Harmonic balancer cap siezed

[Zepman]

Hi all,

I have a small leak coming from either my timing cover or crankshaft seal so I ordered a replacement seal and gasket and got to work stripping the front end. In the process I covered my garage floor with coolant (boy that bottom hose an the rad can shoot out coolant). I thought I'd got there with the rad off but I have hit a snag, in the centre of the balancer I expected to see a big nut holding it on (60 ft/lbs = no bother) and there will be one I am sure but in the centre there is a metal 'cap' or cover and in its centre is a 1/4" allen hole. So I thought insert a 1/4" and loosen. Nope! that SOB is in tight/siezed. I have a lovely tight fitting 1/4" I have WD-40'd it and have hit it the key tentatively with a 4Lb lump hammer and it bounces! I don't want to damage the socket as I'll be totally screwed. Any ideas?

Also the timing cover says "Replace after removal" as it's plastic! My gasket and seal will not fit - why couldn't they use a chevy metal one and standard gasket set? Where do I get a new one? Ideally in Europe.

Added a photo...

[Carl La Fong]

Chevy balancers are a press fit on the crankshaft. get a suitable puller and pull it off. No real need to remove the SHC to pull the balancer but it will have to come out to install the balancer unless you pound it back on which is SOP for most backyard mechanics

[knockdolian]

Chevy balancers are a press fit on the crankshaft. get a suitable puller and pull it off. No real need to remove the SHC to pull the balancer but it will have to come out to install the balancer unless you pound it back on which is SOP for most backyard mechanics

Are the three holes on the spokes threaded and will the balancer come off leaving that centre cap with 1/4 socket ?
I haven’t got an issue with mine but every day is a school day !

[Carl La Fong]

I'm not sure I understand. All BH s with the 350 or 502 have no harmonic damper, just an aluminum pulley to drive the alternator'. You should be able to remove that allen bolt with an impact gun and a 1//4 inch hex socket. Go easy with the impct, just gently rattle it until it comes out. There is no "cap". What you are seeing is the end of the crankshaft

[Zepman]

Hi Carl,

I also am not sure I understand... When I contacted the factory, I told them I had the issue -

Me to the factory - "... I cannot remove what appears to be a protective cap in the centre of the harmonic balancer, it has a ¼” allen socket. I attach a photograph. I have tried everything I can with penetrant and extension bars and I am at the stage of damaging the ¼” socket.

Please can you confirm that it is a normal thread (not reverse left-handed) and anti-clockwise is the way to release it. And do you have any tips on removing it – I assume there is a 7/16”-20 balancer bolt behind it holding the balancer on."

They responded - "You are doing everything correct. It is a normal thread bolt (not reverse) Often times we have seen where those bolts get jammed seized up. "

They went on to suggest - ..."and weld a nut to the head of the socket bolt. Make sure to take all the proper cautions before welding ( unplug battery, grind clean spot for weld, etc)"

To knockdolian -

The balancer does have three tapped holes and it certainly appears that the puller would just pull on itself if I tried attaching a puller pressing against the centre...

[knockdolian]

Zepman, I’ve sent you a PM

[Zepman]

Hi guys,

Episode 1 of balancer saga over.

It turns out that the 'cap' is a large thick washer holding the balancer on. Due to lack of space behind the rad BH decided to secure the balancer with the washer held in by a 7/16"-20 countersunk bolt 1/4" allen socketed which centres in the countersunk washer. Image attached.



As you can see, if you apply heat to the bolt it has to reach far down to the loctited threads in the crank - not so good. I welded a nut to the cap but a large nut only welds to the washer. Anyway I used a breaker bar and yes it turned. Then I realised it was just spinning and not coming out at all. On inspection I realised the allen socket wasn't spinning so I put a 1/4" allen key on it and yanked. I felt it turn and the nut/washer immediately slackened. It was then easy to undo the countersunk bolt and washer. The washer had rusted in so needs a clean up too.



I realised that I needed that bolt due to the tight clearance behind the rad to refit the balancer so ....



The first pic is my cleaned up washer and bolt after I sawed the 30mm nut off it. I was lucky as the bolt threads took a lot of cleaning of hardened loctite. It's amazing to think that you are expected to tighten the 1/4" allen to 60 ft/lbs - I'll use medium loctite

The balancer is at this moment still there so expect a Part 2.

[Zepman]

Hi All, or few as it may be,

I pulled the balancer and it deformed the puller as I did it, but it did the job safely for the balancer and crank. It revealed the very dirty timing cover it certainly looks like the balancer oil seal has gone.

The replacement is BY 12562818 SBC Plastic GM Vortec this is the "one without the timing sensor hole". When you remove it check whether the new one has rubber grommets around the bolt holes, mine didn't so I had to reuse the old ones. Due to the lip on the oil pan gasket being very deep I had to partially drop the pan to get the new cover on properly.




And the alternator bracket has to be removed as it sits under the front right corner of the pan. The timing cover has a very good looking rubber gasket but I also used RTV for insurance. It fitted perfectly and easily.

I used an SBC balancer installation tool, I slipped on the balancer, lined up the keyway and threaded in the installer pressure nut which has a bearing and washer that turns on the balancer to avoid galling and rotation. The right tools make the difference and it glided on. I inserted the countersunk washer and 1/4" allen bolt and set up my torque-wrench for 60 ft/lbs and prayed.



The bolt took the 60 ft/lbs with no visible damage, the allen wrench was a different story, this is what 60 ft/lbs does to a 1/4" wrench...



The job is done, now to put back the rad etc with fresh coolant. A small point, as I have a thermostat I thought I would avoid air locks there by filling through the top hose - don't. Although I have drilled the thermostat it still can't take a lot of coolant straight in.

On reflection it's not a major job, it just takes a bit of parts removal to get to the cover - it's the balancer lock bolt that was the snag and there's no clearance behind the rad to use a normal bolt.

I'm looking forward to burning some fossil fuel again which currently in the UK is around $10.10 a British gallon!

[502wingman]

have fun burning fuel again

[knockdolian]

Good to see you got it sorted. I was wondering. Well done. I think I will put up with the leak if I get one
Back on the road just in time for £2 a ltr