XV-02 oil filled gear diff

[Pylon80]

... Are there any metal bevel gears compatible with the XV-02 oil filled gear diff 22049?

Thank you!

[Nicadraus]

Not sure but the diff bevel gears are the same to what the XV-01/TA-06/FF03/4 uses. It looks very similar though. If so, then there's a steel gear available for it.

[Pylon80]

46 minutes ago, Nicadraus said:

Not sure but the diff bevel gears are the same to what the XV-01/TA-06/FF03/4 uses. It looks very similar though. If so, then there's a steel gear available for it.

I looked into these but they are different  TA-06 small bevels for instance have 12 teeth compared to only 10 teeth for the new XV-02.

[Honza]

 TB-04 or TA06 steel bevel set don't fit. And XV-02 has different bevel gear set from TRF420 and derived models.

Early oil filled diff in TT-02RS used #51144 TG-10 gear set. Since XV-02 diffs are similar, maybe that could fit? Unfortunately that PN is not present in any Tamiya matching set, so I cannot confirm it.

[Pylon80]

4 hours ago, Honza said:

 TB-04 or TA06 steel bevel set don't fit. And XV-02 has different bevel gear set from TRF420 and derived models.

Early oil filled diff in TT-02RS used #51144 TG-10 gear set. Since XV-02 diffs are similar, maybe that could fit? Unfortunately that PN is not present in any Tamiya matching set, so I cannot confirm it.

I have the TG10 gears, they are actually the same as the older TT-02 diff (the one you would find in a RR kit) and they are of a different tooth count. But who know, they could be a different module but same outside diameter and bore and actually fit. I will give it a try!

[Honza]

10 hours ago, Pylon80 said:

But who know, they could be a different module but same outside diameter and bore and actually fit. I will give it a try!

If they are coarser module, they might be even stronger. In the worst case, you can fit the entire differential.

[Honza]

found this video that compares TGS Vs XV-02 gear diff. The parts are not interchangeable...

[Pylon80]

12 hours ago, Honza said:

found this video that compares TGS Vs XV-02 gear diff. The parts are not interchangeable...

Yeah, I have the 2 diffs featured in that video. The XV-02 diff actually uses the bevels from the TRF420 diff (as I recently found). That TRF diff is only used at the rear (per the last 10 years' or so trend in TC: oil filled at the rear and spool at the front) and it has proved to be reliable even in the high power classes. So I would not be surprised if Tamiya never released metal gears for it.

The quirky part of me just thought metal gears would have been a cool addition to the XV-02 diff but I don't think that makes a lot of sense anymore, mechanically. So I will simply stick to the stock gears

[Honza]

45 minutes ago, Pylon80 said:

The XV-02 diff actually uses the bevels from the TRF420 diff (as I recently found)

I thought that, too, but XV-02 uses a different PN (10015174) and TRF gears (51567) aren't shown as compatible in the parts matching list...

I recently found out that buggy racers run only 2 small bevel gears on dirt. Interestingly that's exatly the setup of TT-02 metal differentials, although I'm not sure what's advantage of that solution

[Pylon80]

17 minutes ago, Honza said:

I thought that, too, but XV-02 uses a different PN (10015174) and TRF gears (51567) aren't shown as compatible in the parts matching list...

I recently found out that buggy racers run only 2 small bevel gears on dirt. Interestingly that's exatly the setup of TT-02 metal differentials, although I'm not sure what's advantage of that solution

Interesting about the different part number. Perhaps different material, same tool?

I just found out about buggies using 2 bevels too!  I think what it does is make the diff a little lighter at the expense of a little bit more play/less smoothness?

[Honza]

10 minutes ago, Pylon80 said:

Interesting about the different part number. Perhaps different material, same tool?

I'd love to know that too. And if it's a different material, is it better or worse? Or maybe there's just a little difference in tolerances...

12 minutes ago, Pylon80 said:

I think what it does is make the diff a little lighter at the expense of a little bit more play/less smoothness?

My guess is, that two gears, will cause less increase in locking force at higher left/right difference speed. Alternatively, similar to Tamiya, recent buggies use ball diff again, which has more or less constant force regardless of speed difference.

Funnily enough, years ago, I found that my rally TB03 was faster with ball diffs than gear diffs. Back then, I though it was because of poor quality of 3rd party gear diff (it was before TB-04), but it seems, that there's something good about ball diff on low traction.

[Pylon80]

22 minutes ago, Honza said:

that there's something good about ball diff on low traction.

Right, I think TLR were making a carpet version with an oil-filled gear diff and a clay version with a ball diff, on one of their buggies.

[Honza]

9 hours ago, Pylon80 said:

Right, I think TLR were making a carpet version with an oil-filled gear diff and a clay version with a ball diff, on one of their buggies.

X-ray does that too with XB2

[Man1c M0nk3y]

10 hours ago, Pylon80 said:

think TLR were making a carpet version with an oil-filled gear diff and a clay version with a ball diff, on one of their buggies.

IIRC Schumacher do this with the LD3 variants with the LD3S (stock) & M (mod) versions coming with a gear diff and the LD3D (dirt) coming with a ball diff. 

Again, IIRC they did this back when I got my Cougar KD (dirt) with ball diff and KC (carpet) with gear diff. 

[Howards]

I thought folks were using geared diffs on high grip not because they are in some way better in action, quite the opposite in fact, but because set-up is repeatable and has a wider working window. The viable window for a ball diff in a high grip track is really narrow because the surface is so grippy, and once you've dialled it in you are only a few races from rebuilding it and the set-up isn't easily repeatable.