I am converting a 235 to a 700r4 trans. The instructions for the adapter plate that I have ask about checking the concentricity of the crankshaft to the transmission seal mounting bore.. I am trying to figure out how to do that? Any help would be greatly appreciated. Trying to get this completed by Hot Rod Reunion next Wednesday. Thank you, John
You could mount dial test indicator on the crank, bolt the transmission (without torque converter) to the engine without the bottom cover, adjust the test indicator to touch the seal bore, and slowly turn the engine. Read the dial for runout. OOOOOORRRRRRRR just bolt it up, and accept that the statement is probably for liability?
haha! I appreciate it, and also think that it is a liability thing.. but I figured I'd try doing it anyways, I just can't get the dial indicator to mount correctly on the flexplate to get an accurate reading. I'm driving this thing down to Kentucky from Northern Indiana next Wednesday, and I'm just wanting to be safe.
those guys use to have a tool for doing the line up that they would loan you with deposit. check with larrow and sons in Sandy Oregon, I used theirs years ago or go to the inlinners site Inlinners international
Are you using a dial indicator or a test indicator? How about a test indicator with a flat spade like mine shown. Take out a couple of the flexplate bolts and figure out a way to clamp the spade to the face of the flexplate. Maybe take a short piece of flat stock and drill two holes in it that line up with the flexplate holes, and clamp it using that. Or maybe one bolt and a big fender washer. Langdon claims 0.012" of runout is acceptable. (http://stoveboltengineco.com/2012/07/transmission-update/)
checking the concentricity of some feature on the transmission or bellhousing relative to the crankshaft used to be in many factory shop manuals. http://chevy.oldcarmanualproject.com/shop/1949_53/06engine/6_106.HTM the Studebaker guys know they need to do it when trans swapping.
I am using a digital dial indicator with a magnetic base, and I am attaching the base to the flexplate, and I've checked around the pump shaft, the input shaft, and where the torque converter mounts and all of the measurements vary. I am not 100% sure which measurements to go by or which ones are accurate. Has anyone done this process? I appreciate all of the help everyone has given on this. Thank you.
Correct me if I am wrong, but would you be checking the concentricity of the crank flange to the seal bore? Since the variable in this case is the concentricity of the crank flange, then why not just mount a dial indicator to the back of the engine block and place ball on the flange and rotate the crank. I would think it would be true within .005" if it was worth anything. Another possible approach would be mounting the converter to the flywheel, then check the pump sealing surface of the converter in relation to the engine block. This would tell you if your setup is out of round enough to hurt seal, etc. Checking to the seal bore is more for alignment than concentricity. The adapter should have been fabricated using the crankshaft as the datum point. If so, then the adapter is already aligned.
When you say the measurements vary, how so? You are trying to take a runout measurement. The absolute value of your measurement is irrelevant. You need to make sure the needle on the dial indicator doesn't move more than .012" total during the entire revolution. d2 Willys: Langdon claims that they made the adapter to fit the "average" bellhousing. The tolerances allowed by the bellhousing manufacturer were big enough that some bellhousings aren't well enough aligned, so they want you to check concentricity. If it is concentric (within .012), it is aligned.
Interesting! I would however describe it more like "offset" rather than concentricity. To me, concentricity is an out of roundness of a revolving part. If the crankshaft flange was out of round in comparison with the block, then I would agree. But this sounds like the bell housings and adapter may have offset issues.
Well we ended up figuring out how to mount the dial indicator on the flexplate, and we rode it along the input shaft to check run out.. it ended up being .008" which is under the .012" allowed (per Langdons adapter plate). So we went ahead and put it in and are going to have it up and running by the weekend. I definitely appreciate all of the help everyone gave, it was nice having some sources to go to for this. Thanks everyone!