"When you know stuff you can do stuff!" or How to fix a Jeep

[KA4D]

Some members of the WPBARG may recall that my Jeep was out of commission for a bit because of the harmonic balancer.

It started with a squeak that was obviously related to the serpentine belt. I grew up knowing these as fan belts because they (primarily) drove the cooling fan, but these days they drive everything - fan, water pump, alternator, power steering pump and air conditioning compressor. I tried identifying the source of the squeak, but it eluded me until one evening back in February.

Were just a few hundreds yards from home when there was a loud CLANK! followed shortly thereafter by another loud CLANK! I decided to turn around at the next side street, but discovered that my power steering was not working. Then a "CHECK GAUGES" light lit up - a first for me and this Jeep. A glance at the gauges revealed that the voltage was dropping.

My first thought was that no power steering + low voltage = fan belt.

Being so close to home, we made it back safely and discovered that yes, the belt had slipped off the pulleys. The fan seemed to be rubbing against the pulley at the bottom - the one connected to the crankshaft. My first impression was that the fan had somehow slipped. It's attached to the water pump, so I started researching how to replace it.

You might be thinking what my wife actually said, "Why not just get a mechanic?" Well, mechanics are now going for $100-$200/hour and I've worked on cars, boats and engines on and off since high school. It's really just a matter of unbolting the part and attaching a new one. You just need to know the tools and steps involved. I had most of the tools, the factory service manual (FSM), YouTube, and a few Jeep-related bulletin boards.

It was on one of the bulletin boards that my focus shifted from the water pump to the harmonic balancer - the pulley at the bottom which is connected to the crankshaft. Also known as a flywheel, it's a two piece unit, with an inner and outer ring secured together with a rubber gasket. If the gasket fails, the pieces can separate - horizontally. A second look revealed this to be the case. The outer ring had shifted forward, coming in contact with the fan (the CLANK!). The fanbelt had been squeaking - and probably jumped off - because of the increasing angle between the plane of the other pulleys and the balancer.

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Removing and replacing the balancer required removing the radiator (which required draining said radiator). That was easy enough. Removing the nut on the balancer required a little leverage gained by a few bolts and a wrench to hold it steady, and a pipe to extend the length of the ratchet. This was followed with a dedicated puller tool (not shown).

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Behind the balancer is the front main seal. Since I was already there, and I'm a believer in preventative maintenance, I decided to replace that as well. That's when things went sideways. The seal sits on a lip in the face of the timing chain cover. A gasket puller is used to remove it. When I positioned the puller, I wasn't paying attention, and caught the lip of the cover. The gasket came out, but so did a chip at the lower left of lip.

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Now I needed a new timing chain cover. This delayed repair for a week while a new (used) part arrived from a junk yard in Indiana. I opted against the locally available aftermarket parts because the reviews warned of a poor fit.

While everything was out, I replaced the steering damper because it was leaking.

Unfortunately, I missed February's Saturday in the Park because that was the day I had everything on hand. I replaced the timing chain cover, gaskets, front main seal, balancer, belt and a rusted hose clamp, reinstalled the radiator and fan, and added coolant and oil (the latter had to be drained because of the timing chain cover).

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The engine came to life without leaks. As Pete Juliano, N6QW, said, "When you know stuff you can do stuff!"

[Michael M]

I remember power steering pumps all too well. Today, it's all about fuel economy, so most cars now use electric power steering. I wouldn't consider that a downside, but there's a lot of problems with today's engines because of that drive for fuel economy, not the least of which is long-term reliability. I'm guessing that's a timing chain and not a belt, otherwise I imagine you would have replaced that as well. Back in the day I would usually do the water pump while I was in there. Looks like you had a fair amount of room, which is nice!

Great job. Let me know your hours!

I imagine you misspoke, but just for clarity, the harmonic balancer is different from the flywheel… they're at opposite ends of the crank.

[KA4D]

I imagine you misspoke, but just for clarity, the harmonic balancer is different from the flywheel… they're at opposite ends of the crank.

You are correct; I'm not sure why I thought of this as the flywheel, although it does have another name. The FSM uses "vibration damper" and "vibration damper pulley" interchangeably. However, everyone else (including the parts suppliers) refers to it as a harmonic balancer.

I'm guessing that's a timing chain and not a belt, otherwise I imagine you would have replaced that as well.

The belt seen in the pic is an accessory belt (and I did replace it); the timing chain is actually a chain. I left that alone lest I drown in scope creep. Here it is without the aforementioned cover in place:

TimingChain.jpg

Looks like you had a fair amount of room, which is nice!

Only because I removed the radiator

Radiator.jpg

[Michael M]

Somehow I missed your response. Anyway, great project! Back in the day, we always refered to that as a harmonic balancer. Maybe the parts guys are old like me.