425 harmonic balancer

harascho · Postby **harascho** » Wed Jan 01, 2014 9:39 am

As I am visiting the machine shop tomorrow.... does anyone have an exact dimension of the harmonic balancer's diameter where the front oil seal rides on? It' a '66 425 V8 out of my Toronado. I had to buy an aftermarket balancer 'cause mine fell apart... I have to work a little on the counterweight to make it fit..and I realized the outer diameter is 51,38mm and the oil seal sits a little too tight for my personal taste.. data from the national oil seal say it is for a 2" shaft and that's only 50,8mm. So before I modify mine I like to confirm with another original balancer...to be on the safe side. My original one is not for measuring.. the surface is shot... I modified it for a different oil seal and had to realize that I cannot find a company to overhaul the rubber part.

But that was only one part of the mess, after the oil seal surface was clean we found a crack through the complete inner balancer part, right where the crankshaft key is located.... that was it with the old Olds 425 balancer....

Thx a lot... and a happy new year for all of you

waterzap · Postby **waterzap** » Thu Jan 02, 2014 10:28 am

I bought an aftermarket one. Does not fit. Got a rebuilt one on ebay for around $150. Works perfectly.

bcroe · Postby **bcroe** » Thu Jan 02, 2014 10:15 pm

waterzap wrote:I bought an aftermarket one. Does not fit. Got a rebuilt one on ebay for around $150. Works perfectly.

You bought a FluiDamper, and it doesn't fit? I have them on 5 cars, got fed up with dampers
falling apart. I believe the dia was 1.5", or some such round number. Hope the 425 is the
same as the 350/403/455 I use.

Realize that the early dampers slide on. The late 70s were a friction fit, 1/2 mill undersized.
FluiDampers were 1.5 mil undersized, mostly due to the anodizing. I put something in the
keyway and used a ball hone to open it up, problem solved. I have a tool for the balancer,
must have. On the FWD car, had to clearance the front engine support a bit. Bruce Roe

waterzap · Postby **waterzap** » Fri Jan 03, 2014 11:22 am

No, was one similar to the one on the bottom pic. They don’t fit, at least not in the Toronado.

bcroe · Postby **bcroe** » Fri Jan 03, 2014 6:07 pm

waterzap wrote:No, was one similar to the one on the bottom pic. They don’t fit, at least not in the Toronado.

That looks just like mine; used on 350/403 FWD/RWD here. Can't see the weight side,
what didn't fit? Bruce

harascho · Postby **harascho** » Sun Jan 05, 2014 3:02 am

What doesn't fit is the counterweight. It might be ok with a RWD car but in the FWD Toronado the weight hits the front engine mount bracket. I will trim the weight about 2 - 3mm from the bottom side. That won't take a lot of weight away and it will clear the bracket...

I will post some pics when it's done..

Harald

bcroe · Postby **bcroe** » Sun Jan 05, 2014 8:36 am

harascho wrote: What doesn't fit is the counterweight. It might be ok with a RWD car but in the FWD Toronado the weight hits the front engine mount bracket. I will trim the weight about 2 - 3mm from the bottom side. That won't take a lot of weight away and it will clear the bracket... I will post some pics when it's done.. Harald

Yes, that is what happened on my 79 Toro/Eldo. But I ground a little off the front engine
mount and left the counterweight alone. The advantage of course is it doesn't affect the
balance of the engine. The 66-78 mount is different from the 79-85 mount, isn't it
still possible? Bruce Roe

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