Drivetrain Woes
 

I just finished installing the extended wheelbase suspension arms on my E-revo and i like what it has done to the handling, but on is maiden voyage i sheared both of the drive pins and broke one on the rear sliders. After some inspection i decided to put brand new drive shaft assemblies on the rear as the one that didn't break was looking pretty worn. well with the batteries topped off i headed out again and got in a good run until my pinion set screw came loose, i headed back to re-locktite and reinstall and while doing this i noticed that my brand new sliders were showing some extensive wear after maybey 15 min of driving....not cool.

Is this just something to expect with a relatively high power motor/esc combo and the extended wheel base just creates more stress?

Also, i dont know of any good cvd's for the revo, i know there are some out there but i haven't heard of any that really stand up to power. I would easily pay top dollar for a set that is bombproof but i dont know of any that are.

sorry for the long explaination!!!

Sounds like any METAL driveshafts would work much better than the stock sliders. The holes around the U-joints will inevitably wear out anyways, even if the rest of it holds up.

How "extended" is it? Would these still fit? http://www3.towerhobbies.com/cgi-bin...&I=LXNTT8&P=ML MIP makes great stuff. They should hold up alright.

put the stock arms back on and use some 1/2 offset rims! Dramatically improves handling! I have only managed to break one new driveshaft on my E-REVO. That was on the stock rims and talons running 6s. I made a driveshaft out of all the used pieces I have from my previous trucks but snapped that on 5s when I was doing a cartwheel and kept punching it trying to pull out of the cartwheel, but it was the same shaft that was made up of used parts so I don't know if it was already damaged.

Also it has been pretty well documented on here that the stock sliders will hold up to pretty much anything a metal one will.

i would think that too, but i've heard several people on here say that the traxxas cvd's have issues popping out on the drive cups, especially when used in conjunction with RPM arms which flex more, not sure about the MIP ones though. The arms in the back give 10mm or 19mm longer wheelbase, i am currently using the 19mm setting. As i said before this makes the truck drive noticeably better as it doesn't wheely with anything over 1/2 throttle, instead it just GOES!!!

already have the 1/2 inch offset rims with badlands, and the stock rear arms would put me back to where i was....i like how the thing drives now, i just don't want to have to replace the sliders after every run.

well im suprised you are haveing problems with the sliders, mine still look new after 5 races, the traxxas cvds hold up well and they are cheep compaired to the price you would pay if bomb proof made some, just rember to buy extended out drives for the read diffs

so bombproof makes some cvd's? Im really don't mind paying a lot as long as i am getting a good reliable product. i just don't wand to drop money on the traxxas or MIP ones and still have issues with them

Information.
 

Try talking with Dan at Kershawdesigns.com. He may be able to help you with the drive shaft/axles that you need, or even make something up for you. Personally speaking plastic is just what it infers, and plastic toys were made for boys. If you want to beef up your truck by putting more power then was originally installed by the MFR, plus adding extended arms, offset rims, and such, then why try depending on plastic parts to drive the modifications? Once you modify the power plant or the drivetrain in any way you might as well take a very close look at the rest of the truck and anylize what you have done. Surely there will be more weak lincs that need to be modified/upgraded in order to truly make the vehicle Bombproof as you wish.

Bottom line, you can either purchase plastic parts and routinely replace them due to breakage or bad driving, or upgrade your vehicle engineering wise making good purchases up front ONCE, and enjoy having fun with your truck knowing that it will hold up to just about anything you throw at it. All of this is contingent upon your use of the vehicle, wheather you are ROAR racing or bashing your vehicle in yoru own backyard. How many real life size vehicles do you see using composit plastics in the drivetrain?? Size to weight ratio these vehicles are under the same stresses and should be engineered in the same manner. Sure you can use plastic driveline parts all day long and maybe it will hold up for a while, but in the back of your mind you are still going to be thinking about wheather or not it will hold up, which will affect your willingness to go full throttle and really push your truck the way you would like. RC Alloys.com also does custom drive shaft work on request. Have fun and good luck with your decisions. Spend your money wisely, but realize that this hobby is not cheap by any means. You are going to spend big money over the long haul no matter which way you go with this project.

I have to think you have something else going on here. What kind of "wear" did you see that made you concerned? Are the shafts rubbing on the arms? Did you change your rockers and pushrods to the correct ones for use with the extended wheel base arms? (you can't use the LT's with those, right?). You have a symptom that may or may not be resolved with higher priced CVD's, but you may also end up spending that money and still have the issue.

BTW: If you have seen any of Jerry's stuff, he has an extreme allergy to anything plastic!!!!

I have been running my revo with all its plastic day in and day out on 6S, and they have been holding up better than my metal CVD's did.

Ahhh! Language barrage! :tongue:

basically the holes in the ends of the sliders where the metal U-joint fits in are getting stretched and ovalized in a relatively short time. the shafts themselves seem to be holding up fine as i have only cracked one....its always the ends that give out.

Traxxas Cvds fixes that but then you may trash your diffs...

Good thought! I would rather be replacing a shaft that takes less than 5 minutes than the hour required to change out a diff. I have picked up driveshafts on ebay for about $5 each. I went through alot of them on my T-Maxx and Revo 3.3, hitting things doesn't help:whistle: I was a noob once too:yes:

That's the cycle of upgrading. Replacing one part causes failure in another, so you replace that, and so on up the line until things don't break anymore! :yipi:

There will always be a weak link, no matter how much upgrading you do! It's best to keep the weak link at a point that's easy to get to and cheap to replace.

Ahh but, when everything is upgraded, that "weak" link may be strong enough. Or enough so that failures are few and far between.

eventually i will be putting in the RCM hybrid diffs as i have already torn up a stocker and had to replace it. i will have to look into kershaw designs and see if they might be able to fab something up for me driveshaft wise.

Look at it this way, wheelies are not as hard on driveshafts as the great grip and leverage that the extended wheelbase puts on the truck. I would set your slipper slightly looser. Not much. Also limit your full throttle starts on high traction surfaces.

I am currently working on putting lst diffs in the revo bulks... Sorta budget way to get bulletproof diffs.

thats pretty much what i have concluded, and i have seen your post on the lst diffs, seems like a cheaper alternative to the RCM diffs. funny about the slipper, my last drive it started slipping excessively, when I brought the motor in i checked the temp and it was 200!!!! hopefully its not toast, ill check tomorrow, but the slipper was missing one of the pads when i looked...so guess thats an easy fix at least

edit: my slipper has been locked since i installed the new motor/esc and batteries, but ill try to loosen it so it actually works!

hey! I was thinking the exact same thing. I have a muggy, and when I replaced the stock plastic outer diff case with aluminium cases I noticed they'll probably fit in the revo bulkhead. Just don't feel like taking my revo apart right now. How far are you?

I am worried about the diffs in my erevo with the mmm combo. I loved the lst diffs(I could rum my elst2 50+mph and never had to worry about diffs or driveshafts! The diffs and driveshafts are my main concern with my erevo. I just want it to be as reliable as the lst2 was.

Well I got the mmm combo in my e-revo with low timing, low starting power,and 70% punch control! I ran 1 battery out and after 2 mins into the second set my brand new driveshafts broke! My slipper is pretty loose too. I need a set of driveshafts that will hold up and wear like my lst2 ones did. So how makes the toughest longest lasting cvds!

EDIT| I also have the extended rear arms!

welcome to my world....1 run usually puts at least one driveshaft out of its misery, even if its brand new. Like i said before, i would easily pay big money for a virtually bullet-proof cvd and center drive-shaft set.

shizzon do you have durabilaty issues with the traxxas extended rear arms? Mine wont take a bad landing. I am on my 3rd set :( ! When they broke the landings were on one wheel but it wasnt that bad???
I am looking at getting the tekno extended rear arms to see if they will hold up better.

Also went threw another stinking driveshaft today. The other rear one doesnt look like its going to hold much longer. THIS STINKS! I wonder if the new summit cvds will hold up better since they were designed to take lots of torque at extream angles?

I havn't had any issues breaking the extended wheelbase arms, though when i tried to move the pivot balls to th 10mm setting the arm cracked at the thread.yeah it might be worth giving those a try as mine break at the ends and that appears to be what is beefed up on the summit's axles.

mine break at the ends too

Man 4 batteries down and 5 driveshafts gone. I am now at 90% punch control. This freakin blows. If the new BE e-revo comes with these driveshafts there is going to be alot of upset owners( I know I'm not happy at all) I just want something relieble and dont want to go threw 4 different brands to get it b/c I'm not rich!

Have You Tried???
 

Have you tried contacting Dan at Kershaw Designs yet:eyes:. Even if he does not have what you need he can have custom stuff made up. It's worth a try.:yes:

To be honest with you I haven't...I am completely out of money unfortunately. Basically my girlfriend hasn't received her loans for school (it is the end of the term) because of a stupid issue where her SS# showed that she was deceased, and as far i I know they don't give loans to deal people. So anyways I have basically been paying for alot of her needs from my loans and i have run out unfortunately. perhaps after Christmas, or sometime next term, but as of right now im just trying to eat and get over this horrible throat infection that i have.

The BL edition has the new driveshafts like the Summitt will have. They should be an improvement over the current driveshafts. Are the extended rear arms swept back too far to run CVDs? A poorly-built drivetrain is the #1 reason I sold my BL Revo and got a Truggy (Losi Muggy, weak control arms but you can't kill the drivetrain).

My brushless lst2 had a bulletproof drivetrain! I am hoping I can get this revo that way or I will have to get rid of it. I will see what dan at kd has to offer. It will have to wait until after christmas b/c I'm broke too!

Well I picked up a set of vantage racing cvds and they fit with the extended rear arms. I will find out how durable they are this weekend. I am just happy they fit without issues!:smile:

Well 3 runs and the pop metal vantage racing cvds all broke! The plastic ones are holding up better. Man I am pissed. I just wasted money on junk !

Instead of blaming all the different shafts that you continue to break, you might want to consider that you "wasted" you money with those extended arms. Just a thought.

Tell me why the front ones broke first and how the he11 does that have anything to do with the extended REAR arms? The rear ones held on the longest. I dont see how with what little power I am putting out it is snapping metel shafts.

I would easly take off the extended rear arms if I thought thats what broke the cvds but no way was it the arms! I have also moved my arms to the 10mm instead of the 19mm (to help with turning)

Can you post a pic of the busted CVDs?

If you are on the brakes really hard that could put some stress on the shafts, but they should have held up longer than 3 runs.

My motherboard died on my computer so I am on my wifes wii system. So I cant post pics until I can get to my brothers house. Will try tomorrow! I have my brakes set to 35% now so they dont grab hard. Also have my punch on 100% and my slipper loose. I would really have to try to even get a wheely. The fist one broke just turning in the yard 3 mins in on there first run. The others broke running on the track.

Well, its going to be tough for us to diagnose on here, but as stated before, pics would help.
Something other than the shafts is causing your issue. You have broken far too many compared to what others are experiencing - and your not running any more power than most others here.
Recheck all of your suspension. Make certain the arms are all on the right direction (I found out I had been running my RPMS upside down after a year of running it - even though I know I double checked it). see if you might have bad bearing in the axle carrier, or possibly the wrong bearing, that would allow excessive slop in the axle.
Since this one was a front, was its damage different than when you broke the rears? I experieced bent metal shafts when I ran them with RPM Arms, thus I converted to plastics, and havent experienced any problems (other than loosing C-clips).

You just have to take a step back, and remember that often the symptom is not the cause of the problem!

This is exactly why i didn't go out and buy a set of cvd's, it seems that they dont do much for durability. I also contacted Dan at Kershaw designs as he pretty much said that he would not be able to make anything better that whats out there.

It seems like the best alternative would be to see how the Summit drive shafts hold when they finally com out. I wish a high caliber company like UE would come out with a set, but it seems like the dont come out with new products anymore....

Unfortunitely.
 

:yes: Yea unfortunitely Robin at UE said that making stuff for the R/C community just was not proffitable anymore, hence nothing new or even anything for replacement parts available. From all of the garb on the forums it seems that he has moved on to the harley Davidson hop-up products to make his fortune. That is a very sad thing for us. UE is the best stuff out there.

Why don't you try talking with Bill at RC alloys and see if he would be willing to fab something up that everyone could use in that class? He will need specific measurements and maybe a sample of what you want, but he is pretty resourceful with his business. Or even talk with MonsterMike here at RCM and see if he can help. That is what these guys do. :yes: