AR44 Overdrive Diff Gears

[mikebecher]

My AR44 diff gears arrived today! The part description is Xtra Speed Steel Heavy Duty Helical Spiral Gear and Pinion Gear for Axial SCX10 II and the part number XS-SCX230064.

These are definitely 28t/8t ratio (3.5:1). Paired with the standard 30t/8t ratio (3.75:1) in the rear, there's a front/rear drive difference of about 6.7% which is about half as much as the AR60 OD gears.

Tonight I'll pull the stock gears out of Levior and get a comparison before installation. Here's what they look like out of the package, minus the e-clip which is pretty standard.

[mikebecher]

Installation of the Xtra Speed OD diff gears is complete in the front diff of my Bomber (with AR44's). Before I reassembled everything I cleaned up the stock gears and took some close-up photos for side-by-side comparison. In general, the machining and finish on the Axial gears is higher quality but other than that they are almost identical (aside from the one-piece design). Every dimensional measurement I made was within .02 mm which is probably as close as I can get with my digital calipers. The stock diff gears weigh 26g and these are 21g. Bearing and shaft fits were nearly identical and the feel of the gear mesh was very close to that of new stock gears (a little 'crunchy' but generally free spinning). There is an e-clip meant to go onto the exposed end of the pinion shaft but I found with it installed the WB8 driveshaft would not fit properly.

All in all this seems to be a good fitting, quality option to hold us over until Axial gets their act together and releases their own gears. I plan to conduct a trail test tomorrow and will see if the meager 6% overdrive makes any noticeable difference.

In all photos, the stock gear is on the right and the new overdrive gear is on the left.

[Drock123]

Had a chance to run it yet?

[mikebecher]

Originally Posted by Drock123

Had a chance to run it yet?

Yup, I ran it for about an hour today at lunch but it seemed a rather routine test. Nothing broke, seized or slipped and the overdrive advantage was hard to discern. There was slightly less pushing through corners and just a bit of extra pull when climbing but the overdrive is much less noticeable than in the AR60s.

[wrightcs77]

I ordered three pairs of these for my rigs I hope they are okay

[quark]

Originally Posted by mikebecher

Yup, I ran it for about an hour today at lunch but it seemed a rather routine test. Nothing broke, seized or slipped and the overdrive advantage was hard to discern. There was slightly less pushing through corners and just a bit of extra pull when climbing but the overdrive is much less noticeable than in the AR60s.

I'm insterested to know how well does it combat the torque twist? 6.7% isn't that much, but might help. Take it up a at the limits and see if that left front wheel lifts, and the back right swats down.

[mikebecher]

Originally Posted by quark

I'm insterested to know how well does it combat the torque twist? 6.7% isn't that much, but might help. Take it up a at the limits and see if that left front wheel lifts, and the back right swats down.

I've noticed a very slight improvement in torque twist. But my rig is so far from the norm I'm not sure how much this would apply to a typical 10.2.

[GLwagon]

Just ran mine first time today, and a little rock hopping & it has chipped some ring teeth clean off. (pics soon)

They are less durable than the stock Axial.

One piece ring and spool

[Waitwhatsthat?]

I got less than an hour before mine were trashed.

Sent from my XT1585 using Tapatalk

[Ambis]

Mine after one 1600 mAh 3S (maybe 30 mins) with 4 kg Class 1:

Bigger image: http://i.imgur.com/JFp8OpD.jpg

Absolutely useless! Truck felt absolutely beautiful after Yota II's. But now I'll just have to wait for a set of proper gears... Maybe even have to put the Yotas back on. Ahh crap.

[GLwagon]

Soft metal & 1/2 worn out

[MattySlimz1987]

These Xtraspeed OD gears sound like some REAL cheap Chinese pot metal. I had been checking them out recently because of the price and looks. But those 2 things alone can obviously be deceiving. I had wanted to find out more about how they were performing with these good sounding ratios and am glad I saw this, unfortunately they didnt hold up for a lot of you, but gives me more hope in my instinct as this very well could have been another impulse purchase because it was in my cart.

[thurlo]

I ordered a set of xtraspeed diamond axles and was expecting to get the one piece spool and locker but was surprised at what I found. This could be an alternative overdrive front axle assuming they continue to hold up. Gearing is 28/9. I will be updating after I run a few more packs through. I should add that the gears out of the xtraspeed complete axle are not compatible with stock gearing. EVERYTHING else can be interchanged though.

Xtraspeed Complete scx2 axles!