After bolting up trans to motor, there is .625" gap between the flywheel and converter. Is that normal? Let the converter slide forward and Just bolt it up? Will that cause disengagement from pump? What is the formula for the correct converter? I have a 450hp/500ft/lbs torque. Mild cam (honestly dont have the cam specs) 427 Big Block. 3400 lbs pickup, 4:10 gear, TH400 trans. The guy that rebuilt the trans suggested 2300 to 2600 converter. I had everything installed and just drove it to shake it down, and has a drive line vibration in third gear at 2500rpm plus
Ideally, you want about 1/8 inch gap with the converter pushed all the way into the pump. You can shim with flat washers. Is your flex plate correct for the crank? The stall speed needs to match the cam.
Should be OK.The rookie mistake is not seating the converter correctly .When that happens the converter is real tight against the flex plate.If yours will move forward a bit it should all be seated correctly.
A full, exact... .625"..? More like .63" While .63 sounds a little on the large side, yes. Like was mentioned above, "some" gap is required so the trans pump is not damaged. It all depends on the machined cuts in the converted tube, and if the trans. pump gear was put in correctly. If the pump gear was put in backward, then a larger gap more like what you have would sound reasonable. It should not be a problem. Although, depending on how the trans. guy is measuring the converter rpm, it sounds like a loose converter for your combination. You'll have a tire burner for sure. Mike
5/8" is WAY too much. You will likely pull the hub out of the pump gear. You need to find the problem before you tear up the pump. More than 1 /4" clearance can be a problem and would need shimming. Bill
0.0625" would be fine. That's 1/16". 0.625" is way too much. That's 5/8". I don't know how this is possible, unless maybe you have a 1/2" thick plate between the block and transmission case? As for picking the right converter....2500 stall for use with a mild cam is probably fine. Depending what your definition of "mild" is.
Not sure what your using to actually get your number. Find a nice 1/8" drill bit and slide the shank end in the gap between bolt boss and converter tab. If it's snug your Golden. If you can put a 5/8" drill in that space make a spacer.
5/8 inch clearance means the converter is probably just barely catching the pump gear tangs. If it has a rear motor plate that’s your problem. Like others have said, should be about 1/8 clearance. Vibration is probably drive line angle or driveshaft. Rarely is the trans the cause of a vibration especially in hi gear. Sent from my iPad using The H.A.M.B. mobile app
Vibration is probably centering the convertor off the bolt holes instead of the crank. Convertor snout may be out of the crank at more than a half inch?
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