I have a traxxas 3.3 & the crankshaft is moving in and out about 1/8". It leaks air by there too. I was just wondering if anyone else has ever had this problem? I have a new crankcase with new bearings I didn't know if it would be better to replace the cranshaft with the new case? Or if it could be a piston rod issue? Thanks for any help.
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Crankshaft moving in and out.
- Thread starter bplakers
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2revo1maxx
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Sounds like the starter shaft is missing.
Phins Fan
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either missing or worn out. I've never had any slop from my crankshaft.
Ballen
RCTalk Addict
maybe has bad bearings ?
2revo1maxx
Hardcore RCTalk User
Warm the block then push it out.
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- #8
what did you use to push it out with? I had it warmed up with hair dryer.
It ended up being a bad piston & inner bearing was bad. I might have broke the piston trying to push the sleeve out though idk. There was just a few pieces that broke off where the notch is in piston. Looks like I'm going to have a whole new motor. What I should of done months ago.
It ended up being a bad piston & inner bearing was bad. I might have broke the piston trying to push the sleeve out though idk. There was just a few pieces that broke off where the notch is in piston. Looks like I'm going to have a whole new motor. What I should of done months ago.
2revo1maxx
Hardcore RCTalk User
They can be stuck in there pretty good! I use a plastic (uhmw) dowel....maybe 1/4 inch or so?
Snook Man
Hardcore RCTalk User
The easiest way to remove a sleeve is to insert 1 or 2 zip ties through the exhaust port into the cylinder when the piston is at BDC, then turn the flywheel. In a perfect world the piston will catch the zip tie and push the sleeve up far enough for removal.
Often (in our not so perfect world) the sleeve is tight and the piston will cut through the zip tie(s), heating the block will then help expand it and make it easier to push the sleeve up. If 2 zip ties and heat still won’t budge the sleeve after a few attempts it is not a good idea to use any type of dowel to push the sleeve up through the backplate opening as the sleeve will most often be damaged.
A good soak in penetrating oil overnight will then usually free it up enough for the zip ties and heat to work.
Often (in our not so perfect world) the sleeve is tight and the piston will cut through the zip tie(s), heating the block will then help expand it and make it easier to push the sleeve up. If 2 zip ties and heat still won’t budge the sleeve after a few attempts it is not a good idea to use any type of dowel to push the sleeve up through the backplate opening as the sleeve will most often be damaged.
A good soak in penetrating oil overnight will then usually free it up enough for the zip ties and heat to work.
2revo1maxx
Hardcore RCTalk User
An ultra high molecular weight plastic dowel is not going to hurt anything.
Snook Man
Hardcore RCTalk User
You misinterpreted the meaning of my post.
If the sleeve is stuck enough that a couple of zip ties and heat will not get it to slide up after a few attempts, you will not be able to simply push it up by hand with any type of dowel from the bottom without resorting to tapping the dowel with a hammer/mallet or pressure of some sort.
If the dowel is dense enough to transfer the energy of the impact/pressure to the sleeve and push it up (whether it is made from an ultra high molecular weight plastic or a spaghetti noodle really makes no difference) the bottom of the sleeve will often become flared slightly where the dowel makes contact. This will cause the sleeve to stay tight/bind on its way up the block. Most will then grab the top lip with a pair of pliers and twist and turn the sleeve out with significant force. Just a little too much clamping force with the pliers can distort/egg/oval the top of the sleeve in the pinch zone making what may have been a usable sleeve a virtual paper weight.
If you can push the sleeve up with a dowel by hand with reasonable force all is well, 1 zip tie will usually do the trick also in that instance.
The OP had already tried an old tooth brush and had no successes and that was the reason for my post. It was Not to say not to use a dowel…
If the sleeve is stuck enough that a couple of zip ties and heat will not get it to slide up after a few attempts, you will not be able to simply push it up by hand with any type of dowel from the bottom without resorting to tapping the dowel with a hammer/mallet or pressure of some sort.
If the dowel is dense enough to transfer the energy of the impact/pressure to the sleeve and push it up (whether it is made from an ultra high molecular weight plastic or a spaghetti noodle really makes no difference) the bottom of the sleeve will often become flared slightly where the dowel makes contact. This will cause the sleeve to stay tight/bind on its way up the block. Most will then grab the top lip with a pair of pliers and twist and turn the sleeve out with significant force. Just a little too much clamping force with the pliers can distort/egg/oval the top of the sleeve in the pinch zone making what may have been a usable sleeve a virtual paper weight.
If you can push the sleeve up with a dowel by hand with reasonable force all is well, 1 zip tie will usually do the trick also in that instance.
The OP had already tried an old tooth brush and had no successes and that was the reason for my post. It was Not to say not to use a dowel…
ohsnap
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I think Snook Man is pretty spot on in his step by step process - and I do reserve the use of a dowel.
By that time though, I've already written off the current cylinder and piston.
I think bplakers is there - if not wondering about replacing the whole engine.
bp - Sounds like you need the cylinder, piston, and conrod etc, and bearings.
I would also check the part of the crankshaft that the conrod rides on - is it still round or has it been deformed? You need calipers.
It sounds to me that you're kind of at a point where it's about the same to replace the engine as is is to rebuild it.
Rebuilding is fun, and it teaches you how to work on your engine and how it works, but it's not always the most cost efficient route.
By that time though, I've already written off the current cylinder and piston.
I think bplakers is there - if not wondering about replacing the whole engine.
bp - Sounds like you need the cylinder, piston, and conrod etc, and bearings.
I would also check the part of the crankshaft that the conrod rides on - is it still round or has it been deformed? You need calipers.
It sounds to me that you're kind of at a point where it's about the same to replace the engine as is is to rebuild it.
Rebuilding is fun, and it teaches you how to work on your engine and how it works, but it's not always the most cost efficient route.
Last edited:
- Thread starter
- #15
Yeah I have ordered everything. With the other upgrades I was going to make for it before have $300 sunk into it. Thinking of just ordering a new tranny & shafts so just about everything is new. I bought it used never really ran right since I've had it. That or I'll get this one running and in a week or two order me a savage 5.9.
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