351W Harmonic Balance problems

[fatboy4211]

maybe i missed it but have you isolated it to the engine? If it vibrates at 50 bad, put it in neutral and let idle and confirm that it changes. It should also vibrate just revving it up to the same rpm while parked.

Try different things to figure out if it is transmission, drive shaft, wheels, brakes, or engine.

Unless you already have and i just overlooked it!

yep tried everything so far without removing tranny. Thanks

 

[Tiko433]

I just know someone with more brains would know.....

On a side note....I thought the Explorer front dress used a plastic fan? I've never seen a metal fan in the junk yards....I guess it has been changed?

Tim

I have a 97 Explorer front dress . It has a metal fan like that

 

[rguest3]

4211 - The correct 28oz Balancer is only half of the equation. You will have to confirm you also have a correct 28oz Flexplate or Flywheel for your 351W.

The correct Balancer and Flexplate / Flywheel is critical. This is mandatory when completing the build on any engine.

 

[bronconut73]

What application did you use for your new damper? And what is the engine out of originally?
Later model obviously, due to the serpentine belt setup. Or it could have been swapped on to the engine as well as the engine swapping into the Bronco.

Bought engine off of For Sale item here on site. Came out of a bronco in Houston and he stated it was a running 302 when he pulled it out of his bronco. I took it straight to a motor builder to rebuild and he informed me it was a 351w. Afterwards water entered one of the cylinders and busted the block. He replaced the block and it was running nicely. Suddenly the light vibration went ballistic. And I have no clue as to engine year model.

When I had a similar problem the wiring order was wrong.
A high lift 302 cam in a 351W so it needed to be the 302 firing order, not the 5.0 HO or 351W order.
So,...surprisingly it would idle okay but shake like hell at higher rpm.

But that's just my dumb luck...

 

[86Horn_EB_77]

Hey Guys - I agree that those pics show a 96-01 Explorer 302 Serp Drive (with an aftermarket AC unit) but... I don't think that's an Explorer balancer or crank pulley - the Explorer has a one-piece integrated damper & pulley unit.. not a bolt-on three bolt damper as shown in his first post.

That's why you have to send the entire Explorer damper+pulley off to get rebalanced at Damper Dudes - I didn't think there were any Ford 351W (28oz balance) dampers that work with the Explorer serp - but he appears to have something that works (or at least the belt lines up - I have no clue it's a 28oz or 50oz balance).

And as mentioned above - if that's a 50oz balancer on a 351W... then you've gotta get a 28oz balancer AND a 28oz flywheel/flexplate - which means dropping the trans or pulling the engine... Yea. Not.

EDIT: Oh crap wait - those 3 bolt holes are probably just for the damper puller - if the damper & crank pulley are one cast piece - then for sure it is a 50oz Explorer 302 damper - and you need to get it rebalanced by somebody to 28oz for a 351W.