Door Alignment – Chassis Flex (?)

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  • #235950
    John Simion
    Participant

    @johnsimion

    My VW-based car came to me with a correctly aligned driver’s door and misaligned passenger door.  After going through a repaint, it came back from the body shop with the driver’s door misaligned and the passenger’s door basically okay.  I spent several hours aligning them, and they both open and close beautifully now — but my work now requires another repaint of the doors.  Then last night I was reading about Speedster replicas and came across this chilling quote at http://www.vintagespeedsters.com/faqs/:

    “The speedster replica was born in the 1970???s. Early manufacturers used a shortened VW pan and did not adequately reinforce the body. This led to the infamous ???jack test???. If one were to lift the car with a jack, due to the body flex, the car doors would no longer close properly. Vintage Speedsters engineered a new type of structure starting with our first speedster produced in 1988. 

    Vintage Speedsters uses a custom built, jig welded, 2×4 inch 11-gauge steel frame. An original VW pan is restored, shortened and welded to the new steel skeleton. The rigid new structure retains the original VW pan design and integrates the largest frame possible. All of our custom built speedsters easily pass the ???jack test???.
    Given my experience, it does look like there is a lot of flex in my chassis, and so I am now concerned that all my door alignment work may be for naught the first time I jack up my car … and I already have a need to have all the wheels balanced.  I am starting to feel like I am wasting my time on this car, because I can’t seem to get ahead.  One step forward, two steps back.
    I ran a couple of searches on this site and didn’t find anything relevant, but I don’t want to waste all my alignment work and a repaint, only to discover that my doors are back out of alignment again.  Has anyone else experienced this?  Right now it’s just a plain old VW chassis, seems to be strong and not rusty or anything, but should I take it to a muffler shop (with a full body lift) and have them weld on a bunch of steel reinforcements onto the bottom of the frame before I do anything else?  Or is Vintage Speedsters just BSing to sell a product?
    Or is there a workaround that would let me change wheels and tires without letting the chassis flex and put the doors out of alignment?


    johnsimion2015-11-29 13:01:45

    #266398
    Dale Schumacher
    Participant

    @schu

    John,

    First of all the Speedster uses a shortened pan while ours use the full original pan. In addition if you look underneath you will see that the fiberglass fits to the original pan to add strength. 
    I understand that sometimes the doors do get out of alignment but if you use the rear torsion bars to jack the rear and the front beam for the front you will have no issues.
    I think you need to get the car finished and on the road and start enjoying – then you can do small tweaks as you see them. You have what I call ” builders stress ” and sometimes overthinking your build.
    I know I did it…
    Get it on the road my brother and enjoy. 
    #266399
    KentT
    Participant

    @kentt

    If you floorplan is solid, I don’t think you need to be overly concerned with permanently warping or bending it by jacking it.

    Note however that the original jack point on VWs was on each side of the pan, underneath the rear window, in front of the rear torsion bar. Using that jackpoint would lift both front and rear wheels off the ground at the same time. If the factory jack socket is still on each side of your TDr, I wouldn’t recommend using it because the steel body is no longer above for reinforcement. But, that is a good “balance point” for lifting with a jack. You may want to consider using a floorjack there with a short piece of 2×4 or 2×6 underneath the pan to spread the load. This would function similar to the original design, while not flexing the pan as much as jacking just a corner of the pan up by placing the jack underneath one end of the front or rear torsion bars…

    Meanwhile you can request the tire shop use a lift to lift the entire car for balancing tires, rotating them, etc.KentT2015-11-29 14:09:54

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #266400
    Paul Mossberg
    Keymaster

    @pmossberg

    Ditto everything Dale (schu) wrote.

    The TD replica is a different animal than a speedster.

    I usually jack my TDr as Dale suggests.

    But on occasion I have jacked it up at the “stock” rear jack mounts and have not had a problem.

    Paul Mossberg
    Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
    2005 Intermeccanica Roadster

    If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

    #266401
    John Simion
    Participant

    @johnsimion

    Confusion on my part reigns supreme.  Sorry for my ignorance, but could I get some clarification?

    Schu said, “if you use the rear torsion bars to jack the rear and the front beam for the front you will have no issues.”  I am embarrassed to say that I really can’t identify what are the torsion bars, or where on the torsion bars I would jack.  And that would be moving the jack point farther to the corner, which seemingly would increase the twist to the body … wouldn’t it?

    Kent said, “If the factory jack socket is still on each side of your TDr, I wouldn’t recommend using it because the steel body is no longer above for reinforcement. But, that is a good “balance point” for lifting with a jack. You may want to consider using a floorjack there with a short piece of 2×4 or 2×6 underneath the pan to spread the load.”  I do have the original jack socket, but I’m confused about this post.  DON’T use the jack socket or DO use the jack socket?  I gather that you mean to put wood under the jack socket, but then the question is whether the wood goes lengthwise along the car or crosswise?

    And how would you fit the wood under the metal rib under the original jack socket?  Cut a notch in it, but that would weaken the wood quite a bit, I would think.

    Instead, could I maybe put a 2×6 running along the side of the car and center the jack under it so as to spread the load evenly along the entire side of the car evenly (???).  Or (since that would be moving the jack point forward) would that then introduce even more flexing?


    johnsimion2015-11-29 17:52:55

    #266402
    edward ericson
    Participant

    @edsnova

    Bottom line: try not to worry too much.

    My experience with a somewhat rusty pan is that the doors more or less fit OK. The passenger side is a bit “sticky” if left unused for a time.
    The torsion housings are as follows: Front: the two big (2 1/4 inch? diameter) tubes, one atop the other, separated by a few inches of space, which run crosswise behind your front bumper, roughly under your grill. On each end of each tube is an L-shaped trailing arm that leads to the brake drums or discs behind your wheels. Can’t miss this feature.
    Rear: about 16 inches in front of the rear wheels’ centerline is another big round tube running horizontal under and just behind your seats. On each end of this tube is a four-bolt cap with a smaller-diameter pipe-like thing potruding from it into or just under the very rear of your running boards. Your rear trailing arms attach to two thick metal plates that attach near the ends of the main tube. 
    If you put a jack under the car and jack it up at any point along either torsion bar, the frame/pan will not deform. 
    You will likely see other metal square tubing under the rear of your car. On mine there is a crossmember and subframe clamped to the “frame horns”–those are the two giant rhino horns of metal that the engine and transmission bolts to. When working out back I jack both rear wheels up by lifting at this crossmember, then put jack stands under each side of the torsion housing. In front: jack the torsion housing and then jack stands on each side. easy.
    I have also used the “jack point” to lift one side of the car at a time. As Kent suggests, a bit of dimensional lumber seems to help here. I’ve used a less-than-2-foot piece of 2×6 running along the edge of the car lengthwise. 
    Again, again, though: your door issue is less likely to be frame related than you suppose. Examine it carefully and report back.
    #266403
    John Simion
    Participant

    @johnsimion

    Thanks for the clarification, Edsnova.  After re-reading, I crawled under the car and looked around and think I’ve got it … particularly when I found this diagram.  The diagram makes more clear to boneheaded me as to why (2) and (3) wouldn’t bend the pan.  Dunno if I want to take any chances with the regular jack points, however.  Looks like I need to visit Pep Boys tomorrow.  I need to get a scissors or floor jack, some wheel chocks, and some lumber, then I think I’ll take the wheels off myself to have them balanced.  Looks like my best bet for doing that would be to use points (1) (2), and (3).

    #266404
    Paul Mossberg
    Keymaster

    @pmossberg

    Yes, you need a floor jack. Scissor jack is the second choice.

    Safest jack points are at 1 and 3

    2 shows the stock jack points, but you won’t find the “socket” shown in the diagram. That got cut off.

    When we write to lift the car at the rear torsion bars (3 in the diagram), here’s what we mean. Lift it where the jack stands are shown in this picture. The example is a Type 3, but suspension is similar. Even more specifically, I put the jack saddle under the lower edge of the swing arm, where it meets the torsion tube. That leaves room for the torsion tube to rest on the jack stands.

    PMOSSBERG2015-11-29 23:47:40

    Paul Mossberg
    Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
    2005 Intermeccanica Roadster

    If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

    #266405
    KentT
    Participant

    @kentt

    The factory jack sockets are those things sticking out from the side near your noted #2 and #3 on the drawing. I would not recommend using those sockets, but those are good lift points if you put a short piece of lumber along the edge of metal floor pan there. You can lift the whole side of the car from there.

    Sorry if I wasn’t clear…KentT2015-11-29 23:48:54

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #266406
    Paul Mossberg
    Keymaster

    @pmossberg

    One additional comment…

    We are not really talking about “chassis flex” here. It’s more like “body flex.”

    You can cut the floor pans away from a VW chassis and she’ll sit there as level as always.

    The problem is lifting the car at the stock jack points. The stock pans have the benefit of an all steel body bolted on. That adds a lot of strength, so you are able to safely lift the car without the body flexing.

    We bolt a fiberglass body to the same mounting points, but that’s simply not as strong as the steel.

    The risk is that lifting a TDr at the stock points will cause the outer corner of the pan to flex, and with it the entire body will flex.

    Paul Mossberg
    Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
    2005 Intermeccanica Roadster

    If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

    #266407
    scubasteve
    Participant

    @scubasteve

    This is why I LOVE this site!
    I come to look for ONE thing and find out much more than I ever thought.
    I figured I was lifting my car from the correct points, since they seemed to be the most solid, but didn’t know that #’s 2&3 are the TORSION BARS! (I knew WHAT torsion bar suspension was and HOW it worked, but never actually SAW it!)
     My fourth grade teacher used to say, “Learn something new EVERY DAY.” So she’s happy with me!

    Amor Conquista Todo

    #266408
    John Simion
    Participant

    @johnsimion

    The only thing bad about this site is discovering one’s own ignorance.
    These guys are incredibly helpful. Thanks!!!

    #266409
    Dbanta
    Participant

    @dbanta

    I found these. http://www.evhcompany.com/ just look for floor pan stiffener. These guys make some neat stuff.
    PMOSSBERG2015-12-01 23:39:42

    In wine there is truth, in water health.

    #266410
    John Simion
    Participant

    @johnsimion

    I like that floor pan stiffener but it looks about impossible to install to my car, now that it is nearly complete.

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