Crank pulley bolt won't stay tight

[1steclipse]

was wondering if anybody could help me. i have a 420a eclipse and the bolt that connects the pulley to the crankshaft keeps backing out. i have torqued to the right specification in my book. im wondering if its just not tight enough or if there is something else i need. im afraid to tighting it anymore i dont want to strip the bolt or crankshaft. is ther something im missing. or maybe somebody knows of a torque specification i dont. ive read about these things being warped could that be the problem any feedback would be appreciated

 

[95TalonOwner]

One of my guesses is maybe it's not the stock bolt and it's too long and your bottoming out the bolt slightly which would cause it to torque down but not actually tighten the pulley. I don't know thats just one suggestion. Another one would be get a new bolt or possibly a new pulley or use some thread lock.

Is it the stock pulley that is on the motor?

 

[1steclipse]

thanks for the reply but it is the stock bolt from my original engine but it is a used pulley. i just put in a rebuilt stock engine and it was all fine for a while then one day my steering wheel wouldnt move so i looked, and the pulley was just hangin there witht the bolt. so i torqued it again, and once again it rode for a while, then the same thing happened. i m probably going to get a new harmonic balancer and bolt and see if that makes a difference. i just wanted to see if there was some kind of trick i was missing.

 

[dsmdragon]

Dude all you need to do is Go buy some lock tight and tighten it down. no matter what you are doing if it has a lot of routing force on it it should be torqued down with blue lock-tight. Then you can start freaken if that don't help because that bolt isn't cheep from the dealer

 

[VelocitàPaola]

How sure are you that you're torquing it to the proper spec? It should be torqued to 105ft/lbs. That's some serious torque. Most torque wrenches that I've seen don't go past 80ft/lbs, so make sure you're tightening it enough.

What I did was use a torque wrench to tighten it to 80ft/lbs, then use a breaker bar on my 1/2" ratchet to turn it another 1/4 turn or so. Also, the bolt comes with a threadlocker on it from the factory. Try using some Loc-Tite or something.

That's a pretty hefty bolt, so don't worry about it stripping too much. The number one reason for it backing out is improper torque.

 

[cimotorsports]

weve actually seen a bolt that kept coming loose because the pulley itself wasnt installed on the entire way ,and when the bolt was tighted to spec it would actually do no good because the pulley would slowly move inwards from vibration and tension from the belts ... just a suggestion since they are a pretty tight fit sometimes, i would check just to be sure

 

[1steclipse]

i torqued it to whatever the chilton eclipse book said. cant remember what the book said right now though id have to look. it seems to me it wasnt that high though (105). ill try that with the lock tight and see if it works. i just wanted to hear i wouldnt strip the damn thing. thanks guys for the help much appreciated

 

[bryanwheat]

I always ise an impact gun on those, it is also good sometimes to use a lead hammer, and beat the ballancer flush into the crankshaft. You will know when it is in place because it won't go any further. Than tighten it with an impact with a little loctite on the bolt. IF you are torqing it, and it is coming loose, if has to be that it isn't on the crank all the way, and you are just tightening it up to the balancer, but not the crank.

 

[Locke]

if you use an impact on that, turn the pressure down.

 

[dr1665]

I can't say I've ever used Loc-Tite on that bolt on my car and that bolt has been in and out three or four dozen times in the last three years. You pound the pulley on and then you lock that bolt down to 105ft-lbs like Paul said. It ain't goin' nowhere. Look at it! Where you goin'? Nowhere!

TIP:
If you can while you have the pulley off, cut a window in the timing belt cover over the area where the lower timing mark is located on the oil pump. (Recommended when the cover is off, of coruse.) Then crank the motor over by hand and line up the lower marks. Slide your pulley back onto the crank so that one of the holes/windows in it lines up with the marks.

Since the pulley hole will be indexed to the mark on the crank sprocket, now, and there is a window into the mark on the oil pan, you will be able to remove the splash guard and check your timing inside all of five minutes in the future.

Something I did that I have loved having done. Thought I would share.