How close is close enough??

[green69rt]

I've arrived at the point that I want to install some frame rail connectors and have followed several other threads.  I've made so many measurements on the frame that I can't count them.  A level across the rockers shows that things are within 1/8 inch from side to side and also across the front frame rails.  Pic #1 show the level.  Is this close enough?  Thje FSM gives a 1/4 inch range for it's measurements. 

The second question is where to support the car when I install the connectors.  I currently support the car underneath the torsion bar cross member wher it meets the front frame rails and in the rear I am supporting half way between the front an rear spring hangers (pic #2.)  I am thinking of moving the front support to a point directly under the shock support towers.  Any thoughts.  I'm I worried about nothing??

[JB400]

Considering how poorly these cars were built, that might be fine.  If you want exact, you can make up some jackstands with some big bolts in them and level your car that way.  And use a digital level

Did you check and make sure your board was straight? They do have a crown (bow) to them.  What type of frame connectors are you using?  It would probably be a good idea to install the floor first on some types

[green69rt]

Yeap, the board is straight and the level is calibrated.  Seems that everytime I add something to this car it gets a new measurement and push.  Been good so far but I keep wondering if I'm going to end up crawfishing down the road?  Using the US cartools units.

[Patronus]

I dont have connectors on the b body yet, but I would prefer to weld them in with the weight on the wheels. A drive-on lift would be ideal. 

[Mike DC]

I have been through this operation too, and the others are right - these cars are too sloppy to expect precise numbers.  I have measured some dimensions on two original cars and seen differences as wide as half an inch.

But having said that, the subframes & floors had a lesser amount of slop allowed than the higher up structures of the body.  Those big circular holes in the rails/etc were used to align things (the factory dropped the parts onto metal rods to hold them all in shape during welding).



I ended up supporting the car at both the front and rear ends of the 4 main subframe rails, for a total of 8 jackstands under the car.  I used cheapie trailer jacks which are screw-adjustable.  (No, those jacks are not meant to hold the weight of a car.  But we're dealing with a disassembled unibody and we're using a bunch of jacks on it at once.)  

I got the whole car sitting level according to FSM specs, with all 8 jacks holding it there, and welded away.  Turned out fine.  I wasn't concerned about getting it level on a bubble with the planet.  I just made sure it was not sitting in a sagged/distorted position at the time.      

[FLG]

I dont have connectors on the b body yet, but I would prefer to weld them in with the weight on the wheels. A drive-on lift would be ideal. 

Agreed.

Always better to weld them when the car is on its wheels. Id wait until your car is a little more back together. Most connectors either go thru the floor slightly or weld to the floor pans as well as the front and rear subframes.

[green69rt]

I have been through this operation too, and the others are right - these cars are too sloppy to expect precise numbers.  I have measured some dimensions on two original cars and seen differences as wide as half an inch.

But having said that, the subframes & floors had a lesser amount of slop allowed than the higher up structures of the body.  Those big circular holes in the rails/etc were used to align things (the factory dropped the parts onto metal rods to hold them all in shape during welding).



I ended up supporting the car at both the front and rear ends of the 4 main subframe rails, for a total of 8 jackstands under the car.  I used cheapie trailer jacks which are screw-adjustable.  (No, those jacks are not meant to hold the weight of a car.  But we're dealing with a disassembled unibody and we're using a bunch of jacks on it at once.)  

I got the whole car sitting level according to FSM specs, with all 8 jacks holding it there, and welded away.  Turned out fine.  I wasn't concerned about getting it level on a bubble with the planet.  I just made sure it was not sitting in a sagged/distorted position at the time.      

I like your method.   Also I am still a little gunshy about welding them in fully so I think I will just tack them in fairly substantially so I can cut them out more easily if I have to.   Then when the car is on its wheels I'll check things out and finish the welds.   Thanks to all for clarifying things for me.

[tan top]

  looking good nice work !! 

I've arrived at the point that I want to install some frame rail connectors and have followed several other threads.  I've made so many measurements on the frame that I can't count them.  A level across the rockers shows that things are within 1/8 inch from side to side and also across the front frame rails.  Pic #1 show the level.  Is this close enough?  Thje FSM gives a 1/4 inch range for it's measurements.  

if the FSM says 1/4 + - , its good to go  , but if it were me  , ( yeah i'm nutts on somethings) seeing as you got the car all appart ,  would try getting the bubble little more central ,   would be bothering me , if i left it ! thinking could i of got it better !or tried to  ,

The second question is where to support the car when I install the connectors.  I currently support the car underneath the torsion bar cross member wher it meets the front frame rails and in the rear I am supporting half way between the front an rear spring hangers (pic #2.)  I am thinking of moving the front support to a point directly under the shock support towers.  Any thoughts.  I'm I worried about nothing??

wait till you have welded it up & its a a complete empty body shell with panels , doors aligned up etc etc , then weld the frame connectors in ,  thats how i done mine  

other way is ,  wait till car all built up with suspension motor / running gear etcetc , then with full weight on the wheels , weld them in  

[richRTSE]

Just a couple of suggestions here....

I installed the USCartool frame connectors and a full AMD floor also. The floorpan did need a little persuasion to fit down against the subframes/crossmember correctly, and the frame connectors needed a fair amount of trimming/grinding to fit up against the bottom of the floor pan. I would definately install the pan first, then the connectors....

I'm not sure how much weight is still on the front of your car (not much, as it appears you have it pretty well stripped to a shell), but you may want to install a door and make sure it opens and closes correctly and that the car is not bowing in reverse, and support the very front of the car if you need to....

If you plan on running an emergency brake, you may want to figure out where you're gonna route it before you weld in the connectors. I welded a 1/2" tube thru the connector at an angle for the cable, and it came out pretty nice....

[green69rt]

Just a couple of suggestions here....
I installed the USCartool frame connectors and a full AMD floor also. The floorpan did need a little persuasion to fit down against the subframes/crossmember correctly, and the frame connectors needed a fair amount of trimming/grinding to fit up against the bottom of the floor pan. I would definately install the pan first, then the connectors....
I'm not sure how much weight is still on the front of your car (not much, as it appears you have it pretty well stripped to a shell), but you may want to install a door and make sure it opens and closes correctly and that the car is not bowing in reverse, and support the very front of the car if you need to....
If you plan on running an emergency brake, you may want to figure out where you're gonna route it before you weld in the connectors. I welded a 1/2" tube thru the connector at an angle for the cable, and it came out pretty nice....

Now I'm thinking that I will install the connectors later.  Even If I tack them in now it doesn't get me much as I still have to finish welding them in, from under the car (yuck),  after the floor is installed.  I do intend to ship the car off for final fitup and paint so maybe I'll just hand the connectors over to the shop and let them install them after they get the doors, hood and fenders installed.

I've seen posts about the cable guide.  Probably do something along that route.

Thanks for the advice folks, at least I have a plan.