4JB1T Harmonic Balancer Pulley

[kg4pam]

Good day- I've noticed an issue with my engine that I hoped some of you good folks might be able to shed some light on. I am in the US, and have a 4JB1T in a Jeep CJ-7. I noticed a rattling sound coming from the front of the engine. Most of the issues stemmed from a bad bearing in the Chinese water pump I have on there. However, I also noticed that the v-belt accessory drive pulley appeared to be loose. I remove the 4 bolts and pulled the pulley off the crank. The center bolt on the crank appears to be tight, however the spacer behind it seems to be loose. (red arrow in image)

The 'toothed' timing belt pulley seems to be tight, but the spacer that the v-belt pulley bolts to has probably ~1-2mm of rotational play. Like a keyway or something is worn...

Question- What would cause this to loosen, and would there be any harm in removing the main bolt and putting a shim behind it to stop the pulley spacer from moving (yellow line in image)? I realize this would probably mean setting the timing, or at least putting the bolts in place to prevent timing from changing while i work on it.

I read some other posts alluding to a harmonic balancer 'slipping' causing the timing marks to be off, but I think what I have here is a separate issue.

Or should I just leave it be and not worry about it?

Thank you very much!!

[pig75]

Try here it might help http://www.clubisuzu.com/viewtopic.php? ... 713fe2e734
http://www.clubisuzu.com/viewtopic.php? ... f84ab4df37

[geeves]

Yes there is a keyway in there. The big bolt should have 150 ft pound torque but if the keyway is damaged you may have a problem. The spacer can be purchased new but not cheap and dont know where in USA. however they sometimes cause wear in the crank which makes it a big job.
An engine machinist might be able to repair both but otherwise its a new crank ands spacer

[kg4pam]

Thank you both for the info. So will there be any harm in pulling the center bolt to inspect the spacer/crank? I assume the timing belt pulley (sprocket rather) is also keyed on the crank?

Also- It won't let me see the photos that were attached. I assume this is due to my low post count. Is there any way around that?

Thanks!!!

[geeves]

your photo is there so you should be able to see it. From memory the cambelt pulley is bolted to the spacer which has the keyway.

[kg4pam]

Ok, I made a tool that bolts to the 4 smaller holts to hold the crank. I tried loosening the large middle bolt. It started moving a bit, but never got really easier like it was breaking loose. I was worried about stripping it or twisting it off, so I stopped. I then tried tightening back down. It tightened a bit, but the spacer is still loose. Question for you all- how likely am I to strip the bolt with a standard sized 1/2" ratchet (no cheater bars or anything like that)? Should I keep trying to loosen it? I don't want to wring it off and then have to drill out the bolt in the end of the crank... I actually lucked out and procured a spare engine last week (A very rare feat for this engine here in the States!). I may just drive the one with the loose pulley as-is while I overhaul and clean the 'new' engine, so long as I won't totally ruin it if I do.

[geeves]

If you loose the keyway the injector pump and valves will be out of line. Valve hitting piston will at best stop you suddenly. At worst new engine. If you snap the bolt its an engine out repair and if the crank has already worn it will be a new crank