Harmonic Balancer ?

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Bright Idea

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I am going to be replacing the radiator and water pump on my 90 suburban 350 TBI. While looking things over I noticed the rubber ring on the Harmonic Balancer looks deteriorated in a couple of spots. Does this indicate it is time to replace ? If so, it appears this would be the time to do it ? Anything I should know about taking this repair on ? Thanks in advance for you replies.
 

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It's probably ok as it is. Pictures would help judge that though.

You are right though, it's much easier with the radiator and water pump out. You will just need a proper tool to remove and install the balancer. They can be 'rented' from some of the parts store chains.
 

ali_c20

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I would change it, even if it's ok now you don't know how long it will hold up as it shows sign of wear on the rubber. It's not much work to change the balancer. As you are removing the water pump and radiator it's a good moment to do all this in one run. Check the front main seal (or get a new one to be safe) and the timing cover.
 

1987 GMC Jimmy

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Does it spin true? I’ve seen some with dry rotted rubber that I would never run, and in my experience, the rubber was cracking and poking outward in places. It also wasn’t spinning true. I replaced mine at the same time as water pump, and I got a leak fixed in the radiator. It’s convenient to go that route for sure.
 

Bright Idea

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looks to be spinning true but after looking at it a bit closer there is an area of the protruding rubber ring that is actually gone. it really looks to be original and inevitably if I dont change it i will wish I had and failure could cause some collateral damage "its just time and money"
 

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I'd personally have to disagree. I've seen many that look deteriorated on the outside, but that rubber goes all the way through so just because it appears bad where it's been exposed to weather, doesn't mean it's bad. I'd just check it, if it hasn't slipped and the timing mark is in the correct place and if so, send it. Leave it alone.

Now isn't the time to consider that being replaced anyway if all your doing is a water pump and radiator. No reason to disturb it. If it ain't broke, don't fix it. Now if you were doing a timing chain? Different story. It might be time to give it a thorough looking over and possibly replacing it. Don't create more work and expense for yourself.

If you want to do something just for ***** and giggles while the cooling system is drained. Be sure to replace your thermostat. It's cheap and easy to get to. Also check over your radiator and heater hoses. Now would be the time to replace any of that if it's marginal.
 

Bright Idea

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Thanks for the different opinions. Yes, hoses and thermostat will be replaced. There are at least 3 different thermostat temps available. 165,180 and 195 and I think the 180 may be the stock. Any reason to consider running a 195 ? We do not have much hot weather here and the suburban is a big box to warm up.
 

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Thanks for the different opinions. Yes, hoses and thermostat will be replaced. There are at least 3 different thermostat temps available. 165,180 and 195 and I think the 180 may be the stock. Any reason to consider running a 195 ? We do not have much hot weather here and the suburban is a big box to warm up.
Being that it's a 1990 and TBI, I'd run the 195. If it were non computer controlled, I'd run the 180. But the computer systems like the 195 better and some of them won't even go into full closed loop operation until over 180 degrees. If you don't get it hot enough, it'll stay in open loop and not tune the truck right as if it's cold and run rich and hurt your mpg and all that ****.
 

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I wouldn't be concerned, but if you want to replace it include a new seal. You can buy a cheap china made puller, won't set you back much at all.
You might consider handling the china made puller with rubber gloves, that get disposed of in a fire afterwards. Disinfect the tool asap!
 

Bright Idea

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After some more inspection The rubber on the back side is fully intact. The frontside has two areas where the protruding rubber is a bit tattered.it appears to be running true and feels solid when working it by hand. I am unable to feel any movement. Going to leave well enough alone at this point. Thanks for all of the replies.
 

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