Pinion gear and ring gear mesh question

[flyboy320]

I am building my Wraith kit, and noticed the diff turns nice and freely as long as I pull on the pinion when I'm turning it. If I push the pinion towards the ring gear, it has a bit of play/slop, and it seems to contact the ring gear more and binds badly when turned. So as long as there is tension on the pinion shaft it works great, it's just when I put pressure on the pinion shaft and try and turn it is doesn't turn as well. Is this normal, is it anything to be concerned about, and can it be fixed?

[vicstag]

I had same problem I just got tiny washers/shims and put them on pinion shaft before install driveshaft that put the pull on the pinion been good ever since

[flyboy320]

Originally Posted by vicstag

I had same problem I just got tiny washers/shims and put them on pinion shaft before install driveshaft that put the pull on the pinion been good ever since

I ended up doing something similar to you. I removed the outer bearing that sits in the housing and placed a few thin shims in the seat where that bearing sits. This had the effect of pulling out the outer bearing slightly and thus preventing the shaft from sliding in the housing to far so it won't bind up any more.

[Revoasian]

You should have some play in between the spur gear and pinion gear. The way I set mine up is when using 48p gears I use a piece of paper torn in a small strip and placed it between both gears and apply a little pressure on the motor towards the spur gear and tighten it down, then pull the strip out. If it doesn't tear your golden. 32p gears I fold the paper in half and apply the same method. Hope this helps.

[flyboy320]

Originally Posted by Revoasian

You should have some play in between the spur gear and pinion gear. The way I set mine up is when using 48p gears I use a piece of paper torn in a small strip and placed it between both gears and apply a little pressure on the motor towards the spur gear and tighten it down, then pull the strip out. If it doesn't tear your golden. 32p gears I fold the paper in half and apply the same method. Hope this helps.

Good advice Revoasian, but to be clear, I am referring to the mesh between the pinion gear and the ring gear located in the differential housing (both the front and rear)...

[Sevastra]

While browsing SuperShafty.com a coupled days ago I learned they are selling thrust bearings now to help with this issue.

AR60 THRUST WASHER MOD - Super Shafty

[maslin]

Use 5mm shims inside the housing between the pinion gear and inner bearing to set the backlash of the gears. Just a little play, not tight.

Then use 5mm shims between the outer bearing and the driveshaft, so you can just get the pin in. You want zero in and out movement of the pinion gear.

[fr8cture]

Originally Posted by Sevastra

While browsing SuperShafty.com a coupled days ago I learned they are selling thrust bearings now to help with this issue.

AR60 THRUST WASHER MOD - Super Shafty

Why is he saying it's Ar60 specific. Wouldn't it work on scx10 axles also...?

[maslin]

Originally Posted by fr8cture

Why is he saying it's Ar60 specific. Wouldn't it work on scx10 axles also...?

Looks to just be a 5x11x4 thrust bearing.

These look much nicer, but that extra .5mm may be too much. I think I'll give them a shot

http://www.amazon.com/Bearing-5x11x4.../dp/B002BBQ604

[STANG KILLA SS]

I run 5mm thick bearings on the outer pinion bearing for this very reason. especially on VP housings. on stock housings mine didnt seem as bad. but i may still run the 5mm thick bearings or shims

i had the same issue, with inward pressure on pinion the axle/gears would bind/lock up. with pulling on pinion the axle would spin freely.

these are what i run. alot easier than fooling with thrust bearings.
http://www.ebay.com/itm/251092804442...%3AMEBIDX%3AIT
http://www.ebay.com/itm/160504687993...%3AMEBIDX%3AIT

[Turtlejon]

Originally Posted by STANG KILLA SS

I run 5mm thick bearings on the outer pinion bearing for this very reason. especially on VP housings. on stock housings mine didnt seem as bad. but i may still run the 5mm thick bearings or shims

i had the same issue, with inward pressure on pinion the axle/gears would bind/lock up. with pulling on pinion the axle would spin freely.

these are what i run. alot easier than fooling with thrust bearings.
5x11x5mm Ceramic Ball Bearing 685 Ceramic Bearing 685 Ball Bearing | eBay
685 2RS Double SEALED Bearing 5mm x 11mm x 5mm | eBay

Those ceramics look nice! Do they handle the sideways force better? And what "fooling" does the thrust bearing need? Is it difficult? Thanks!

[Natedog]

Originally Posted by Sevastra

While browsing SuperShafty.com a coupled days ago I learned they are selling thrust bearings now to help with this issue.

AR60 THRUST WASHER MOD - Super Shafty

Nice.

Originally Posted by fr8cture

Why is he saying it's Ar60 specific. Wouldn't it work on scx10 axles also...?

x2

Originally Posted by maslin

Looks to just be a 5x11x4 thrust bearing.

These look much nicer, but that extra .5mm may be too much. I think I'll give them a shot

http://www.amazon.com/Bearing-5x11x4.../dp/B002BBQ604

Those look very nice.

Originally Posted by STANG KILLA SS

I run 5mm thick bearings on the outer pinion bearing for this very reason. especially on VP housings. on stock housings mine didnt seem as bad. but i may still run the 5mm thick bearings or shims

i had the same issue, with inward pressure on pinion the axle/gears would bind/lock up. with pulling on pinion the axle would spin freely.

these are what i run. alot easier than fooling with thrust bearings.
http://www.ebay.com/itm/251092804442...%3AMEBIDX%3AIT
685 2RS Double SEALED Bearing 5mm x 11mm x 5mm | eBay

I'm getting ready to replace some axle gears with Axial HD stock 38/13 and UD 43/13 gearsets. The stock pinion bearings are 5x11x4mm thick, I don't think stock plastic AR60 housings have enough room to add 2mm more thickness between the inner and outer bearings...would be nice though? You have better results with these 5x11x5mm bearings over the 5x11 thrust bearings?

[Turtlejon]

i had the super shaft thrust bearings for a week, until the front diff started slipping gears and making a clicking noise. i went back to regular bearings...

[Revoasian]

Originally Posted by STANG KILLA SS

I run 5mm thick bearings on the outer pinion bearing for this very reason. especially on VP housings. on stock housings mine didnt seem as bad. but i may still run the 5mm thick bearings or shims

i had the same issue, with inward pressure on pinion the axle/gears would bind/lock up. with pulling on pinion the axle would spin freely.

these are what i run. alot easier than fooling with thrust bearings.
5x11x5mm Ceramic Ball Bearing 685 Ceramic Bearing 685 Ball Bearing | eBay
685 2RS Double SEALED Bearing 5mm x 11mm x 5mm | eBay

This is the set up I use on my VP axle housings, works great and no issues.

[ReconFred]

I have a question, but first Id like to tell you how helpful this site is, wow, outstanding. It looks like STANG KILLA SS's ceramic bearings are what im going with UNLESS someone has gave the 'DLUX AR60 Wraith Bearing Mod' a go, and has good news. Anyone try that yet?

[allanon1965]

Originally Posted by ReconFred

I have a question, but first Id like to tell you how helpful this site is, wow, outstanding. It looks like STANG KILLA SS's ceramic bearings are what im going with UNLESS someone has gave the 'DLUX AR60 Wraith Bearing Mod' a go, and has good news. Anyone try that yet?

DLUX Bearing Mod housing is the way to go, have them and they are great!

[meatmonkey]

It seems that Axial has never cared about giving us the needed shims to properly set ring/pinion mesh. I put together 1:1 ring/pinions, so I'm a bit OCD about ring/pinion setup.

If you just stack up shims outside the housing odds are good your pulling the pinion too far away from the ring gear and actually reducing gear contact and worsening mesh slightly.

You'll need 10x12x.1 to sit under the carrier bearings. If you pull off the bearing caps you'll likely find that the carrier/ring gear can shuck back and forth in the housing quite a bit. This significantly changes gear mesh. Adding shims behind the carrier bearings allows you to precisely adjust where the ring gear sits side/side in the housing.

You'll need 5x7x.1 shims for the pinion shaft. Oftentimes this requires so many shims I'll start with .2m thick shims. I also add solid spacers between the pinion bearings so that once everything is shimmed and the driveshaft is tightened there is literally no slop in the pinion shaft. Once your pinion depth is set, and you solid spacer is installed you put whatever thickness of shims on the outside so the driveshaft buts up snug against them once tightened. The solid spacer I use is from the original generation HPI Blitz rear hub spacer. It was originally used to hold the rear wheel bearings at the proper spacing, allowing you to tighten the wheel nuts without crushing the bearings together. It serves a similar purpose in this application. The solid spacer also helps force the bearings to share loads.

I've found that the stock sintered gears typically benefits from .1-.3mm worth of shims behind the pinion gear inside the housing to bring it closer to axle centerline. Do this before shimming the ring gear/carrier. It seems that for every .1mm you move the pinion towards centerline, you can ditch about .3-.4mm worth of shims behind the ring gear side of the carrier and transfer them to the other side and keep similar gear backlash. This relationship is important to understand, othewise you spend WAY more time swapping shims around to find the sweet spot. The deeper the stock pinions sit to centerline the more of the pinion gear actually contacts the ring gear. More gear contact=stronger.

The helically cut HD gears do not respond similarly, they have a prefered pinion depth to result in the best mesh that can only be found with trial and error. Seems some don't want any shims under the pinion gear, others want .1 or .2, but so far never more.

IMO the stock sintered gears are stronger than most think, but only if they are properly shimmed before being run. They wear quickly if the mesh isn't perfect.

[ussprinceton2004]

^ so, for the helical cut Axial HD gears, running no shims is fine? If not, where and how many shims should I use?

[Natedog]

Originally Posted by Natedog

I'm getting ready to replace some axle gears with Axial HD stock 38/13 and UD 43/13 gearsets. The stock pinion bearings are 5x11x4mm thick, I don't think stock plastic AR60 housings have enough room to add 2mm more thickness between the inner and outer bearings...would be nice though? You have better results with these 5x11x5mm bearings over the 5x11 thrust bearings?

Ditched these after one run in plastic axle housings, they are too thick and gears don't mesh as well, plus they put extra strain on the other regular sealed pinion bearing.

Originally Posted by allanon1965

DLUX Bearing Mod housing is the way to go, have them and they are great!

Originally Posted by meatmonkey

It seems that Axial has never cared about giving us the needed shims to properly set ring/pinion mesh. I put together 1:1 ring/pinions, so I'm a bit OCD about ring/pinion setup.

If you just stack up shims outside the housing odds are good your pulling the pinion too far away from the ring gear and actually reducing gear contact and worsening mesh slightly.

You'll need 10x12x.1 to sit under the carrier bearings. If you pull off the bearing caps you'll likely find that the carrier/ring gear can shuck back and forth in the housing quite a bit. This significantly changes gear mesh. Adding shims behind the carrier bearings allows you to precisely adjust where the ring gear sits side/side in the housing.

You'll need 5x7x.1 shims for the pinion shaft. Oftentimes this requires so many shims I'll start with .2m thick shims. I also add solid spacers between the pinion bearings so that once everything is shimmed and the driveshaft is tightened there is literally no slop in the pinion shaft. Once your pinion depth is set, and you solid spacer is installed you put whatever thickness of shims on the outside so the driveshaft buts up snug against them once tightened. The solid spacer I use is from the original generation HPI Blitz rear hub spacer. It was originally used to hold the rear wheel bearings at the proper spacing, allowing you to tighten the wheel nuts without crushing the bearings together. It serves a similar purpose in this application. The solid spacer also helps force the bearings to share loads.

I've found that the stock sintered gears typically benefits from .1-.3mm worth of shims behind the pinion gear inside the housing to bring it closer to axle centerline. Do this before shimming the ring gear/carrier. It seems that for every .1mm you move the pinion towards centerline, you can ditch about .3-.4mm worth of shims behind the ring gear side of the carrier and transfer them to the other side and keep similar gear backlash. This relationship is important to understand, othewise you spend WAY more time swapping shims around to find the sweet spot. The deeper the stock pinions sit to centerline the more of the pinion gear actually contacts the ring gear. More gear contact=stronger.

The helically cut HD gears do not respond similarly, they have a prefered pinion depth to result in the best mesh that can only be found with trial and error. Seems some don't want any shims under the pinion gear, others want .1 or .2, but so far never more.

IMO the stock sintered gears are stronger than most think, but only if they are properly shimmed before being run. They wear quickly if the mesh isn't perfect.

X2

Originally Posted by ussprinceton2004

^ so, for the helical cut Axial HD gears, running no shims is fine? If not, where and how many shims should I use?

Shim or at least check if all gears need shimming...shim as needed.