I plan on re-installing my hub and balancer this weekend. I noticed that the hub is not keyed, but does have an arrow that is suppose to be at 12 o'clock at TDC. Are there any tricks to getting the hub on, or do I just ease it on by tightening the bolt down? Is it ok to use oil on the crank to help it slide on? Since it is not keyed, what prevents the hub from slipping?

Thanks,
Chris - 1996 LT4

 

Chris,
It is a tolerance fit. I used scotchbrite to polish the crankshaft snout, then used the bolt to mechanically pull the balancer hub into position. In my opinion, I don't think I would use oil. If you want to lubricate it a little, I would use anti-sieze or dielectric grease ~ before anything else.

You are correct that it is not keyed. It is best to align the pulley and hub as you have indicated ~ however, I have talked to quite a few guys who have just slapped it on and have never had any vibration problems as a result.

Good Luck,
~ Purp

 

I wouldn't use the bolt to pull it on. Big problem if you damage the crank threads. Use an installer or make one - get a grade 8 bolt, nut and thick washer. Run the nut up on the bolt, put the washer on then thread the bolt into the crank - hand tight only. Tighten the nut to seat the hub. When seated, the bolt can be removed by hand - no danger of stripping the threads.

Great suggestion about cleaning everything up first.

 

I was worried aobu that when I changed out my opti a couple years back... But I gave it a try anyway and was amazed at how easy the bolt pulled the dampener back on... That thing was a bear to pull off, but it slid on very easily when using the bolt to pull it back on the crank... I used one hand on a short ratchet so I know I wasn't putting very much pressure at all on the bolt/threads... The part I was most concerned about was when I was starting the bolt making sure I didn't pull out the threads trying to get the bolt to catch...

Worked out well though... An installer is the ideal way to go but before buying one, I'd give this method a try first... You can feel what's going on so you should be able to tell if it's going to go without much effort or not...

 

I agree. My friend and I stripped the threads on the crank pulling the balancer in on his 454 Chevy V8 in his C3 vette a few years ago doing what was suggested. He had to buy an $85 helicoil tap and a large bit to fix it.

A threaded rod and bolt can be used can also be used to pull the balancer on. Lubricate the rod threads well. I'd use antisieze on the crank snout.

 

I did what AquaMetallic94LT1 did. Use a threaded rod or really long bolt and use it as an installer.

I would not use a bolt to pull the snout on. Lots of stress directly on the threads then and you definitely don't want to strip that bolt!

:)

 

Thanks guys, I'm glad I asked. I will go with the suggested home-made installer procedure.

Chris - 1996 LT4

 

You can have the hub machined for a keyway, the crank has the slot ready to accept a key. When I replaced mine recently I had this done. It cost me 65$ if I remember correctly to have the keyway machined into the hub. There is a machine shop in Mesa I can recommend if you are interested in having it done.

 

Explain to me how using a threaded rod vs. the original bolt puts less stress on the crankshaft threads.

olephart ~ notice that I have asked this in a kinder /gentler way :yesnod:

Having built SBC engines for close to 35 years now, I have never came close to messing up the threads inside the crankshaft or on the threaded bolt crank bolt. I have found that the LT1/LT4 balancer hub is difficult to remove at times, but always slides back into place with nominal pressure when using a standard 1/2" ratchet and socket.

:confused: ~ Purp

Actually guys, I happen to agree with any way that mechanically pulls the balancer on. I cringe when I see people hammer them on with the side of a small sledge! :eek:


[Modified by PurpleC4, 10:39 AM 6/14/2002]

 

IF YOU REFER TO THE gm MANUAL..it says to use an installer.. the installer is what looks like a piece of pipe the fits over the snout of the Hub and is driven onto the crank.. i use the installer plus the threaded stude to install.. major "Whacking" is not used, but with the installer over the hub, a block of wood to slip between the crossmember and the steering rack, then double check your in the correct position, and with solid control movements tap the wood.. generally 10 taps and then check the pressure on the Nut, do this until no more pressure is relieved from the Nut from bottoming out, and then i check the measurement of the forward most point of the hub to the prior measure point on the block to ensure the hub has returned to its properly seated seated position.. DO NOT:

-grab the biggest hammer and start smacking around in the engine Bay.. mind you controled solid TAPS!! hope this helps.. I have seen two stripped crank snouts to date.. the bolt is not the correct tool to use.. the crank internal threads should remain motionless along with the installing stud while the lubricate threads of the stud are used to pull the hub with a Nuts and a few washers. using the bolt will degredate its torque stretch integrity and compromise the integrity of the crank threads. hope this helps!

Best Regards,
Chris

 

Well you definitely have more experience than I...

I know when I reinstalled my hub, it went on pretty dang tight.

My feeling is if you run a threaded rod into the crank threads (lightly bottomed) and then use a large washer and nut to push the hub on. This seems to me that all the 'friction' or whatever is on that single nut pushing the washer and hub rather than on the crank snout threads. I even went so far as to put a double nut further out on the rod to hold the rod from threading in more or turning (held with another wrench).

:)