven't forgot the pictures. I just haven't figured out the best way to post them!
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Old 08-22-2006, 11:56 PM
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spenzalii,
what screws are you using for the diffs? the ones I have are stainless (As much as I dont like stainless) but I guess its better then no spec steel.

I wanted to get some high tensile ones at first but the 304 stainless have been fine so far.
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Old 08-23-2006, 10:30 AM
  #1115  
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Hi guys,

new here, just got my CD3 about a month ago, im loving it! i got the car 2nd hand but its in great condition, except for the tweaked chassis
no prob though i ordered my new one and it will be here tomorrow.
You can have a look at some pics here http://www.putfile.com/delta9b

I have a question about the diff, my rear diff seams a bit stiff compared to my other offroad nitro's, if i spin the rear wheels forward the other also turns forward, but if i spin it backwards the other one spins forward,is this correct? im not sure how to explain it but it just doesnt feel like my other diffs, i have stripped the rear diff and there is very little grease in the diff, im going to the LHS 2moro and just wanted some suggestions as to what diff oil to get for the rear, it has a one way in the front.
Im just going to be bashing in a parking lot for the next month or so till i can control the car enough to go to the track ( lol its totally different to my offroad cars )
any tips and suggestions are most welcome.
TIA
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Old 08-23-2006, 11:16 AM
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Default floating body

hey i heard the cd3 has a floating body ????
whats it mean and do . i dont know if mine
has it . can anyone help.???? an how do i know if i got it
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Old 08-23-2006, 11:18 AM
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Serpent rush, if you look at the link to my pics in the post above urs, look at the rear body posts, those ar the floating body mounts u asking about
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Old 08-23-2006, 12:28 PM
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OK thanks i have the cd3pro with no hop ups .
or i missed something in the box
i dont recall body mounts like that . by the
way where in sa are you
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Old 08-23-2006, 12:33 PM
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Delta9,
Depends on your traction levels. some people run 100k diff oil in rear, I am currently running 50k oil & grease mixture (in the CD3 Pro 6 gear diff, RTR diff has 4 gears so the oil has less effect on it).

If its a Pro it should of been silicone diff oil but maybe it is grease, depends who built it

If you are having problems loosing the rear end as you 1st apply power when coming out of corners the rear diff oil could be too thick, thats why I dropped from 100k to 50k & grease mix.

serpentrush,
A number tried the floating rears but I think most people (including myself) went back to standard as it made the rear end have too much grip (not enough up front = loss of steering)
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Old 08-23-2006, 02:39 PM
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Thanks au_Nightmare, I will give the 50k a try, i think i have the 4 gear diff, its is the Pro kit, but its the Hong Nor version so im not 100% sure, it looked like a 4 gear diff to me. It definately looks like automotive grease in there at the moment.
Thanks for the tip, will try it this weekend, and let you guys know how it goes.
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Old 08-23-2006, 02:40 PM
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Originally Posted by serpentrush
OK thanks i have the cd3pro with no hop ups .
or i missed something in the box
i dont recall body mounts like that . by the
way where in sa are you
Im in Joburg, you from here?
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Old 08-23-2006, 08:01 PM
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Originally Posted by Delta9
Thanks au_Nightmare, I will give the 50k a try, i think i have the 4 gear diff, its is the Pro kit, but its the Hong Nor version so im not 100% sure, it looked like a 4 gear diff to me. It definately looks like automotive grease in there at the moment.
Thanks for the tip, will try it this weekend, and let you guys know how it goes.
Pretty sure the Pro has the 6 gear diff. Looks nice. I have the 100k in my rear, but the track I run at has tons-o-grip. Careful with those shock towers when you start racing.

nightmare
I think I used the stock screws that were in the kit. I ordered the stainless screw swt, but they only had a caphead 2mm screw, which wouldn't let the bearing set on the one way. I got 3 out of 4 screws out and put some new ones in. If I can find a stainless or aluminum set I'll pick them up.
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Old 08-23-2006, 11:56 PM
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Thanks Spenzalii, maybe i will pick up a bottle of both oils to try. How full should i make the diff? about half way?
I worry about those shock towers while im just bashing LOL
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Old 08-24-2006, 12:01 AM
  #1124  
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Spenzalii,
Maybe you can find a screw shop close?

http://www.mcmaster.com/
M2 x 8mm
Steel: Part # 91294A005 (Minimum tensile strength is 145,000 psi)
316 Stainless: Part # 93395A141 (Minimum tensile strength is 101,000 psi)

The ones I have are 304 stainless (95,000 psi ? I think).

Go the seel, stonger, cheaper and you get over 2.5x more screws

Delta9 - if the diffs to "thick" causing rear traction problems you can always mix more auto grease with it. Don't expect it to feel like a ball diff though. For best performance you want it as thick as you can without causing rear traction problems.
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Old 08-24-2006, 12:05 AM
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oh yeah, FYI my last diff I built I managed to get two shims in behind the gears that connect to the drive cups - diff was smoother...
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