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Df03 Rear Diff Problems

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Having problems with the rear diff in a Keen Hawk. The car wasn't going well, on investigation all the drive was lost at the rear. The diff had come loose. When I stripped it on one side the flat plate that goes against the bearings had slipped on the drive piece. It put this right and rebuilt the diff. I then noticed that as I turned the drive cup on the bolt side that the bolt undid. I have replaced the nylock nut thinking this ma be at fault. I also bought some HD drive bits from Stella. By drive bits I mean the parts the bolt goes through and has the drive cups on the outer end. It is still doing this. Either I really do the bolt up tight and have a locked diff or the bolt undoes and loose drive. Any Ideas?

I read alot that the ball diff is easy to break with a hotter motor in the car. I have a slipper clutch on back order. When people say it is easy to break, exactly what breaks? Could this be what I have done?

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They do have a problem with the plastic diff outdrives. The usual fix is to buy a pair of the metal outdrives used for the front diff and use those instead.

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I stripped the two large plastic parts of the diff (with the outdrives on) with a hot motor. HD metal ones are available which are much stronger.

however, if your nut is undoing, it could be the nylon in the lock nut has worn away. It could even be that the diff got hot while it was slipping and melted the nylon. A new locking nut would be a good place to start. Also check that the spring is included - otherwise you would have to virtually lock the diff to stop it slipping.

I have found that Tamiya ball diffs need to be done up pretty tight to stop them from slipping, although this might be my lack of experience with them. The diff may feel way too tight (even locked) when turning the axles, but once the wheels are fitted it'll feel way too loose.

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My first thought was the nylock nut, so I replaced that and bought some HD metal out shafts. The diff used to be nice and free but without slipping. Could the spring be compressed? when I built the diff from new it was hard to get the bolt to thread in the nut, I had to push against the spring. It threads really easy now. Also the bearing that the bolt head presses up against if a really tight fit in the out put shaft. It could be that this is stopping the halves of the bearing turning seprately, this would undo the bolt. What do you think.

I have ordered a slipper clutch and a one way set for the front. Then I can use the front diff to rebuild the rear

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seems strange as i have had no probs with my dark impact at all the diffs bedded in very nicely front and rear no issuses with plastic outdrives and i run a checkpoint 12x2 , only upgrades i had made which i did before a wheel was ever turned waas to put a centre one way in and a slipper clutch,

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I have experienced the same problem and replaced with the metal ones. But what is crucial is that you thighten the first time very very secure. Because if you have got to retighten the diff it will end in worn out nuts and even the smal ballbearing will break.

Best to never use the plastic cups and start with the after market ones.

Max

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