Little help with an RC8TE
01-12-2013, 08:12 PM
#1
Little help with an RC8TE
Have an rc8te with very little run time on it (also my first rc in a loooong time). Just redid the center diff with 10k to cut down front tire ballooning (helped a lot). But first run out I developed a "grinding" or "popping" under hard acceleration where it seems to lose a little power. I can not re-create the problem on the workbench. Also when I spin just one tire by hand with the other three & center locked down nothing gives..... so nothing obvious is loose.
So basically just looking for any advice before I start taking things apart as you guys have a LOT more experience than I do.
Also what kind of life can I expect out of my drivetrain? Running 5s mm2200kv on pavement for now???
So basically just looking for any advice before I start taking things apart as you guys have a LOT more experience than I do.
Also what kind of life can I expect out of my drivetrain? Running 5s mm2200kv on pavement for now???
01-13-2013, 01:38 AM
#2
Senior Member
RE: Little help with an RC8TE
ORIGINAL: big JC
Have an rc8te with very little run time on it (also my first rc in a loooong time). Just redid the center diff with 10k to cut down front tire ballooning (helped a lot). But first run out I developed a "grinding" or "popping" under hard acceleration where it seems to lose a little power. I can not re-create the problem on the workbench. Also when I spin just one tire by hand with the other three & center locked down nothing gives..... so nothing obvious is loose.
So basically just looking for any advice before I start taking things apart as you guys have a LOT more experience than I do.
Also what kind of life can I expect out of my drivetrain? Running 5s mm2200kv on pavement for now???
Have an rc8te with very little run time on it (also my first rc in a loooong time). Just redid the center diff with 10k to cut down front tire ballooning (helped a lot). But first run out I developed a "grinding" or "popping" under hard acceleration where it seems to lose a little power. I can not re-create the problem on the workbench. Also when I spin just one tire by hand with the other three & center locked down nothing gives..... so nothing obvious is loose.
So basically just looking for any advice before I start taking things apart as you guys have a LOT more experience than I do.
Also what kind of life can I expect out of my drivetrain? Running 5s mm2200kv on pavement for now???
I also have a funny sound when I drive but my whole drivetrain looks fine except for the stripped wheel hex. I will see if thats the problem when my new set of wheels come in
01-13-2013, 11:41 AM
#3
RE: Little help with an RC8TE
ORIGINAL: Haddi Taha
hey man I have a thunder tiger mt4 g3 which has the exact same drivetrain as your rc8te. I will start by locktiting all the grub screws that hold all 6 of your cvd shafts and the screws that hold the center cvd shaft onto the shaft that holds the diff pinion. Also, make sure the hexagons in your wheels are not rounded off, I made the mistake of not locktiting the wheel nuts and now have a few strippede wheel hexagons. I am running a 2200kv motor on 4s, I wouldn't worry much about the drivetrain on 5s as long as you have all the diffs built right. I have 100k in the center diff and it feels much better then when I had 30k, front wheels baloon less
I also have a funny sound when I drive but my whole drivetrain looks fine except for the stripped wheel hex. I will see if thats the problem when my new set of wheels come in
hey man I have a thunder tiger mt4 g3 which has the exact same drivetrain as your rc8te. I will start by locktiting all the grub screws that hold all 6 of your cvd shafts and the screws that hold the center cvd shaft onto the shaft that holds the diff pinion. Also, make sure the hexagons in your wheels are not rounded off, I made the mistake of not locktiting the wheel nuts and now have a few strippede wheel hexagons. I am running a 2200kv motor on 4s, I wouldn't worry much about the drivetrain on 5s as long as you have all the diffs built right. I have 100k in the center diff and it feels much better then when I had 30k, front wheels baloon less
I also have a funny sound when I drive but my whole drivetrain looks fine except for the stripped wheel hex. I will see if thats the problem when my new set of wheels come in
01-13-2013, 03:54 PM
#4
Senior Member
RE: Little help with an RC8TE
ORIGINAL: big JC
Hey, thanks for the response. Definately not a wheel hex & am fairly certain all my cvd grubs are tight (checked them). I suspect it's the rear diff ring gear/diff pinion gear grinding, but don't have enough experience to know if that's a weak spot, or if it would just fail rather than grind intermittently? When I give a lot of throttle on the bench with wheels raised I can see the rear diff pinion gear bearing begin to slowly spin inthe gearbox. All the guys on that other forum who's name I won't mention but rhymes rcheck, tell me that the mm2200kv on 5s is way too much for the rc8? If that's the case I'm really bummed because on 4s I'm not that thrilled, & was kinda hoping this thing could take a LOT more abuse. Maybe pavement is just to high traction to gun it....
ORIGINAL: Haddi Taha
hey man I have a thunder tiger mt4 g3 which has the exact same drivetrain as your rc8te. I will start by locktiting all the grub screws that hold all 6 of your cvd shafts and the screws that hold the center cvd shaft onto the shaft that holds the diff pinion. Also, make sure the hexagons in your wheels are not rounded off, I made the mistake of not locktiting the wheel nuts and now have a few strippede wheel hexagons. I am running a 2200kv motor on 4s, I wouldn't worry much about the drivetrain on 5s as long as you have all the diffs built right. I have 100k in the center diff and it feels much better then when I had 30k, front wheels baloon less
I also have a funny sound when I drive but my whole drivetrain looks fine except for the stripped wheel hex. I will see if thats the problem when my new set of wheels come in
hey man I have a thunder tiger mt4 g3 which has the exact same drivetrain as your rc8te. I will start by locktiting all the grub screws that hold all 6 of your cvd shafts and the screws that hold the center cvd shaft onto the shaft that holds the diff pinion. Also, make sure the hexagons in your wheels are not rounded off, I made the mistake of not locktiting the wheel nuts and now have a few strippede wheel hexagons. I am running a 2200kv motor on 4s, I wouldn't worry much about the drivetrain on 5s as long as you have all the diffs built right. I have 100k in the center diff and it feels much better then when I had 30k, front wheels baloon less
I also have a funny sound when I drive but my whole drivetrain looks fine except for the stripped wheel hex. I will see if thats the problem when my new set of wheels come in
-stripped ring and/or pinion
-seized bearings
-deformed diff case
-stripped internal diff gears
-make sure everything is running smoothly and is shimmed well
I think and RC8t should easily handle 2200kv with 5s, sure there might be a bit more maintenence but it shouldn't be too bad, it really depends on how you run the truck ans where you run it. High grip surfaces and tries stress the drivetrain, salt water stuffs up bearings, cold make plastic brittle, ect, not everyones experiences are the same. Good luck and I hope you get your rc8t running soon
01-13-2013, 04:20 PM
#5
RE: Little help with an RC8TE
Well I looked it over again, and I see diff fluid(assume it's diff fluid) all around the front gear box. Forgot I drove it into a curb at about 15-20 mph on the first day out with it
, & assume this has something to do with it. I sure hope so, be very dissapointed if this thing can't handle the power I intent to run it on. I will get a chance to take it apart tonight or tomorrow & I'll let you know what I find. Thanks for the input Haddi Taha I appreciate it, btw, how would I determine if the gearbox is warped??
-also plan to ditch the 5200mah 5s hardcase for a 3300mah softcase which should drop about a pound ,so that should help with drivetrain stress.....
01-13-2013, 10:02 PM
#6
Senior Member
RE: Little help with an RC8TE
ORIGINAL: big JC
Well I looked it over again, and I see diff fluid(assume it's diff fluid) all around the front gear box. Forgot I drove it into a curb at about 15-20 mph on the first day out with it, & assume this has something to do with it. I sure hope so, be very dissapointed if this thing can't handle the power I intent to run it on. I will get a chance to take it apart tonight or tomorrow & I'll let you know what I find.
Thanks for the input Haddi Taha I appreciate it, btw, how would I determine if the gearbox is warped??
-also plan to ditch the 5200mah 5s hardcase for a 3300mah softcase which should drop about a pound ,so that should help with drivetrain stress.....
Well I looked it over again, and I see diff fluid(assume it's diff fluid) all around the front gear box. Forgot I drove it into a curb at about 15-20 mph on the first day out with it
, & assume this has something to do with it. I sure hope so, be very dissapointed if this thing can't handle the power I intent to run it on. I will get a chance to take it apart tonight or tomorrow & I'll let you know what I find. Thanks for the input Haddi Taha I appreciate it, btw, how would I determine if the gearbox is warped??
-also plan to ditch the 5200mah 5s hardcase for a 3300mah softcase which should drop about a pound ,so that should help with drivetrain stress.....
A warped gear box is when the diff housing has melted a bit, the positions of all the shafts and gears can be changed causing misalignment then ultimately, more friction and noise. A warped gearbox can happen when you have excess friction nearby causing heat hot enough to deform the plastic housing like a seized bearing or having way too many shims.
01-22-2013, 08:41 PM
#7
RE: Little help with an RC8TE
Finally got a chance to wrench on it tonight and wanted to check in & conclude what I found ( I hate unresolved threads). I had a deracing bumber on it which goes under the gearbox. So apparantly when I smacked the curb with the front bumber it acted as a wedge and drove the gearbox up enough for the tabs that hold it together to come out of the chassis and thus my gearbox seperated a little. Under power this allowed my diif outdrives to wiggle around and the gears skip. I am quite impressed as there is no damage to the gears at all and my confidence in this thing handling serious power is restored. However not so sure on deracing products now. The way the mudd guards attach is flimsy (already lost one) and I don't want a repeat with the front bumber.
02-01-2013, 09:18 PM
#8
RE: Little help with an RC8TE
Well, finally got it all back together and got a chance to run it today (Oregon rain mang!). Guess what..... problem still there...boo.....! So I kept running it into the ground so the problem would jump out me and it turned out to be the center diff gears. One of the diff sun/planet gears was ground down, it was hard to see at first. So long story short I am again paranoid that this thing won't hold up to the power I want to put through it....we'll see I guess.
In the process of converting my dnx 408 to electric and run the exact same setup through it. I can tell just by looking that all the steel parts on the Durango are of a significant higher grade.
02-04-2013, 02:03 AM
#9
Senior Member
Join Date: Mar 2005
Location: Kingston UK, but living in Athens, GREECE
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RE: Little help with an RC8TE
That car has a drivetrain that can take anything, don't worry, rebuild it carefully and it'll be fine. You used 10k to cut down on tire ballooning? Do you mean 100k? I use 20k for racing, 10k is very light, but will keep the front tires down and ballooning. 100k will stop the tires ballooning (at least not much more than the rear), but make it infinitely more difficult to keep them on the ground.
02-04-2013, 07:45 PM
#10
RE: Little help with an RC8TE
Yeah, I'm still figuring out the effects of diff oil weight. I tend to read a LOT before buying or setting upmy stuff and diff weight is one of those things that's all over the map on the forums. What I can say is the 10k in the center made a substantial difference for the better compared to what was in there.
When I was figuring out how to program my esc the car went from all most full throttle to reverse on the workbench and for now I chaulk up the roached gears to that. Anyway got new gears and diff housing on the way along with some lighter batteries so I'll keep at it for now.
When I was figuring out how to program my esc the car went from all most full throttle to reverse on the workbench and for now I chaulk up the roached gears to that. Anyway got new gears and diff housing on the way along with some lighter batteries so I'll keep at it for now.
03-16-2013, 01:06 PM
#11
RE: Little help with an RC8TE
Wanted to check in & post what I found (don't like unresolved threads)
So it looks like one of the sun gears in my center diff never finished the machining process. The teeth on the gear came to a point instead of machined off to a bevel (flat) like the other gears. Didn't notice this until I got the new ones and took a hard look at them. Kinda weird, wonder if a whole batch of them went out like that.
Anyway she's up and running and has taking a beating. Really cooks on 5s wow!
