Removal of harmonic balancer

[mrsaundep]

Engine Make Mercruiser
Model MCM 140
Serial number 5568367
Displacement 181 CID

I am Trying to pull the harmonic balancer off the crankshaft free end to change the leaking oil seal behind. Engine is pulled and in workshop. I have a balancer puller that fits perfectly. Trouble is it wont come off. The puller bolts are now so tight I am scared something will break. The puller main bolt (centre bolt) thread is quite coarse, but the 3 bolts into the hub have a fine thread and I have pulled these up tight after the main centre bolt went so tight that it would not turn any more. I have now tried heat on the balancer hub (not too much, I am scared of affecting the rubber). I have also applied penetrating oil to shaft/hub and down the keyway. It just wont budge. Any ideas please?

 

[mkast]

Re: Removal of harmonic balancer

Try another puller.

 

[Bondo]

Re: Removal of harmonic balancer

Ayuh,... Wack the big center puller bolt with a BFHammer...

 

[Don S]

Re: Removal of harmonic balancer

The other thing you have to look at is keeping the puller parallel to the dampner. If you have one side of the puller closer to the dampner than the other, you are pulling crooked and it won't come off.

 

[Flysfloatsor]

Re: Removal of harmonic balancer

Its pressed on there and the center witht he corse threads WILL be hard to tun.
Use an impact driver on it.
If you use even a big wrench youll bend the puller shaft with the course threads. (I know, I did it.)

 

[Flysfloatsor]

Re: Removal of harmonic balancer

Make sure you get a harmonic balancer intsaller. its really easy to use. NEVER beat it on with a hammer. Youll destroy the "thrust" face of the crank bearings. Youll also have to remove the timing chain cover to replace that seal... which means youll need a new timing cover gasket. And youll have to scrape the old gasket off prior to re installing.

 

[dan t.]

Re: Removal of harmonic balancer

Why would he have to remove the t/c cover, seal goes in from the outside.

 

[mrsaundep]

Re: Removal of harmonic balancer

Hi,

Damn thing is still not removed. I ensured that the puller was parrallel to the damper using a vernier caliper at all times, and nipped up the 3 bolts nice and evenly each. I did eventually bend the centre bolt as predicted above!! I tried hitting it with a B.F hammer, all to no avail. So I started to pull up the 3 fine threaded bolts a tiny bit each at a time, and eventually the threads on those stripped! 2 of these are out and the 3rd is stuck in! I am starting to think it might have been installed by a previous owners using bearing fit (or something like that)! I have also noted that the rubber between the inner hub and the outer belt pulley has started to work its way out. So I am starting to think I will need to cut this one off and buy and fit a new damper??

Regarding the front c/s seal change, it looks to me on the unit and in the manual that the seal can be changed without removing the timing cover as the seals comes out from the front, as per dan.t above??

 

[Flysfloatsor]

Re: Removal of harmonic balancer

Unless we arent talking about the same thing, cutting off the harmonic damper is NOT and option. I dont even know how youd go about the doing that, they are usually solid steel.

Ok, start over. Go to NAPA and buy a new puller (Under $10, which is prob why that shaft always bends...)

This is dumb but make sure the harmonic damper bolt is removed.

Make sure you put some lube on the corse threads of the center puller shaft (grease works)

Use an impact driver on the corse center shaft, make sure you catch the damper when it falls off.

The timing cover oil seal is needs to be pounded in. Its easier with a block of wood under it. But if you think you can do it with a it on, go for it. Keep in mind they are usually just a thin stamping, so if you pound on it while its on the engine and nothing is behind it, its going to bend.
It will also be difficult to pound it in evenly with the crank shaft stub sticking out.

All this is assuming its about the same as a chevy v8's timing cover oil seal...

 

[mrsaundep]

Re: Removal of harmonic balancer

Hi again,

"This is dumb but make sure the harmonic damper bolt is removed."

There is no damper bolt fitted, the cranskshaft end is drilled tapered (a centre) and there is no thread.

Question 1 - I think I will need to drill and tap the c/s end 7/16 UNF to get the damper back on?

Anyway, I got the thing off but think I cannot re use it. I drew the outter hub off the inner hub with a hydraulic puler, then pulled the hub off the shaft, boy it was tight.

So my balancer is now in 3 bits; inner hub, rubber insert, outer pully - see photo.

Question 2 - can this be reassembled or is it scrap? I know if it does go back together it will need balancing afterwards, but I can get that done at my local electric motor rewind shop.

Question 3 - I have quotes from home (UK) and from US for a replacement damper, and the cheapest is not an OEM part, its quoted as Part No. MP0025-004. Should I avoid this?

Question 4 - Nobody recognises the installation tool ( I have even sent the page from the manual showing it), Any ideas where I can get one.

Finally Flysfloatsor, the shaft seal did come out easy without removing the timing cover, see photo. I plan to use a large socket the same size to gently tap the new one back in
..

Thanks for your help as always....

 

[Flysfloatsor]

Re: Removal of harmonic balancer

1. You will need threads to reinstall the damper.
2. Id get a new one.
3. NON oem parts are great. They meet or exceed OEM in quality.
4. http://www.summitracing.com/search/.../?keyword=harmonic+damper+puller&autoview=SKU
(you can likely find it cheaper)
5. Theats a GREAT idea using the large socket to install. I never thought of that. I also dont own sockets that big.
6. See that little machined groove on the outside of the end of the CS, make sure to replace the key that goes in there. (if you lost it, they are cheap to buy)

 

[dan t.]

Re: Removal of harmonic balancer

If you look inside the new seal you will see a circular spring, these like to fly off when knocking the seal in. To prevent this pack grease around the back side of the seal to stop the spring from jumping off. If the crank is not drilled and tapped the balancer is meant to be driven on, how do you think it got there in the first place?

 

[mrsaundep]

Re: Removal of harmonic balancer

"If the crank is not drilled and tapped the balancer is meant to be driven on, how do you think it got there in the first place?[/QUOTE]

dan.t -I was presuming that it was factory fitted and therefore pressed on. I am concerned about driving it on as I don't want to damage the c/s thrusts and won't know if I have until the worst happens. The old damper was on there so damn tight, if the new one has the same fit I can't see how it will tap on anyway. I will measure the shaft and balancer bore and see what the interference fit is. I am thinking of warming the balancer (heat in an oil bath) and cooling the shaft with ice before I try and install it?

Floatsam, be assured that the "little machined groove" (I would call it a keyway) is well in my thoughts, and the woodruff key is safely waiting for the new balancer! Tks anyway!

 

[fishrdan]

Re: Removal of harmonic balancer

I am thinking of warming the balancer (heat in an oil bath) and cooling the shaft with ice before I try and install it?

I've done that many times, though I think you are going to need more temperature spread to get the balancer on. The last time I warmed the balancer in the oven at 200*F, then froze the crank end with a chunk of dry ice... The balancer slipped right on

 

[dan t.]

Re: Removal of harmonic balancer

The chev 265, 283, and small journal 327 v8s and all chev L6 motors didnt have drilled and tapped cranks, I worked at a GM dealer in the 70s, the instalation tool was a block of oak and a 4 lb hammer, never had any thrust bearing issues. Infact if you look at a service manual from those years it tells you to drive it on, look in the special tool section and you wont find any special ballancer instalation tool untill the drilled and tapped cranks came out.

 

[Flysfloatsor]

Re: Removal of harmonic balancer

The heat/cooling idea seems good. There has to be a way to more gently press it on. Like somehow rigging a horizantal hyd press or something. I will always advise againt hitting anything engine related with a hammer...

 

[Bondo]

Re: Removal of harmonic balancer

The chev 265, 283, and small journal 327 v8s and all chev L6 motors didnt have drilled and tapped cranks, I worked at a GM dealer in the 70s, the instalation tool was a block of oak and a 4 lb hammer, never had any thrust bearing issues.

Ayuh,... Is the motor Outa the boat,..?? it looks it in the picture...
If so,...
Clean the crankshaft snoot, Clean...
Clean the new balancer hub, Clean,... No paint, No nothing...
Then flip the motor up, 'n set it on the Flywheel...
Now, you can beat the new balancer on with yer block of wood, 'n a BFHammer...

 

[kewlkatdady]

Re: Removal of harmonic balancer

I've only build 4-5 engines...

I've always "tapped" or "driven" the HB on with a BFH and a block of wood.

You're not in a batting cage so don't swing for the fences, but ease it on and you'll be fine.

Or use the scientific method of heating and cooling...

Sounds like a good way also...if you feel like jackin with it.

 

[vi]

Re: Removal of harmonic balancer

If you can heat the balancer without messing up the rubber it makes will be easier. We used a small oven in the shop for cam gears for Cummings and stuff, made a big difference just set em on then they cooled in place.

 

[mrsaundep]

Re: Removal of harmonic balancer

Just thought I would post an update..... I purchased a new balancer, warmed it slowly in the oven up to 100deg C. I could not get any dry ice so I put a freeze pack on the shaft and wrapped it around it held in place with an elastic band. With the engine on its side (flywheel down timing gear side up), and using a block of wood and a BFH, the new balancer knocked onto the shaft (with key in). It was tight and took several good knocks, but its there now.