is there a motor side and trans side to a flywheel??? (th400 and pont. 400ci)
the old flywheel i took off has the teeth with the slant facing the trans-side. shouldn't this be the other-way around with the slanted teeth facing the starter and motor-side?
also there is a spacer/washer that came off with the f/wheel, does it go on the crank before the f/wheel, like a spacer or after f/wheel and act like a big washer?
ok turned the flywheel around with the slanted teeth facing the starter but bolt holes will not aline. some will but not all. i can only get all the holes to aline if i install the f/wheel with the slant teeth facing trans but then starter needs a butload of shim's to make it work?
old flywheel looks the same, teeth just not as deep groved.
the flexplate or flywheel will only bolt on one way... the right way. the shim normally goes on the outside, but i have seen them between the crank and flexplate.
how thick is a buttload? will the starter bolt up at all without them? the shims are for aligning the bendix in the starter, and should not be needed just to bolt it up, only to get the teeth to mesh properly. could you have an incorrect part?
The flywheel only aligns with the slanted teeth facing the trans. even the old f/wheel was mounts the same way. The starter will bolt up with out the shims, but the bendix will hits the f/wheel when I try to start the motor. To get the bendix to mess correctly I have to add about 3/8in" of shims. I’m going to try the old f/wheel in the morning to see if it is the same circumference as the new one. Does anyone have a good part number for a flywheel for a 69 Pontiac 400-auto trans.? And if so where is it located? I can’t find it on either flywheel.
The tapered/square edge means nothing. The flywheel will work either way it fits. Your starter situation sounds normal. If you can bolt it up and shim the starter to make it work you are good to go. Jim PS Pontiac engines are internally balanced and do not use the flywheel to balance the engine like some externally balanced engines.
The slant edge faces the tranny on mine also. What you really need to watch out for is how the torque converter bolts to the flexplate.
Check the clearance between the torque converter bolt "pads" and the mounting surface on the flexplate. You have to make sure the torque converter is engaged/indexed into the tranny correctly prior to this check. Then you mount the tranny to the engine. Do not connect the torque converter to the flexplate, but instead measure the distance. Make sure this is up to the factory specs. If the gap is to wide then the torque converter will be pulled to far out of the input shaft area (you will need to shim to get the correct gap). If the gap is to small, or non-existant the torque converter is not engaged correctly with the tranny.
The gap specs for my Pontiac 350 and 200-4R are between 3/16"-1/4" gap. I'm not sure if this is the same for your 400/400 combo.
Many flywheels don't even have a tapered side. You don't need to worry about the torque converter position because the nose goes in the end of the crank. There is no way it can disengage from the pump when the trans is bolted to the engine. Just make sure that the torque convertor is all the way in the trans pump when you start bolting up so you don't put pressure on the pump. Jim
the distance between the converter and flexplate does need to be measured. if the gap is too small, the converter is likely not all the way in, and will cause damage when boltiung the engine to the trans. if the gap is too wide, the converter will be pulled off the pump impeller when tightening the 3 bolts to mate the converter and flexplate (and get the nose in the crank).
you cant really measure too small a gap, as the trans should not be bolted to the engine if the converter sticks out to the bellhousing mating surface. there should be enough room to get the flexplate in there, and still not come flush with the bellhousing before putting together.
i have never actually seen one which had the wrong clearence, but have heard horror stories, so i always check. if it is more than 1/8" find the specs.
They may have different part numbers but they are interchangeable. Another way you can tell which way a flexplate goes on is the indented holes where the torque converter bolts up are indented towards the torque converter. Jim
Hey guys, Thanks for all the great information. I’ve been all over town today looking at flywheels at every parts-store around here that had one, and they all were the same as the one I have now. The part # on the flywheel ring is …<> 7 GM 9779076… it still will only go on the one way, with the teeth towards the transmission. The flywheel is flat all the way around and does NOT have any pads or indents for the t-converter bolt to bolt against. When it’s installed there is a gap less than ½ inch between it and the t-converter. But there isn’t enough of a gap between the flywheel and front of the starter bendix. It’s close when motor is off, but when it’s running and in gear the flywheel rubs the front of the bendix (not the teeth, just the side of the flywheel ring and the front of the bendix. I installed the small shim I had between the crank and the flywheel and re-torque the flywheel bolts, but I still need more space. Does anyone know where I can find the flywheel shims for Pontiac’s? The only ones I can find around here and on the web, is for a Chevy. Will these work or can they be made to fit without a balance problem? Can I use a single washer on each bolt between flywheel and crank and lock-tight the bolt or is this just a disaster waiting to happen. HELP I’m ready to get this baby back on the road!!!!
You are over-analyzing this. Forget about all that converter clearance garbage. If the converter can rotate freely after the trans is bolted up you have enough clearance. Just bolt the flywheel on with NO shims and shim the starter. The starter can have up to a 1/4" of shims. ALL pontiac engines like yours have shims on the starter. Do it to it and you will be rollin soon. Jim