Doing timing on a 1995 LS400. How worried to be about hairline cracks in rubber layer of harmonic balancer?

 

That's normal for the age in fact that balancer is in excellent condition. Spray the rubber areas down with 303 Protectant wait a day then clean off the friction surfaces. Does it help? Maybe not but it might. I also soak drive belts in 303 for a day. Don't do this to a timing belt, it might be fine or not I have not tested this scenario.

Look for wear marks on the lower timing cover this will tell you if the pulley is wobbling. I recommend sourcing a spare balancer if you plan on keeping the car indefinitely eventually they do go bad.

 

Ok thank you. There’s a parts sale happening at Lexus right now so I am tempted to just replace while I have everything apart as I hope to not be doing timing again on this car. Very good to know though it’s not the worst you’ve seen.

Edit: I do realize now replacing just the harmonic balancer in the future doesn’t require a full tear down it seems. So that’s nice.

 

Yep no need to tear into the timing belt components.

 

as stated it looks great for the age, i would run it w/o hesitation! surface cracks are normal.

 

Thank you both

 

Just chiming in here. I replaced mine earlier this year, which looked almost identical to yours

My original balancer is probably still fine, and I didn't find any looseness in the part or notice any vibration in my accessory belt. However, I'm keeping the original balancer as a spare part in case I ever need to re-use or rebuild it in the future.

 

How great of a deal are they offering you? If they are clearing out old stock for pennies and that’s about the only thing that they had for your car then you might as well, and no reason to wait to install it, might as well put it on right away. But if they’re offering like 10%off of a $300 part then there is definitely plenty of other possible problems you should consider doing first. Harmonic Balancers rarely fail, especially on a 1UZ, which is why they have had it in stock for over 25 years.

 

Sounds good thanks. Yeah, I am kind of the same, and I like the peace of mind.

 

It’s just the normal periodic online Lexus parts sale. Apparently this part now is a $537 MSRP. Yikes. With the dealer specific discount (Bell Lexus North Scottsdale) and the periodic sale discount I paid $323 incl shipping. So definitely not a “steal” or anything close to it but I know if OEM I will never have to touch again. Note that the latest part is cross compatible with GS430, SC430, LS430 according to the Lexus website, so I’m slightly hopeful that means the inventory is a little fresher than those 1UZ only parts that can collect dust. I’m torn halfway between buttoning up timing job with existing one and keeping this one in my personal “stock” of new uninstalled parts vs just installing it right away while I have stuff apart.

 

They do fail, ALOT. I had one that looked like that one and that was the cause of a very bad engine shake under load. I was lucky to change it before complete failure. Some people don't change 'em cuz of the $4-$500 price tag. (so they're in stock for over 25 years) I forget which brand I used but it was aftermarket, and still good...But I hardly drive it anymore.
If you do end up buying one with the discount, put it on, don't just put it in your "stock" pile. Cuz when it does fail it will take out other parts along with it.
Here's one I remember that failed from a few years ago:
https://www.clublexus.com/forums/ls-...-misalign.html

 

Noted and thank you. I’m gonna put the new one on I think as to your point, it does look like failure can happen suddenly and can be ugly when it does. I just wanted to button up after my timing job and make sure I hadn’t trashed my engine. I had a cam roll on me and it took my breath away. However, startup and idle is very smooth. I may pay someone with a lift to torque the new one to spec. I was able to torque the cam bolts to spec but this harmonic balancer bolt I know needs to go to 180 pound feet.