Spec-R Gear diff review
11-13-2011, 04:19 AM
#875
Tech Rookie
If your gears keep stripping then it is a sign perhaps that the teeth are not correctly meshed and /or there is excessive float on the gears. Measure the widths of the pinions and side gears just to make sure they are all the same. With the high RPM and torque being transmitted through the diff it is critical that all the components are correct and meshed uniformly or the tooth loading may be too high in one area which will cause them to strip.
One other aspect of the diff to be aware of is that the internal ratio is above 1:1 unlike a ball diff, which means the unloaded wheel can rotate faster than the pulley. If the process of unload to load is smooth then everything can be okay but if it is sharp and fast, as in hitting a bot dot or a curb on power then this will apply a large spike on the diff and could cause problems.
A combination of carbon side and nylon pinion or the other way round may be better, but that is for someone to try.
One other aspect of the diff to be aware of is that the internal ratio is above 1:1 unlike a ball diff, which means the unloaded wheel can rotate faster than the pulley. If the process of unload to load is smooth then everything can be okay but if it is sharp and fast, as in hitting a bot dot or a curb on power then this will apply a large spike on the diff and could cause problems.
A combination of carbon side and nylon pinion or the other way round may be better, but that is for someone to try.
11-13-2011, 01:31 PM
#877
If your gears keep stripping then it is a sign perhaps that the teeth are not correctly meshed and /or there is excessive float on the gears. Measure the widths of the pinions and side gears just to make sure they are all the same. With the high RPM and torque being transmitted through the diff it is critical that all the components are correct and meshed uniformly or the tooth loading may be too high in one area which will cause them to strip.
One other aspect of the diff to be aware of is that the internal ratio is above 1:1 unlike a ball diff, which means the unloaded wheel can rotate faster than the pulley. If the process of unload to load is smooth then everything can be okay but if it is sharp and fast, as in hitting a bot dot or a curb on power then this will apply a large spike on the diff and could cause problems.
A combination of carbon side and nylon pinion or the other way round may be better, but that is for someone to try.
One other aspect of the diff to be aware of is that the internal ratio is above 1:1 unlike a ball diff, which means the unloaded wheel can rotate faster than the pulley. If the process of unload to load is smooth then everything can be okay but if it is sharp and fast, as in hitting a bot dot or a curb on power then this will apply a large spike on the diff and could cause problems.
A combination of carbon side and nylon pinion or the other way round may be better, but that is for someone to try.
It was my first attempt so they dont keep stripping, but I have heard lots of bad reports re the durability of the spec-r. When I rebuilt with the new gears I added additional shims. I may even add another yet as its not binding (I'll shim it until its just binding then take take some material off the gears until its smooth)
I'd still like some information on the different gear materials. Anyone able to shed some light on this?
11-14-2011, 04:44 PM
#878
Spec-R diffs running Mod
Thanks for the advice.
It was my first attempt so they dont keep stripping, but I have heard lots of bad reports re the durability of the spec-r. When I rebuilt with the new gears I added additional shims. I may even add another yet as its not binding (I'll shim it until its just binding then take take some material off the gears until its smooth)
I'd still like some information on the different gear materials. Anyone able to shed some light on this?
It was my first attempt so they dont keep stripping, but I have heard lots of bad reports re the durability of the spec-r. When I rebuilt with the new gears I added additional shims. I may even add another yet as its not binding (I'll shim it until its just binding then take take some material off the gears until its smooth)
I'd still like some information on the different gear materials. Anyone able to shed some light on this?
The black carbon gears last longer, any were from 3 to 12 runs, depends on how bumpy the track is from what we have found, use a .2 and a .1 shim each side, use a 1:1 car CV grease on the seals, this works very well for stopping the oil from leaking out of the outdrives and use Tamiya aint-wear grease on the gasket as well.
we have not striped any of the carbon gears but have cracked a few sets, I have had emails to and from Spec-R and told them that there pin slot is too deep and that is why the gears are cracking, I don't know if they are going to look at changing it or not.
Regards
Gary
11-14-2011, 05:36 PM
#879
Hi
The black carbon gears last longer, any were from 3 to 12 runs, depends on how bumpy the track is from what we have found, use a .2 and a .1 shim each side, use a 1:1 car CV grease on the seals, this works very well for stopping the oil from leaking out of the outdrives and use Tamiya aint-wear grease on the gasket as well.
we have not striped any of the carbon gears but have cracked a few sets, I have had emails to and from Spec-R and told them that there pin slot is too deep and that is why the gears are cracking, I don't know if they are going to look at changing it or not.
Regards
Gary
The black carbon gears last longer, any were from 3 to 12 runs, depends on how bumpy the track is from what we have found, use a .2 and a .1 shim each side, use a 1:1 car CV grease on the seals, this works very well for stopping the oil from leaking out of the outdrives and use Tamiya aint-wear grease on the gasket as well.
we have not striped any of the carbon gears but have cracked a few sets, I have had emails to and from Spec-R and told them that there pin slot is too deep and that is why the gears are cracking, I don't know if they are going to look at changing it or not.
Regards
Gary
08-30-2013, 03:10 PM
#882
Do these gear diffs 38T Gear diff for Xray T2/T3 fit into the Xray T2'008?
Running stock motors, should I get the carbon gears, or will the nylon ones be ok? Also, do they now come with the version 2 gasket, or will I need to buy those separately?
Running stock motors, should I get the carbon gears, or will the nylon ones be ok? Also, do they now come with the version 2 gasket, or will I need to buy those separately?
08-30-2013, 11:01 PM
#883
dan the gears are junk
6 runs in stock and they blow
6 runs in stock and they blow
08-30-2013, 11:40 PM
#884
08-30-2013, 11:46 PM
#885
Shimming was key on my shui. And don't over-sand the gears. One big shim under each big gear. Small shims on the outside of the case, between the case and outdrive to remove the slop. It should feel notchy but not bound up when new. After a run or two it should be smooth.
That being said, having built an Xray diff for my T4, don't waste time with Spec-R. The xray one is that good. Slap it together, no sanding or anything, and it's perfect from the first run.
I might consider a spec-r for the front, though.
-Mike
That being said, having built an Xray diff for my T4, don't waste time with Spec-R. The xray one is that good. Slap it together, no sanding or anything, and it's perfect from the first run.
I might consider a spec-r for the front, though.
-Mike