Engine/trans alignment

[bizjetmech]

Okay, so I'm about ready to bolt my new motor onto my numbers matching tranny.

I know that the alignment between the c/line of the crank and the c/line of the tranny/torque converter need to be close, to prevent breakage and/or premature wear.

Soooooo........if this is so important, how did they check this at the factory? Or did they even bother? I'm assuming that the engines came from one plant, and the transmissions/bellhousings another.

 

[pettybludart]

I believe the dowel pins in the back of the block,help make sure the tranny is centered.JMO.

 

[bizjetmech]

True. You would think. But Ehrenberg and the transmission vendors always recommend that you check it, and adjust it with offset dowels. Trouble is, you can't really do it correctly without the transmission torn down to the bare case.

Unless, of course, the factory figured out a way to do it. If it was that critical, the factory would have to have a means of measuring assembled transmissions/bellhousings, and assembled engines, and mating them with dowel pins with the proper offset.

I'd like to check it, just to be thorough; but if it requires a transmission disassembly, it's not going to get done, and I'm not going to lose any sleep over it.

 

[bizjetmech]

BTW.......what a coincidence.

My car is a "Petty Blue" '73 too. Except mine has the black "over the roof" stripes, and the hood scoop with black stripes.

 

[RustyRatRod]

I don't think it's something the factory saw fit to waste time with. All that stuff was figured out on blueprints and prototypes and then when it was ironed out, they let the **** hit the fan on the assembly line and didn't look back. I think the majority of the alignment problems come in with mixin and matchin factory and aftermarket parts. I'm sure people have had problems with factory pieces before, but on a small scale in comparison. Actually thinkin about, that is somethin I have never had a problem with.

 

[fishy68]

I agree with Strokerscamp that the factory didn't worry about the small stuff. Heck if you ever looked in a factory service manual at the specification range of clearances in a torqueflite you'd realize you probably don't even have to measure hardly anything. Just slap it together and it's a 99% chance it'll be in that sloppy range.

Things have progressed in the performance world and racers are always looking for the extra .05 second. That and the fact that performance torqueflites are built with MUCH tighter tolerances than the factory did so things like the engine to trans. alignment is now being checked. I know of no way to do it without the trans. torn down. Wish I did because next month I will be installing a new engine in my Cuda and plan on checking the alignment and to do that I have to tear down my 7,000 mile perfectly working 727. If you figure out a way let us all know, LOL

 

[oldkimmer]

...............Dont worry about it.........tranny shops install thousands and never measure anything, and no problems.....kim.........

 

[oldkimmer]

...........Hey fishy, just do it like the factory did...........isn't it good enough.................kim.................

 

[RustyRatRod]

...........Hey fishy, just do it like the factory did...........isn't it good enough.................kim.................

Yeah do it like the factory did...... and don't do it. LMAO. I'm sure it'll come out fine.

 

[fishy68]

...........Hey fishy, just do it like the factory did...........isn't it good enough.................kim.................

Yeah do it like the factory did...... and don't do it. LMAO. I'm sure it'll come out fine.

I don't doubt your both right. Don't know why I worry about the small stuff, LOL.... After all it's not a race car.

Come to think of it I have a bare case in the parts shed. I think I'll check it just to see how far off it is.

 

[highflyer]

IM GOING TO BUILD A PLATE THAT HOLDS A ROD WITH A DIAL INDICATOR ON THE END OF IT THEN ILL [WHOOPS.]then ill spin the plate inside the bell 5.125 bore and dial indicater inside the bearing bore and see what the total runout is..j

 

[fishy68]

IM GOING TO BUILD A PLATE THAT HOLDS A ROD WITH A DIAL INDICATOR ON THE END OF IT THEN ILL [WHOOPS.]then ill spin the plate inside the bell 5.125 bore and dial indicater inside the bearing bore and see what the total runout is..j

What is the plate going to be bolted to? I assume you mean you'll be checking from the bellhousing for a manual trans. into the rear main on a bare block? The only problem with that is unless you have a miniature dial indicator you'll have to angle it into the rear main and by doing that you many not get a accurate reading. Wouldn't it be better to install the crank into the block and attach the dial indicator to it and spin the crank checking off that to the bore of the bellhousing?

 

[highflyer]

let me try that again...ill make a plate to sit inside the bore of the bell with a shoulder so it cant fall thru..i cant spin the crank cause the motor is built..not very easily anyway...so ill spin the plate holding the rod and indicator into the back of the crank..minus cl and pr plate..while spinning the plate slowly,ill read tir..total indicator runout..jim