Hey,
Is there a substitution for this part that will not break at the wheel so easy? I have read how to strengthen
at the cup but not at the wheel.

Thanks as always

I dont think there are any aftermarket options other than CENs' own replacement cvds'. If you keep track of the thread titled 'Tmaxx wheels have arrived', Poor Judgement is experimenting with different cvds from HPI. I am sure he will update everyone with any progress he makes. Until then you could always try to straighten them.

I have tried to find a replacement but not successful yet.... I'll wait till poor judgement's findings to continue with mine... what did you hit to bend the drive shaft like that.. usually bend at ends.... that is easy to bend back as the metal cen uses is fairly bendable... at around $30.00 for the pair make them last...

dont hold yer breath guys... this is gonna take a while to find out about these shafts. havent heard anything from titanium racing yet, nor has my message appeared on their message board...

im sortin out my new house at the mo, so my priorities have shifted a bit im afraid, i will find out what i can, obviously, but like i say - its gonna be a while yet i reckon.

who was it who had one of the savage shafts on order to try out? i forgot who it was, was it someone on this forum? lol, me brain is lost amongst all these plasterboards....

while we are back on the shaft subject - could someone measure up the cen mt shafts, and post the measurements on here, as, embarrasingly, i still only have the rally shafts here. the more info i have to work with - the better.

My MT shaft measures (from drive pin center) as follows: Length 1 = 89.55mm, Length 2 = 92.75mm, Diameter = 9.95mm.
I believe the rally shafts are more resistant to torsion than the MTs because they are shorter.

thanks for that mate - i am gettin there slowly in the hpi forum in the monster truck section - well... i think im gettin somewhere

thats just the info i needed. thanks for takin the time to do that.

and yea, the rally shafts dont suffer as much, but with my .18 engine, i am suffering with twisted rally shafts as it is, so, like u say, i expect more trouble with the mt shafts unfortunately, which is mainly why i havent paid for any yet - besides the fact that they are way over priced for the quality of them...

I am hoping something will fit that is stronger than the stock.... I wish MIP would make something,but not yet....

I hate to bring up an old thread. But, looking back to the first post here I notice that the shaft is bent and broken. Now, the break more than likely happened b/c of a bend in the shaft itself. I had a pin at the cv break off and I fabbed a new pin out of a small nail. When I put it back together I noticed the shaft was bent a little from a previous wreck I had. I straightened the shaft on a flat surface w/ a small hammer and used a short ruler for a straight edge. The pin broke b/c I did not notice the shaft was bent after the wreck. I have ran 4 tanks through since I fixed it and no problems. I can't help but think that a lot of these shafts breaking is caused by people not checking their shafts for straightness on a regular basis. These shafts can be straightened very easily and replaced if you can't straighten them. If you repair them b/4 they break you will lessen the chance of breaking a diff cup. Vibration is the worst enemy for these components. If you have had a front end wreck make sure to check the shafts for straightness. All you have to do is hold the truck in the air and spin the wheels slowly. You will be able to see the shaft dip a bit if it is bent. If it is replace it or fix it b/4 you drive again.
I have found this truck to be pretty strong but there are some spots that need stiffening. I don't think these shafts or the diff cup are weak spots at all. But if you don't keep an eye on them they will become weak.
A couple of things that should be first on everyone's list. Stronger steering servo, locknuts on engine mount bolts and always use loctite, make brace for the brake mount or buy the aluminum brake mount(will save you some money on spur gears and brake better), make a brace for the upper a arms like the one for the lower arms, bigger cooling head, failsafe.

Sorry mate, I dont agree with you there, they are definately weak spots.

What do YOU think makes them weak then?

The stock motor or even one that has the .18 conversion in it does not need the bigger cooling head.
The bigger cooling head over cools the motor and leads to tuning issues, and the cvd's and the diff cups are definitely weak spots.
I had some pretty bad crashes with my truck and have never broken an axle there.

Other than that very sound advise about the locktite, failsafe and brake seat.



rolland

IMHO the design of them makes them weak, for one you can see whats left when a diff cup breaks and you can see exactly how much metal was actually holding it together (NOT MUCH!!) the slot they machine into it weakens it too much as there is not enough metal down the bottom end of the slot.
And with the CVD's its the same story when they break right up by the universal, again take a look at exactly how much metal was actually holding it together, with the CVD the slot they machine into it on the ball part actually weakens it substantially as the slot pertrudes all the way into the main shaft.
As for them twisting and breaking (at the dogbone end) this is caused by them being too weak because of: a. the materials used or b. the overall thickness of the shaft (although the thickness can be overcome if the material used is stronger).

As well as this you have the company admitting they are weak! What more do you need!!!

gotta throw my 2 pence in then...

should mention first that all my experience of cen shafts and cups, bar a couple of tanks on the mt, is based on the rally setup.

the os 18 is the biggest bug for my shafts - they werent designed for the 18 so thats fair enough, but a bit of a shame. fact is tho that the cen shafts (cept for rollands - hes dead lucky) seem to break more often than other trucks do. flame suit is on... all of mine broke where the hex pin goes thru, either thru an accident or on acceleration on reasonably high grip surfaces.

regards to the cups, im guessing that most are broken due to the suspension being a little too high as standard which results in the bone part binding in the cup, so something has to give - better a cup than a shaft. sorted with a bit of fuel line or similar in the shock to lower the hieght, makes it handle better too on smoother surfaces. also fuel line or o rings in the cups helps somewhat. the diff cup mod works well for me, but only addresses the cups, my shafts were still a problem.

to give an example - my plastic tmaxx shafts on my funfactor mt have lasted over a gallon now with a sh28 behind them. braking actually has done more damage to them than the engine... i ran the truck for maybe 2 tanks in the mt setup with the cen shafts before one broke. again it was at the hex pin hole, admittedly that was with tmaxx wheels, but thats how i wanted it to be.

wassat... 6p and counting?

overall i feel its the upgraded engines that are causing more issues than any other, with the exception of the diff cups and thats something that can be made a bit more tolerable with the above mentioned stuff.

8p... hope that kinda helps.

lol edit: so yea - its the design of the shafts for certain, they are too thin or of too low a grade of material to withstand a reasonable amount of hammer with that hex pin hole thru it... imo...