'69 Front Frame Rail Installation

Discussion in 'Classic Mustang Specific Tech' started by JeremiahJohnson, Mar 16, 2014.

  1. Hello fellow mustang enthusiasts,

    I have used various mustang forums in the past to answer lots of my mustang build questions, but I have finally come up with a question that I cannot find the answer to in an existing thread. I have a 69 Sportsroof and I have replaced the entire floor along with toe boards, fire wall and frame rails. I am at the point now where I am ready to reattach the front frame rails to the inner floor supports. The front frame rail assembly is complete with shock towers, front fender aprons, and radiator support. The only pieces not installed yet on the front frame assembly are the rear fender aprons (I thought these would be easier to do last).

    My question is how can I make my car whole again while ensuring that the car will be square and properly aligned? I am thinking about the wheel alignment as well as the fender/door/hood alignment. I would appreciate any suggestions or experience you can share.
  2. Some pics of just where you are at in the install will help.
  3. First of all make sure the car is level front to back and side to side .Put it up on jack stands to make it solid. Once you get to this point i can give you measurements from my 69.
  4. Here are some pictures of the two pieces I am trying to put together. They are the best I have right now. I can get some better ones later. 007.JPG 003 (6).JPG
  5. Very good ,this will not be a problem. Like i said though level the body front to back using the lower door sill .and also through the door openings First .You should be able to have the front clip welded in place in just a couple of hours. Do you have an export brace and a Montycarlo bar? They will help a lot but it can be done without. It will take me a little bit to get the measurements and i will take pics as well .
  6. I have some measurements . I think you will have to start with the rear inner aprons and attack them to the front clip ,that way you can put the front clip in in one piece .
    Your apron will clamp over the spring tower as normal your first measurement will be to the first fender mounting hole in the hinge apron ,from the front of the oval hole to the front of the radiator support is 35 1/4 inch this will keep your fender bolts correct . _MG_4381.JPG next measure up from the top of the frame rail to the end of the flat spot that the hinge will fold into on the apron,farthest point back and that will be 18 5/8 inches high. that is the indent you can see in the top pic. once you have this you can set the front clip in place . The frame rails will slide into the floor supports and the inner apron will slip under the two brackets already on your cowl. now you are ready for these measurements ,From the front of the radiator support measure back to the front of the square hole for the fender mounting bolt in the cowl brace it will be 41 5/8 inches to the front of this hole ,this will keep the fender mounting holes correct and set the length of the front clip at the same time. _MG_4380.JPG I would screw everything together first encase you need to make any adjustment. now for the frame rail length .I measured from the front of the torque box to the front of the front crosmember, you can measure from the flat spot on the rocker to the crossmember it will be 41 3/4, not the tab but the face of the crossmember . _MG_4382.JPG
    To check everything ,with the car level at the door sills ,the frame rail should be level as well at the ledge where the bumper brackets bolt on. I tried the level on top of the front of the frame rail but the top runs down hill slightly ,the ledge will show level _MG_4387.JPG
    _MG_4388.JPG you will also want to put a level across the front crossmember as well .I hope this will help ,if you have any questions just ask. Jim

    Attached Files:

    #6 horse sence, Mar 16, 2014
    Last edited: Mar 16, 2014
  7. Wow, Jim this is awesome. This is just what I was looking for. Thank you. Like you said I will screw everything together first then I may even hang a door and fender just to see how the gaps line up. I have the car outside on my driveway and since the weather in central Illinois is not cooperating, I probably won't get to it for maybe a week or so. But that will give me time to sand blast the inside of the frame rails and weld on the outer panels of the frame rails. Thanks again, I'm sure I'll have more questions for you soon.
    horse sence likes this.
  8. Jim,
    I do have an export brace and a monte carlo bar. They are both Scott Drake brand so I would assume they are accurate. I will bolt them up too when I get everything in place and I hope they will fit well. Actually, now that I think about it, I did fit the export brace before I cut the car apart and I think I remember the export brace would not sit flat on top of the new shock towers. Not sure what to think about that.... The bolts in the top of the shock tower should pull them down though.

    For the measurement of 41 3/4" from the torque box to the front crossmember, should I add the thickness of the torque box panels to this measurement since I do not have any torque boxes in place? I am not sure if the flat spot on the rocker is reliable since it was part of the dynacorn floor. I'll take some measurements tomorrow to see if the two sides are at least even.
  9. Ye i would allow for the thickness of the torque box ,it will only be about a 1/32 of an inch though . i will try to get a measurement from the under side for the front frame rails some time to day just to be sure , From the rear of the car to the front .
    I have a ford export brace i keep for aligning front metal ,it keeps every thing in line after measureing .The montycarlo bar keeps side to side in line .I even bolt the under brace back in the frame rails once the front clip is in place to keep the frame rails the correct distant apart .
  10. I got a measurement from under the car ,it is the hole in the rear frame rail just behind where the rear leaf bolts . This is where the floor pan was attached to the assembly skid . From the front of the hole to the front of the front crossmember it is 112 inches exactly .I measured both sides and they are the same .
    _MG_4390.JPG _MG_4391.JPG
  11. Thats great, Jim. Thank you. I appreciate you climbing under there to get these measurements for me. Now, I just hope that dynacorn put those assembly skid holes in the same place. (I installed a complete dynacorn floor.) I think with these measurements coupled with the fender apron measurement and the export brace and monte carlo bar, I should be able to get this done.
  12. So, I tried attaching the front end this weekend but quickly realized that the inner floor supports coming off the dynacorn floor pan were about 3/4" too narrow. I couldn't get the frame rails to line up. The only way I saw to solve this was to cut them off and weld on new ones in the correct location. I have one support cut off, the second will come off soon. But this got me to wondering about the height of the supports as well. Since the supports weld right to the floor pan itself, I measured the distance from the floor pan to the top of the rocker, near the kick panel, and got a difference of 1/4" from drivers side to passenger side.

    Jim- I was hoping you wouldn't mind taking a few more measurements?? Could you possibly measure what the distance should be from the floor pan to the top of the rocker? Or some place on the kick panel or cowl, since my dynacorn inner rocker may not match the original outer rocker perfectly? Thanks, Jim.
  13. These pics may be hard to make out ,my camera doesn't like me anymore.
    from the top of the frame rail in the engine compartment up to the lip on the cowl is 17 1/4 inches ,at that round area that sticks out on the cowl lip on both sides. _MG_4493.JPG _MG_4494.JPG
    From the top of the floor pan to the top of the lip of the rocker is 4 3/4
  14. This is great, Jim. Thanks!
  15. Yes, this I great. Just the info I was needing also. I was doing a quick string and jackstand alignment check on my 69 coupe and discovered that the drivers front wheel is 1 inch closer in towards the engine than the right side. Pretty sure this isn't normal.:scratch:
  16. If you're measuring your wheels for alignment, try doing it again with the wheels on the ground. You may get a slightly different measurement when the suspension compressed.
  17. It was on the ground. I'm gonna measure it out with his numbers when I get home and see what I come up with. Just hope its nothing major.
  18. Take the wheels off and measure to the inside of the towers from your string .
    your upper A arm shafts may be worn out ,you would do better to place a straight edge down the rockers and measure from that though. it is possible the tower is leaning in on that side.
  19. The a arms have all new bushings in them. But, I did have a heck if a time getting a strut brace to go on one time and just thought it wasnt a quality part. I'll defiantly check out the shock tower. That would make sense. They have a tendency to collapse in right?
  20. They will actually break off . All you would have to do is run into a curb to bend it or break it . My 68 convert had the whole piece that the motor mounts to break off and let the motor drop . That is how i bought it .