Help with harmonic balancer

I joined today so I can post pictures. I've received a lot of great help on this forum and really appreciate it.

I've been working on replacing the radiator, water pump, harmonic balancer and alternator. I have the water pump and alternator installed and am working on the HB.

I finally got the old balancer out. For those who have never done it before (this was my first time) here is how I held the balancer steady while cranking on the main bolt.


Here is a picture of the crankshaft end after the balancer was removed.


1.) Can someone tell me if these chips labeled A,B, and C should cause any worry?

2.) Is the part labeled "D" the seal that people have mentioned in other threads? What is the exact name of the seal to use if I go try to purchase one at NAPA or other store?

3.) How do you remove the seal?

4.) I assume "E" is the key. Should I take that out or just leave it there and put the new HB over it?

Any other advice or obervations are appreciated.

1- A and B I did the sane thing the first time I removed one, the puller bolts were tightened a little too far in and nicked the case. Never caused me any issues, I did check to see if any material was pushed towards the center. If need be sand down any high spots in the case or lightly file the shaft.
The outside ring of the new seal needs a coat of silicon before installation, so it doesn't need to be a perfect circle.
2- Harmonic balancer seal, front crankshaft seal.
3- I use a screwdriver wrapped in tape almost to the tip. And hammer towards the center. All you have to really be careful of is not dinging the aluminum timing chain case. I once tried a seal puller, all it did was tear two notches in the seal.
4- Leave the key, but do inspect it for cracks or whatnot. One of those pieces that can be hard to remove and then seems to fall out and get lost during reassembly. If the balancer goes on too hard, it may be because the key moved and canted.
Check your balancer out, mine usually wear out (the rubber ring) about the same time the seal goes. The oil dripping on the rubber causes it to get soft.

I'm looking at the parts catalog for my 1990. In the exploded view labeled "Crankshaft and Piston 4.0L Engine" I don't see a seal listed. It shows the damper pulley with the bolt and washer and then it shows an oil slinger and crankshaft sprocket. Is the oil slinger the same thing as the seal?

furrymcmonst said:

1.) Can someone tell me if these chips labeled A,B, and C should cause any worry?

2.) Is the part labeled "D" the seal that people have mentioned in other threads? What is the exact name of the seal to use if I go try to purchase one at NAPA or other store?

3.) How do you remove the seal?

4.) I assume "E" is the key. Should I take that out or just leave it there and put the new HB over it?

Any other advice or obervations are appreciated.

Click to expand...

1.) I wouldnt worry about A, and B. Those are explainable from 8-muds response above. The bolts from the harmonic balancer puller did those. No worries if they didnt move any material, or push through. (Visually they look fine to me) As far as C goes however, if i saw that i would really be concearned, but im just anal like that. I would "assume" that this nick would cause the crankshaft to become out of balance, but i dont know for sure. Hopefully someone else can give you feedback on that.

2.) No i dont think that this is the seal that everyone is talking about on this forum. (The seal i think your reffering too is the "Rear Main Seal" which is at the other end of the crankshaft replaceable only by dropping the oil pan). The seal in your picture is appropriatly called your "front main seal". When i purchased my replacement's i told the parts guys at Shucks (aka Checker, Kragen, Advance, murrays etc.) that i needed the "Front crankshaft seal". They were able to find it that way. The times i have purchased these, i also would get the gasket for the timing chain, so im assuming its a "kit".
Make sure you follow your haynes (if you dont have an FSM) when installing this seal. Use a socket or something the same diameter of the seal to keep even force on all around the seal, and then use a rubber mallet or equivelent to pound it on checking to make sure that it doesnt twist too much while sliding into its final location. I used a small amount of copper RTV around the outside section of this seal also to help in "lubing" the install, and to help seal it up when installed completely. Make sure its all the way in also. (Your current one in the picture is NOT installed all the way) It may be best to just go ahead and remove the timing chain cover at the same time to get a better idea of how far it needs to go in, and to get better leverage. This would also prove to be a very very good time to clean the timing cover riding it of all its built up sludge, and i would even go as far as replacing the timing chain since its a relatively inexpensive set. (Get the set from a 1995 Cherokee with the 4.0 H.O its a better design, and fits perfectly (it definely looks like you have a RENIX Cherokee 87-90)).

3.) Removing the seal is easy no matter if you have the timing cover installed or pulled off. Since you dont care about it, just peel it out with a standard screwdriver. Do be carefull not the score the aluminum timing cover too much, but other then that you get the idea.

4.) E is the woodruff key. It rarely gets damaged (from what i have read and from my experience) You can remove it to inspect it if you wish. I havent, so its up to you. What i DO do is angle it slightly downward in the front to allow the harmonic balancer to a.) not get caught up on it, and b.) slide into the correct location a bit easier.


Sorry for the long post i tend to do that, but i am trying to be as informative as possible.
Hope this helps!

I've never had much luck trying to pry them out, I usually end up dinging the aluminum case, maybe piece of plastic, small piece of wood or something between the screwdriver and case might prevent this.
I place my screwdriver carefully and hammer the edge towards the center making a "V" this reduces the diameter and makes removal much easier.
Any small nicks, don't really mean much, just the time wasted to sand or file them down again.
I also smear a little RTV on the end of the shaft before I seat the balancer. Not a big chance of oil leaking out of the bolt hole and around the bolt head, but more of a why not than way type of thing.

I'd not worry about the nicks - even in the crankshaft. It's not far enough from the centre to cause any significant trouble (we run at relatively low crankshaft speeds anyhow,) and I'd be willing to bet it's a spot that's "compressed" instead of "gouged out" - meaning material has probably not been removed, and crankshaft balance has not been significantly altered (I've seen it plenty of times - and I don't worry about it unless I'm building an engine to live somewhere over 5000rpm...)

Yes, that's the seal. If you call it the "Front main seal," people tend to know what you're talking about. You can get it separately, but it will usually need to be ordered - and the timing cover gasket and seal kit costs about a buck more. You pry the old seal out (they make a dedicated tool for the job, but you can use a flathead screwdriver just as easily,) clean the bore, and tap the new one in with a mallet. Go until the metal ring is flush with the seal bore surface, and you'll be fine. You can use a large socket to tap the thing in place, or you can "work around the edge" with just a mallet (I've done both - the socket is easier.) Tips:
1) Smear a light layer of RTV Black over the outside of the seal - the part that is driven into the bore. There are usually some very small nicks in there, and the RTV will help seal them.
2) Remove the Woodruff key (Key E in your pic) using a "magnet on a stick" so you don't lose the thing when you drive the new seal in. Smear some grease on it to hold it in place when you put it back, and make sure you line the keyway up in the HD properly.
3) Don't go too far back trying to grab the seal. There is a flange inside the bore behind the seal (cast into the timing cover,) and you can break a chunk out of it. Breaking out a bit of that won't cause any big trouble, but why take chances?
4) They make a tool to pull seals (called, oddly enough, a "seal puller") that makes the job easier - but a flathead screwdriver will suffice. The puller can give you more leverage, and it's hooked, so you may want to get one when working in smaller areas. I have found that pulling a front main seal with a screwdriver can be a bit difficult, however, and putting a bend in the end (say, 30* about 2-3 inches from the tip) can often help. If you bend a screwdriver, don't throw it away! You'd be surprised how often it can come in handy...

On reinstallation, note that the crankshaft nose screw is torqued to 80 pound-feet with lubricated threads (FSM sez use clean engine oil, but I usually use chassis grease. Same thing, just easier to handle...) and greasing the crankshaft nose and the seal lip doesn't usually go awry, either. Failure to grease the seal lip can result in scuffing the seal, which can result in immediate failure (and repeating the job.) However, changing the seal while you've got it exposed isn't a bad idea - so that should be done. The cost is nominal.

Wow! Thanks for all the great help on this.

As stated before, I'm a mechanical imbecile but progressing thanks to this forum and a relative's help. Here are pictures of the front crankshaft seal I purchased from the dealer today.

1.) Does this look like the right part?
2.) Which end would I view after it has been installed? Or conversely, which end goes in when installing?


(Sorry, I should have PhotoShopped the shadow out but am too lazy.)

Image "B" is the side you should see once it's installed. With seals like this, the "open" side (ref picture "A") should always go to the inside of the part being sealed.

1. You really need one of these in your tool kit.




2. The side with the spring "A" goes in.

I haven't actually removed the old one yet but in looking at the picture of the crankshaft end, it almost looks like someone put one in backwards at an earlier time. (It's hard to tell with all the grease, though.) I'm also fairly certain I didn't create the knicks as I was very careful about how far in I screwed the puller bolts.

I will be finishing up the HB and radiator on Saturday. I have a relative coming over to make sure I don't mess anything up! I'm really looking forward to getting back on the road (without the squeak) with this thing.

One suggestion to all the married men. Make sure the Jeep's heater blows air that is nice and hot. My wife is so cold all the time and she LOVES the Jeep because it warms her right up. (It makes me want to roll the window down.)

furrymcmonst said:

I haven't actually removed the old one yet but in looking at the picture of the crankshaft end, it almost looks like someone put one in backwards at an earlier time. (It's hard to tell with all the grease, though.) I'm also fairly certain I didn't create the knicks as I was very careful about how far in I screwed the puller bolts.

I will be finishing up the HB and radiator on Saturday. I have a relative coming over to make sure I don't mess anything up! I'm really looking forward to getting back on the road (without the squeak) with this thing.

One suggestion to all the married men. Make sure the Jeep's heater blows air that is nice and hot. My wife is so cold all the time and she LOVES the Jeep because it warms her right up. (It makes me want to roll the window down.)

Click to expand...

Yeah, that can cause friction. I'm a cold-weather critter - who happens to be married to someone who doesn't like so much heat, either (granted, I tend to go shirtless until it gets down around 40* - but that's just me. Shorts stay out until it gets consistently below 50*...)

As long as the nicks aren't in a sealing surface (the outside diameter of the shaft,) or have burrs that can gouge the seal lip (which may be broken with a file. Finish file using a fine or very fine cut) you'll be all right.

a little trick to removing or installing the harmonic balancer that I learned is to put the trans in gear and have someone hold the brakes(or put the ebrake on) and then loosen the bolt....but I like your idea of putting a strap through it too.
It works well with my 5speed but probably won't work on an auto because the torque converter has to be spinning to lock up....