FiReD-uP

Ok ill start from the begining. i changed out my shock oil to somthing a little more heavy 30 wt works beautifuly. but while i was out playing around on our gravel drive way the rear lost power. now when i pick the truck up the rear wheels spin just as much as the front but while its on the ground it dosnt spin them at all it looses all power. so i check out my bevel gear and there was no damage so i took my diff out. one of the screws was loose so i opened up the diff and there is no missing teeth nothing. the paper gasket in the diff was torn so i replaced it with an hpi replacement part. but i still have the problem ? any suggestions?[:@][:@][:@]

vizaracer

check the screws that hold the drive cups. bet thats your problem. it could have to much pressure on them to spin with it on the ground without pins and they are suppose to have pins but with the truck in the air, there is no friction to make it just spin. if you understand what im trying to say.

FiReD-uP

your talking about the 4 flat headed screws that hold the gear to the cup right?

vizaracer

no, i am talking about the drive cups. the dogbones are inbetween them. heres a pic of a drive cup. they take a screw in the side.

FiReD-uP

sweet ill check it out and let everyone know whats up for some stupid reason i didnt even think of that.
thank god for the forums!

FiReD-uP

well i checked out the drive cups and the pins are still there.
the diff seems to be working. im not sure what is going on.
anyway i can trouble shoot this to find out what the problem is?

vizaracer

did you check the one at the tranny also? theres one at the tranny and one at the diff. and then check the dogbone for wear on the little post things that come out on each side.

vizaracer

oh, if your truck is stopping, the one at the tranny is working fine and the pin is there.

vizaracer

are your wheels stripped?? to check that, take off the wheels and check the hex hubs. also check to see if the tire is loose and off the rim. the rim would only spin then and the tire would stay in place.

FiReD-uP

once again Viz comes through

the tires werent stripped but,
the pin in the center (tranny cup)
was gone!
time to get a new one and check all my other pins! thank you!

vizaracer

i locktight mine. never lost one either. thats how you prevent the problem.

FiReD-uP

ok so i got a new screw to replace the one i thought i had lost. ( it wasnt lost it was just screwed way into there.)| so i ran the truck (bored) and while im on the gas with the trucks rear wheels on the ground the dont spin (the front tires are spinning like mad) [:@] but the CR axel does. what the heck is wrong!

vizaracer

check the dogbone to see if the little things on the end work and if they spin. to help diagnose the problem, get the truck running and lift it in air and let the tires move, then look at the bottom and see if the dogbone is spinning. if it is, then there can be a problem that is after the the center rear dogbone. if it doesnt spin, the problem is before the dogbone.

RC Monster Man

Have you figured your problem out?

RC Monster Man

Just wondering if you found your problem?

FiReD-uP

nope the Center rear spins freely

FiReD-uP

still having problems

vizaracer

it doesnt make sense. it has to be a worn gear or something. oh, got a possible solution. since you took apart the diff, you maybe missing pins that go under the 2 bevel gears in it. they are the bigger gears that are in the diff. also, do you have any worn drive cups that the dogbones may be slipping on??

FiReD-uP

ill have to tear apart the truck tonight.
ill let you know asap
thanks for all the help in advace

vizaracer

before you do that, if you havent started yet, let the wheels move in the air how they do while looking at the bottom of the truck, then i want you to stop the real wheels by putting pressure on they and see if the dogbone is still spinning or not. and lave the truck still giving throttle so we know if the dogbone has power in it by the front spinning. that would let us know that the problem is behind the dogbone or is near the tranny. but it should be behind it im assuming.

FiReD-uP

yeah viz i tried it yesterday the rear center dog is spinning like mad and the tires (rear that i am holding) take almost no pressure to hold. none actually its like the diff is too loose or somthing.

vizaracer

do the outer dogbones turn when you did that?? those are the ones going to the tires from the diff. im just doing a process of elimination. if they do not spin, its in the diff.

FiReD-uP

tore apart my diff again and found that the diff cup is totaly shredded inside [sm=bananahead.gif] couldnt see it before beacuse of the black grease. could be that i shredded it more when i was trying to find the problem after i put it back togeather the first time. anywas im going to put it back togeather with a new diff cup and see if it fixed the problem!

vizaracer

that should fix it. i got my front end apart right now, i wrecked[:@]. look at this thing

FiReD-uP

Now it pulls like a train again1!!! yay
viz? did you bend your shock shaft?
i know you broke you bumper mount that sucks just fixed mine.