mrbiccies 6 Posted October 15, 2016 Folks, What is the solution to sort out the rear diff, I rebuilt the diff following the manual VERY carefully and within 5 mins of running it has melted. Is there an alternative after market metal diff? I think there was a few years ago but can't find it now..... Cheers Share this post Link to post Share on other sites
mrbiccies 6 Posted October 15, 2016 Is it worth finding a way to lock the diff? I'm losing patience and feel like throwing it in the bin to honest! Share this post Link to post Share on other sites
TwistedxSlayer 1290 Posted October 15, 2016 Is this a ball diff? Share this post Link to post Share on other sites
Hobbimaster 190 Posted October 15, 2016 If its set too loose, even slipping a little, it will melt the drive gear. I've melted a few diff's. I've found that tightening the diff bolt all the way down till it stops, then backing it out 1/4 to 1/2 a turn helps. Also it helps to have a slipper clutch installed. It can be set to slip before the diffs do. I'd also suggest getting the metal out drives for the rear diff, the same ones used in the front diff are fine, it helps keep the diff set properly. 1 Share this post Link to post Share on other sites
Wooders28 4723 Posted October 15, 2016 I run tungsten balls, yeah racing steel diff joints,with 5700kv on 3S and had zero issues with the diffs. Do have a slipper, but i dont know if that would effect the diff melting. 1 Share this post Link to post Share on other sites
mrbiccies 6 Posted October 15, 2016 I'll have to revisit this. I don't think it was loose to be honest though, I checked and double checked before fitting it. Share this post Link to post Share on other sites
kontemax 1725 Posted October 16, 2016 Ok, follow me. Your ball differential melts because you have a too powerful motor so it slips and generates a massive heat that melts the gear. First question: - Do you have the slippery clutch? If not, mount one of these because is mandatory on DF03 with a powerful motor. If you have it, the clutch is too tight and need to be more loose. Second question: - Is your rear ball differential original or modified? If it is original you need another Hop Up: http://www.rcmart.com/3racing-df0303v2hd-rear-diff-shaft-heavy-duty-df03-p-30465.html If you have not, or if you can't have or buy this option, disassemble the front ball differential and take these full steel parts from there and mount the rear plastic/steel ones into the front ball differential. You should resolve your problem with these infos. If the rear ball differential continues to melt also with these modifications probably your motor is really too much powerful for your model. Max 2 Share this post Link to post Share on other sites
mrbiccies 6 Posted October 16, 2016 I have a brushless setup fitted (ezrun 9T), It does have metal outdrives and a slipper clutch fitted (53925), The slipper may be too tight, I'd need to check when I get time. I have a new unopened 3mm lightweight ball set (53379) but no new 55T differential gear. Is it a bad idea to reuse the diff plates? Share this post Link to post Share on other sites
kontemax 1725 Posted October 16, 2016 Probably you grinded the diff plates. Can you reverse them? If not buy new ones or reverse them in the opposite face. Check your clutch, it must work, if the clutch doesn't slip, the diff will slip. I used a 12x2 brushed motor on my DF03, never had a problem. Max 1 Share this post Link to post Share on other sites
mrbiccies 6 Posted October 16, 2016 Thanks for your advice. I'll make time next week to have look. Looks like I need to put together a shopping list....... Share this post Link to post Share on other sites
mrbiccies 6 Posted October 16, 2016 Is it possible to buy the diff plates seperately or do I need the complete metal gear parts bag? Edit: http://www.ebay.co.uk/itm/Tamiya-50880-TA04-Ball-Differential-Plate-Set-TRF414-TRF415-TA05-DF03-TB03-NIP-/391524509983?hash=item5b28ade91f:g:grAAAMXQySpRQl1G Share this post Link to post Share on other sites
Wooders28 4723 Posted October 16, 2016 I'm not sure at what point it becomes a weak link,some people have said they've no problems, but anyway, this is the thread i posted:- Share this post Link to post Share on other sites
Hobbimaster 190 Posted October 16, 2016 Here's a few more tips when rebuilding the diff. As stated, make sure the balls are new, and plates have no grooves. If there are grooves, either flip the plate over to get a new surface, or buy new plates. Compress the diff spring with pliers first, just a squeeze or 2 just to get the spring set and ready to go. Also I like to "run in" my diffs using a drill before making a final diff bolt adjustment. To do this I build up the diff, get it reasonably tight, and then take my battery drill and lightly stick one outdrive in the chuck of the drill. I then hold the gear and spool up the drill for about a minute. This will let the outdrives to spin opposite each other and basically breaks in all the moving parts. Then I go in for a final adjustment. You need to take 2 allen keys, or something that will allow you to lock both outdrives to keep them from spinning, basically with one hand, while trying to turn the gear with the other hand. It should be extremely hard to turn, to almost impossible. Again, as I stated earlier this tends to be about 1/4 to 1/2 a turn out from full diff bolt lock. You can start with 1/2 turn out and go from there. The slipper is fairly easy to set. Set car on table, take off gear cover, loosen slipper nut to about 1-2mm past the threaded shaft, and try to turn spur gear. This you want to feel it slip, totally opposite the diff setting. Then go test in a field. You want to hear the diff slipping for about a foot, or 1/2 meter. Its best to start with a loose slipper, and then gradually tighten it up to get the desired effect. Its there to protect the entire drive train, and helps aid in high grip situations. Share this post Link to post Share on other sites
mrbiccies 6 Posted October 29, 2016 New parts are here so I'll hopefully get this done over the next few days Share this post Link to post Share on other sites