Update-QuickTime Bellhousing won't fit on dowel pins...

[aarvig]

So...long story short, QuickTime sent me a new bellhousing. Go to install it, same problem, exactly. So, I took the bell housing to a local machine shop and asked them to ream the bellhousing dowel pin holes to .500. I get a call back from them today and they tell me the .500 reamer passed right through without taking any metal off.
So, I pulled out a micrometer and mic'd the dowel pins. It is interesting what I found. They are not perfectly round. They vary from .500 to .505 on both sides.
I am wondering what the heck, I should do? Pound out the dowels (which are new), or call the machine shop and have them ream the bell to .506?
Anyone have some ideas?

[boBQuincy]

From what little I know of dowel pins they are made to tight tolerances, 0.005" out of round seems like far too much (unless they are made to provide offset). A press fit of 0.005" also seems like a lot. Unless there is information that this is ok I would replace them.

[NAZ]

Dowels are supposed to be precision ground -- you need to replace these oval shaped dowels. DO NOT ream the bellhousing larger to accommodate faulty dowels.

[3yearplan]

This is somewhat troubling on both fronts, the dowels AND the bellhousing. I haven't seen dowels in odd sizes, such as .506, other than offset dowels and such. So two questions, which is correct: the bellhousing with oversize (in theory) dowel holes, or the odd shaped dowels? In tool and die applications (my field of trade) most dowels are ground with a small flat to allow for the air to escape when inserting a dowel, negating a spring effect. In drivetrain alignment, NOT my field of trade, how important would .005 be ? I know precision is what you're after, and I TOTALLY get that, but what is acceptable and what isn't.

Mike

[aarvig]

Problem solved. It was indeed the faulty dowels. These dowels are not round. Whoever put them in the engine must've hammered them in with a sledge hammer. After hammering these out of the block I installed the end that had been in my block into the bell housing and guess what, it went right in. Turned it over, no such luck.
You can SEE they are not straight:
IMG_5407.jpg

[3yearplan]

A sledgehammer put those in. Good to hear.

[boat737]

After all this, make sure your bellhousing to block is aligned properly. The TKO's max tolerance is only .005" lateral, and .002" parallel if I remember right. There are threads and YopuTubes that go into a lot of detail.

[NAZ]

Just want to echo what boat737 said -- make sure to check concentricity of the bellhousing to the crankshaft and adjust as necessary to bring it into spec. If it's out of tolerance it will lead to poor shifting and premature wear. Any engine that has been line bored will likely require adjustment. There are eccentric dowels made for just this purpose; they come in a variety of offsets.

[aarvig]

Will do guys. I have been wanting to do that but without getting the bell housing even on the block I havent been able to. Hopefully this weekend.

[Frank Messina]

Here's how you deal with this issue. Put your bell housing up on the dowels as far as it will slide on, then hold a light behind the BJ next to the offending dowel and note where the light doesn't pass through. That's your high spot(s). Give it a light dressing with a round file to relieve the interference. Do that for each dowel at all the high spots. Be gentle with the file. The B/H will slip right on.
Frank

[jrcuz]

There is a good you tube video on American powertrain's you tube channel.
JR