jamescottam 0 Posted August 22, 2016 I'm wondering if someone can help me here. I purchased a pair of Blackfoot 2016s and am totally stumped by a significant drive-line issue. I have gone over the assembly a number of times and I cannot understand why the right side (motor side) CV easily pops out of the cup. I can easily pull it out with my hand when the entire unit is assembled. It's almost as if the joint are a few millimeters too short. Have I assembled it wrong? Is this a flaw in the design? I ran it all of one minute and, sure enough, the CV pops out of the cup. I'm almost regretting I bought 2 of these! I have attached a couple of pics. Here's hoping someone has a fix or suggestions. It seems odd that Tamiya would release this truck with such an obvious flaw, given the Monster Beetle's release last year. Share this post Link to post Share on other sites
Nobbi1977 1793 Posted August 22, 2016 Is the shock fitted? Do they limit travel if not to stop the dog bones popping out? do these have an o ring in the outer cup to space it out a bit? Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 5 minutes ago, Nobbi1977 said: do these have an o ring in the outer cup to space it out a bit? I've noticed in the MB Re-Re manual that the right-side CVD needs (2) o-rings in the drive cup... Frankly, isn't the recommended Hop-Up for this issue to go with these: Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 Thanks for the reply. Yes, the shock is fitted. There are no o-rings in the outer cup, but it's not really a cup - it's a CV joint. Share this post Link to post Share on other sites
Nobbi1977 1793 Posted August 22, 2016 I had no idea these came with universals as standard, pity they are to short. I am sure others who have built these will be along with ideas soon. Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 Thanks for your time. I can't believe I am the only one dealing with this issue. We'll see... Share this post Link to post Share on other sites
Nobbi1977 1793 Posted August 22, 2016 The kit is the same base as the Re-re monster beetle. Loads of issues with that if you search for them here. Maybe this is one of the known faults? At least the short drive shafts have stopped you running it and striping the gearbox teeth. Share this post Link to post Share on other sites
gt6++ 29 Posted August 22, 2016 Silly question but, have you put the ball bearing on the inside of the rear axle hub? Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 2 minutes ago, Nobbi1977 said: The kit is the same base as the Re-re monster beetle. Loads of issues with that if you search for them here. Maybe this is one of the known faults? Grab yourself a 6er, send the kids and wife to the in-laws, and get ready for a long night of reading... Somewhere in there is the fix for this known issue... Terry Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 Yes, I have ball bearings inside the axle hubs. I am quite stunned Tamiya would release a kit like this with such obvious and known flaws. Makes me wonder.... Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 Looks like the fix is to get Tamiya 9808038 (pair of dogbones) and Tamiya 9808039 (pair of rear axles)... Terry Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 You may be right. To be honest I find that crazy! Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 3 minutes ago, jamescottam said: You may be right. To be honest I find that crazy! What it comes down to is this: Tamiya got the same box for the MB and the BF, they only changed the box top. That means the flaws in the first survive into the second... Make economic sense if you're Tamiya. Its crazy if your one of us... Yeah, I'm a bit disappointed. I grew up knowing the Tamiya paid attention to the details, ie their models were always so much better than the Monograms and Revells... Good luck! Terry Share this post Link to post Share on other sites
gt6++ 29 Posted August 22, 2016 There must be an explanation. The flaw is too blatant. I don't understand how one side is ok and the other not, both CV are the same length? It is not the same old attention to quality of yesteryear'sTamiya !! Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 1 hour ago, Nobbi1977 said: The kit is the same base as the Re-re monster beetle. Loads of issues with that if you search for them here. Maybe this is one of the known faults? At least the short drive shafts have stopped you running it and striping the gearbox teeth. At this rate all it will be is a shelf knick knack. Share this post Link to post Share on other sites
jamescottam 0 Posted August 22, 2016 1 hour ago, Frog Jumper said: Grab yourself a 6er, send the kids and wife to the in-laws, and get ready for a long night of reading... Somewhere in there is the fix for this known issue... Terry Thanks! i'm looking. Much of the talk seems to be that the arms are too long and thus bind when the suspension is compressed. I can't keep the CV joint in the cup long enough for that too happen. Share this post Link to post Share on other sites
Hobbimaster 190 Posted August 22, 2016 My Tamiya MB had gear box issues using the supplied CV axles. The axle never actually popped out but the gear diff was toast after 2 runs. It had more to do with the angle of the joint itself, or should I say lack of angle that put stress on the out-drive. Ultimately, I just used the Frog shafts and cups, spaced the dog bone using black o-rings per Frog and it has been perfect since. Shame Tamiya didn't address this with the Blackfoot. Looks like I'm going to hold on purchasing one now. Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 24 minutes ago, jamescottam said: Thanks! i'm looking. Much of the talk seems to be that the arms are too long and thus bind when the suspension is compressed. I can't keep the CV joint in the cup long enough for that too happen. Yeah, I'm not going to be able to help much beyond pointing you to the MB thread... I upgraded my old Frog with Thorp and Robinson parts before the MB re-re came out, so my solution was a bit more pricey, but is rock-solid... Terry Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 28 minutes ago, jamescottam said: At this rate all it will be is a shelf knick knack. Don't give up on her! IMO, go with the dog-bones and see if that fixes it. Also get a set of MHeald's side plates. That should take care of any rear-end problems, at least so you can enjoy the car rather then letting it collect dust... Also, go ahead and get a second body. That way you can destroy one and still have the nice one at home to look at... Terry Share this post Link to post Share on other sites
jupitertwo 1484 Posted August 22, 2016 I've had this issue a lot, one dog bone popping out regularly. I couldn't work it out, and didn't have much luck with that thread. It gradually got more frequent, until this evening any bump seemed to knock it out. Closer examination showed me that the right shock arm seemed to be flexing. That lead to me seeing that the mount for that was loose, allowing too much movement on that side, allowing the dog bone to pop. I've not got my own photo of the part I mean, but the black 'p' shaped section in this image is the one I adjusted: Might not not cure your issue, but worth a check to see if it's loose Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 9 minutes ago, jupitertwo said: I've had this issue a lot, one dog bone popping out regularly. I couldn't work it out, and didn't have much luck with that thread. It gradually got more frequent, until this evening any bump seemed to knock it out. Closer examination showed me that the right shock arm seemed to be flexing. That lead to me seeing that the mount for that was loose, allowing too much movement on that side, allowing the dog bone to pop. I've not got my own photo of the part I mean, but the black 'p' shaped section in this image is the one I adjusted: Might not not cure your issue, but worth a check to see if it's loose Yeah one of the lesser known issues is the swing arm flexing, especially during turns... Another issue is the 'p' shaped brackets not holding the arms solidly, allowing play... To alleviate the 'p' bracket issue, you can get a CRP 1606. This piece allows you to run a length of threaded rod under the chassis, through the second battery door hole, and you can loosen or tighten as needed. There is also a variety of kits (DIY and otherwise) that tried to solve the flex issue, like threaded rods with ball-end, wire kits, etc... Terry Share this post Link to post Share on other sites
Pumesta 407 Posted August 22, 2016 I had this problem when I restored my original Blackfoot messed about with the 'P' bracket and swing arm and I don't know what I done but it fixed the problem. When restoring my Monster Beetle I had the same problem made worse when I fitted the sport tuned motor, I never managed to fix it. In the end I dumped the UJ's and fitted normal dog bones Share this post Link to post Share on other sites
Frog Jumper 3605 Posted August 22, 2016 https://www.pinterest.com/pin/436919601328740183/ This Hot Trick Frog Prince has a wire supporting each swing arm (aluminum .50caliber arms it looks like)... The wire is supposed to help with spread... Terry Share this post Link to post Share on other sites
jamescottam 0 Posted August 23, 2016 Well I ordered some frog dog bones and cups off eBay last night. Parts like that are tricky to find where I live. Fifty bucks just to get the thing to run properly out of the box!! 16 hours ago, Frog Jumper said: Don't give up on her! IMO, go with the dog-bones and see if that fixes it. Also get a set of MHeald's side plates. That should take care of any rear-end problems, at least so you can enjoy the car rather then letting it collect dust... Also, go ahead and get a second body. That way you can destroy one and still have the nice one at home to look at... Terry Where do you get those side plates? eBay? J. Share this post Link to post Share on other sites
73robb 132 Posted August 23, 2016 See below, if you PM mheald he should be able to sort you out. Share this post Link to post Share on other sites