Quicktime Run-out off....Normal?

[badazz81z28]

I heard nothing but great things about this bell....but I just checked run out and top to bottom was .011 and side to side was .006 (and yea I did divide the # in half).



I guess off-set dowels again

[garys 68]

normal, they all reccomend checking and using offset dowels

[68sixspeed]

I have yet to find one that is "on" I've checked several QuickTime, GM, and McLeod too. Even motor to motor (LS1, etc) varies so that tells me there is significant error in the bell housings and blocks.

[Mkelcy]

I have yet to find one that is "on" I've checked several QuickTime, GM, and McLeod too. Even motor to motor (LS1, etc) varies so that tells me there is significant error in the bell housings and blocks.

How do you check runout on a bellhousing designed for a T56?

[Mr Nick]

My RS600 with a QT scatter-shield needed offset bushing.

[68sixspeed]

easiest method I've found is to take the front plate off the transmission. The input bearing race is a slip fit, remove that and use the bearing bore in the aluminum front plate as the surface to indicate. Then the options to correct it are either offset dowels at the block, or removing the factory dowels from the trans to bell housing plate and installing new dowels.

I'm thinking this is also a factor with a lot of cars, even 4th/5th gen camaros where one car shifts like butter and another has shifting problems - the factory tolerances are all over the place, and the aftermarket isn't much better. Randy (Probell) had a bad run with this last year and we ended up indicating a bunch of combos and even took some bell housings to a coordinate measuring machine. I redid the excersize this spring when I did the LS swap on my car and found similar problems, ~.015 vertically, .005 left to right. I got it within .0025 and called it good enough. (who knows how much it moves as the motor and bell housing/trans get hot either?) -Dan