550 clamshell latch issue

these are the latches I have.

1st look for contact marks on the edge of the rear fender lining.  More times than not the latch is being hammered open by being hit by the spring plate and no amount of adjustment will fix that.

If that is not the case, there's a modification to the latch receiver that adds a 2nd spring and prevents unwanted releasing.  I know someone has posted pics of this modification here before but I couldn't tell you where.  I can always take some if you can't find them.

Thanks for your reply.  By the rear fender lining, I'm thinking you mean the gap between the clamshell and the body?  If so, that gap is constant with no contact, throughout.  I don't think its a fitment issue but  I could see how that might cause the issue I am having.   If I've misunderstood, please let me know.

I'll look around for that fix, but so far, my searches haven't come up with them.  If you get a chance, a pic or two would be awesome.

Thanks again!

Robbie

Do you have disc brakes, with the calipers facing up?

Do your rear brakes hit the inner fender on the clamshell? This happens and can cause the latch to pop, especially if it's the driver side and you're driving solo.

Sometimes the angle of the latch pin is off just a tiny bit. This can cause all sorts of heartache and steam coming from ears!

The second spring does wonders, but certainly REALLY look hard to see if anything is hitting the clamshell.

Thanks for the input.  

I went back and had a close look at the inner portions of the clamshell and sure enough, there is a spot depicted in the attached picture where the clamshell liner is impacting the rear trailing arm on the passenger side (which is the side with the issue). At rest its not touching, but that area is right over the arm, so any good bump and it pops open the clamshell.

The latch pin/receiver alignment is spot on, both sides.  I also had a close look at that today.  

After the great input here, I am pretty confident I've found the issue.  I'll trim that area and go for a drive, will let you all know if its fixed or not!

Regards and thanks!!

Robbie H

Excellent, Robbie. Trim that thing back and go beat on that Spyder!

I trimmed fiberglass at three locations, over the passenger trailing arm and on both sides, where the inner liner was contacting the tops of the rear calipers.

On the test drive, bumps did not cause a release, but a couple of spirited turns just before pulling in and the passenger side let go. 😞

Examining the areas where i trimmed after the drive showed no evidence of further contact. Maybe i need to add a second spring?  The receivers are riveted in place, but i could probably work on it in situ if i have to. what size springs have you used, and did you place it side by since with the original?

Opposite side of the original spring.  Same size spring.

You have to cut a recess to allow the sparing to fit and then drill 2 tiny holes to attach the spring to the latch as well as to the release mechanism.

To better understand; these latches are VW Bug hood latches and designed to release if your cable breaks, allowing you to get into your hood one more time to change the broken part.  Adding the second spring forces both sides forward, deleting the auto-open feature but making it more secure to prevent accidental opening.

We also weld in a short rod to brace the cable sheath stop and prevent it from bending.

I'll go and take a photo of one now...

awesome, thanks. here is a pic of mine, from below:

yours has the stiffening rod welded in, which is great so you just need to add the 2nd spring.

post a photo of yours from thew top looking straight down.  Your release looks to be too far back and over (or under) adjusted.

we also "dull" the sharp corners of the release if necessary.  just depends on the batch/manufacturer, or how it feels when it closes...

@Robbie Haas

Compare the hole in the middle of the latch in both your photo and Carey’s.  See how there is more latch plate sticking out in the middle hole on Carey’s than yours?   Could it also be that the release cable/wire is too tight on yours and holding the latch partially open all the time?  Maybe that could be adjusted looser on yours to allow the latch to more fully seat and grab the latch pin better (along with adding the second spring).

I may be out of my element, but that sort-of jumped out at me from the photos.

What Gordon said is what I was getting at and why I asked for the top side photo.

However because it releases when he cable breaks it could be too tight or too loose in adjustment.  Remember, when the cable breaks and it is completely "loose" it opens, thus, no tension and it is released and as you add tension it comes into the picture until it gets as far out as it can and then it starts to leave the picture again as it gets even more tension being "opened".  Hope that makes sense.

The stiffening rod! Didn't know that trick...

It does make sense.  From above, the amount of latch plate showing on mine appears similar, perhaps a bit less than yours.  i’ll get a top down pic for you to compare.  

It looks like to add the second spring, i’ll need to remove the receiver?  It’d be awfully fiddly trying to do this from below. Maybe if i remove the battery and its tray.

This is very dependent on camera angle but i spent some time eyeing both of mine and the one that’s letting go (passenger side) definitely doesn’t engage as much. So adjusting the cable seems like a good next step.

Thanks!!

Passenger side

Driver side

Yup, you’re on the right track!

The roads around here are pretty rough. I had a similar thing happen to mine.

This is what I did. https://www.speedsterowners.co...ic/clamshell-latches

I haven't had a problem since.

i’ve looked at the pin alignment, as i saw your post while searching.  Mine seem well aligned.

thanks!

@Robbie Haas posted:

It does make sense.  From above, the amount of latch plate showing on mine appears similar, perhaps a bit less than yours.  i’ll get a top down pic for you to compare.  

It looks like to add the second spring, i’ll need to remove the receiver?  It’d be awfully fiddly trying to do this from below. Maybe if i remove the battery and its tray.

You have to drill out the rivets and remove the receivers to operate on them. No possibility of doing that with them affixed to the car.

When they are out, drill the mount holes a little bigger and set some quarter-twenty rivet-nuts in them, and use button screws in place of the rivets thereafter. That way, taking them out again will be easy.

If adjusting the cable on that side isn’t enough, that’ll be my next project.  Very helpful info, thanks!

it would be a worthwhile project just for the ease of removal alone!

After trimming the clamshell inner lining to avoid any contact with the trailing arms or the rear brake calipers, I renewed the trim that had been damaged and i cleaned, lightly lubed and adjusted the passenger side receiver.

My test drive today was successful, clamshell stayed put despite a moderately bumpy road. So, fixed for now. 🤞🏻

The receiver on that side does not seem as well sprung as in the other side, not sure why, but it’s definitely better after the cleanup and adjustment. 

Thanks to all for great advice and information!