Dropped off your schematics on friday afternoon, the machinist said it shouldn't' be a problem however he wants me to drop the bearing off to make sure its a proper fit..

He said 2 hours.. around $125 and it would be done before labor day weekend.

 

That sounds reasonable.

 

That is reasonable, for sure. But make sure he doesn't miss that one of the bolt holes isn't evenly spaced.

 

I noticed that on the plans. Surely he wont, it's right there on the dimensions.

 

There is so much useful information in this thread that it has to be read many times over. Well done !!
I am planning a ZF swap in my '81 bronco as well, and over the next few months it will be outfitted for an extensive road-trip from Vancouver, BC to Brazil... and beyond. A 10 week trip planed to take place in the fall 2014...
Anyhow - is there anyone on this thread that have or know of someone who has the factory spec for a 400 (or even 351m) flywheel w/measurements and tolerances? It would be very much appreciated... I am in a situation where I can have this made and incorporate the measurements from your spacer and tap it for a 12" clutch while I am here in Europe before I return to BC.... and to find an old one to measure is close to impossible... any help would be amazing.... cheers

 

The tolerances are in the Engine manual but they're pretty general - out-of-round and stuff like that, stuff that's useful only when you're seriously rebuilding an engine. Didn't see anything as far as tooth count & spacing a d hole size & location, etc. but that stuff might be someplace else.

 

Agreed. I'd looked at the Engine manual recently so knew what is there. And, being a wanna-be machinist I know what I would need in order to make the flywheel and very little of that is available in the spec's. On top of that, even though I could, with a lot of time, figure out the bolt spacing, tooth count, etc I still have no way of finding the weight accurately and, most importantly, cannot even approach determining the balance.

I've looked for flywheels on-line and find them in the $400 range, which is outrageous when a whole engine goes for $250ish. Tim Meyer sells rotating assemblies for the 400 for $1300 for a crank, flywheel, rods, pistons, rings, gaskets, bearings, etc. So surely he would sell a flywheel itself for far less. And you would know it will work instead of having had one machined that might not work when you try to install it.

 

He missed it.. however hes going to fix it.

which kind of brings on one more question, which side of the spacer is this looking down on? The side which mates with the crank or the side that the flywheel bolts too? Just want to make double sure the hole is drilled in the correct orientation.

 

Bummer!

Actually, that is the rear view of the crank - as it says.

Here's the whole drawing again, where you can see that the crank and spacer side views are below their respective rear views.

 

You were right on that one Gary. I thought for sure any kind of machinist would have picked right up on that different spacing measurement.

Now how does he fix it without starting over again? Unless he welds it up.

 

For this job, welding the hole up to re-drill it, isn't really an option.

The heat & the slight difference in materials (the spacer & the welding wire/electrode) usually causes a harder area that doesn't cleanly machine off.......so even though it might only be .001"-.002" bump, it will upset the flywheel run-out.

He'll probably drill six new holes between the existing ones. If not, I would check the run-out before you assemble the clutch.

 

If I chumped the cut, I would just do it over.
Might re-drill if it was mine, but a customer is paying to have it right.

 

I agree totally.

I was just replying in light of the "however, he's going to fix it" comment.

 

I suppose it is just a spacer and drilling 6 new holes wouldn't hurt it, but like Jim is saying I would want a new piece of stock.

 

I agree - I wouldn't just re drill. And I sure wouldn't weld it up. I would start over. But there are those, like my upholsterer, that have no shame.