Please help Im in a huge debate>>>
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From: Houston (The Champions)
Please help Im in a huge debate>>> Ive been working on LS motors since they first came out. Ive installed many many many crank pulleys and the way Ive done it was to genlty tap the crank pulley on then use the old bolt to "pre seat" the pulley by torquing the bolt to 200 ft lbs. then I remove that bolt and install a new bolt then torque it to 249 ft lbs. Ive done this many times with no issues EVER. Now Im in a debate with a guy that Im not doing it right. He said that the pulley isnt on enough and the bolt needs to go on another 140 degrees. Ok, I can see that, but my question to you guys is, whats the purpose of that 140 degrees.? I believe its to set the bolt, but this guy is telling me that it actually pushes the pulley on more. I dont believe him. PLEASE HELP GUYS..
GM says:
Crankshaft Balancer Bolt
Installation Pass to Ensure the Balancer is Completely Installed 330 Nm (240 ft. lbs.) Using old bolt.
First Pass Install a NEW Bolt After the Installation Pass and Tighten as Described in the First and Final Passes 50 Nm (37 ft. lbs.)
Final Pass 140 degrees
So I would say that your 249 ft lbs. is a substitute for GM's 37 foot pounds + 140 degrees. Whether the two are "identical" I can't say.
Crankshaft Balancer Bolt
Installation Pass to Ensure the Balancer is Completely Installed 330 Nm (240 ft. lbs.) Using old bolt.
First Pass Install a NEW Bolt After the Installation Pass and Tighten as Described in the First and Final Passes 50 Nm (37 ft. lbs.)
Final Pass 140 degrees
So I would say that your 249 ft lbs. is a substitute for GM's 37 foot pounds + 140 degrees. Whether the two are "identical" I can't say.
Huge debate....lol. Darkman is correct and you and you're friend are both wrong. The last step that describes turning the bolt a set amount of degrees is to stretch the new bolt, not to seat the pulley anymore.
Also, using an old bolt to pull the pulley on is a bad idea and can strip the threads in the crank. Using a threaded rod to make sure you are grabbing as many thread as as possible is smarter.
Also, using an old bolt to pull the pulley on is a bad idea and can strip the threads in the crank. Using a threaded rod to make sure you are grabbing as many thread as as possible is smarter.
Ive been working on LS motors since they first came out. Ive installed many many many crank pulleys and the way Ive done it was to genlty tap the crank pulley on then use the old bolt to "pre seat" the pulley by torquing the bolt to 200 ft lbs. then I remove that bolt and install a new bolt then torque it to 249 ft lbs. Ive done this many times with no issues EVER. Now Im in a debate with a guy that Im not doing it right. He said that the pulley isnt on enough and the bolt needs to go on another 140 degrees. Ok, I can see that, but my question to you guys is, whats the purpose of that 140 degrees.? I believe its to set the bolt, but this guy is telling me that it actually pushes the pulley on more. I dont believe him. PLEASE HELP GUYS..
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From: Houston (The Champions)
Well, I guess I deserve that. I didnt explain my method completely. I heat the balancer in the oven for a bit and then install it. It literally slides on. And when I say I "tapped" it on I meant a real slight tap. Its just a bit harder then tapping with my fist. And When I use the old bolt to "pre-seat" the balancer, I make sure that I have AT LEAST 5 or 6 threads before I start to tighten down on it. I know that if you try and do this with only 1 or 2 threads then you would pull the first couple of threads out of the crank.
