Lazer Diff in DB1

[DJ's Dad]

I'm missing something somewhere, we've just stripped a second crown gear in a Lazer diff both lasted less than 3 minutes. I've replaced the both gears and the casing. I've checked the mesh and adjusted the shims washers accordingly.

I've built 4 Lazer front/rear diffs for both ZX5's without a hitch. Is there anything special/different when it's in a DB1?

I'm puzzled and would welcome suggestions/things to check - thanks Nigel

[Andyp]

Nigel, after stripping a set of gears in my DB1 I made the mesh slightly tighter than I would run in my lazer. Also I think the slipper adjustment is quiet important so make sure it's taking some load when under power rather than going straight to the gears.... Touch wood I haven't done anther set in mine !,

[DJ's Dad]

Thanks Andy, good pointers. Can I just confirm that it's the central slipper you are talking about and not slip within the diff?

Interestingly I've just removed the 3-Racing bearing hub carrier and put new bearings in the original Kyosho part and there is noticeably much less play in the input shaft now (side to side). I'll check the forward-aft play and mesh tomorrow. There is only 1 spacer shim washer on the shaft.

Thanks Nigel.

[Andyp]

Yeah the central slipper is what I'm talking about, were the spur gear is...

As far as shims I'm pretty sure my shaft is the std lazer arrangement,I think all I have done on the diff is I have swapped the shims around so instead of having them set to the lazer manual arrangement I have put them the opposite way so I have the two silver shims pushing the mesh slightly tighter. Hope that kinda makes sense

By no means take this as gospel but it should give you some ideas to try

[tomtom]

Never had an issue with diffs in my DB.

If you follow Laser manual it will be a bit tight at first but loosen after a few runs. I put a bit of grease to make it silent and set the slipper a tny bit tighter than Laser manual without issue.

I run the 3racing bearing holder too but I see no point in it. Might damage the case even more so considering the weighted shaft.

I will check the diff case, it might be the culprit. Maybe try a new one as the actual might have some slop causing the issue.

[RudeTony]

Hi Nigel

Don't use the 3racing holder.
If you do the outer bearing casing must be clued to the holder otherwise there is too much play.
Also the pinion shaft does have only the one washer as per instruction manual. This is an alloy shaft and has to be replaced now and again as it wears. If there is any and i mean any play then its a risk the pinion moves to the gear, your will strip the main gears. Always replace in pairs.
There is no known reason to me to mesh any tighter in a DB1 to a normal Lazer.
The slipper is also critical to be tighter rather than looser.
Many make comments that the DB1 is loose in the wet and if fact their slipper is too loose.The slipper then slips and then when it engages there is a snap effect at the rear in low grip.
Tighter is better and far more feel
Hope that helps a little