clamshell tailgate assembly

Hey guys,

I want to show the tailgate workings as I reattach the tailgate to the roller mounts and regulator arm.

Hopefully, this will show how simple this tailgate assembly really is, and take some of the mystery out of how it works. :2_thumbs_up_-_anima


This first pic shows the regulator assembly with motor.



This is the regulator mounting arm.



The tailgate is ready to be attached.



This is the LH roller mount. It is attached to a crossbar over to the RH roller mount. A nylon roller rides in a curved track mounted in the tailgate stowage area.
Three 7/16 bolts attach each roller mount into each lower corner of the tailgate.







Once all the bolts are in place, but not tightened, pivot the top of the tailgate upward to meet up with the regulator arm. Three large phillips screws attach it to the inside of the tailgate...tighten just fingertight.



Now the tailgate can be adjusted for fit.









This shows the striker and locator...I had this part out for cleaning. I also adjusts, and will affect alignment.



Now the tailgate is in place and it lines up pretty nicely. Goes ahead and make sure all nine bolts are now tight.







I will show the lowering and raising of the tailgate in the next post.

David

 

This post will show the lowering of the tailgate as it glides down into it's stowage area.











Now, raising the tailgate.











The RH side as the tailgate is lowered.











My next post will show some of the problem areas of this system.

David

 

These are some of the potential problem areas of the clamshell tailgate system.

The bottom mounting point of the tailgate panel on the LH side is prone to stress cracks and tearing. Rust can form in the area when dirt and leaves get into the panel, and then trap moisture.

The LH side of the tailgate is under stress when the regulator arm pushes and pulls the tailgate.
If the tracks are not lubricated, the stress is higher.
Once this mounting point tears, the tailgate is out of alignment, and the regulator and rollers have to struggle to open and close the gate, causing more stress to the entire assembly.



My tailgate was broken in this area, and I had to insert new steel, and weld it up.

Easy fix...and without it, I would have never been able to align my tailgate.
It was very noisy and sluggish in operation, no matter how much I tried to adjust it.



Notice the LH roller mounting shaft is at an angle instead of parallel to the bottom edge of the tailgate.



Not the best pic to show this, but see how the shaft is parallel to the bottom edge...it is not bound up and struggling anymore. That tailgate lines up.

I had no idea this mounting area was torn until I removed the tailgate.



RH mounting point...it was fine.



The tracks should be cleaned of old dried lubrication and dirt, and relubricated. The cleaner everything is, the better.



The LH roller mount actually moves on this shaft, allowing lateral movement. This is also a point that should be lightly lubricated.







Hope this helps!

David

 

Sheesh, with that, you could almost throw the manual away. And I don't own one!

How are you going to get that long nameplate on the tailgate?...

"Le Buick d'Elegance Plus"

 

David, this is awesome! In addition to the time and work you're putting into your resto project, lemme be among the first to thank you for the time and work you put into photographing and describing every step of what you learned along the way!

*knock on wood*, my tailgate and rear window are working fine, but I'm haunted by the thought that I should perform some PM (preventative maintenance) on them. My first step is to locate replacement rubber seals for the window tracks before I start taking anything apart. But here's a question for you about the tailgate: Is it necessary to remove the rear bumper to adequately clean and re-lube the tailgate tracks?

 

I would have to say YES. There are two access plates under the stowage compartment, visable in my pics, but these are still very small, and it is hard to do much of anything worthwhile through them.

Removing the bumper system is really the only way to fully see and clean all of the tracks and remove any debris.

It sounds major work, but you will be glad you did it this way.

David

 

Okay, I was "afraid" of that only because it means I might have to hire someone to help me do it. The posts to which my bumper is attached appears quite rusty, so I may need the help of a body shop... which I was thinking of visiting anyway to address some body rust in the two rear quarter panels. Yesterday my mechanic gave me a high recommendation on a local "coachworks" place. Gotta save up some more money first, but this is next on my list.

Thanks David.

 

Hey Glide,

Check out this thread on rusty bolt solutions. It might just save you some money and hassle!

http://www.stationwagonforums.com/forums/showthread.php?t=7486&highlight=acetone

Buy some simple ingredients, mix them in a spray bottle, spray some on the rusty bolts over the next few weeks, and you will have that pesky bumper off! :2_thumbs_up_-_anima

David

 

this post will be visited in the next few decades on an almost regular base by clamshell owners and mechanics from all over the world... this is again another example and true candidate for a tech data base here

 

Thanks Rob. All over the world? For decades?

Maybe when I get this thing all painted and looking nice up in the nooks and crannies, I will shoot another series of pics for a better looking tech how-to thread.
Kind of embarrassed to show the poor thing to the world without any make-up on her...warts and all!

David

 

Yep, I second that emotion. We've had so many enquiries about Clamshell tailgates, and lots of solutions offered, but this and your documents sort of nail it down. Other than holding the wrenches for the next guy, there just hasn't been a better picumentary!

Stef! Oh. Stef!!!

 

Hi David,
well you have just gone all over the world. I am in Australia, and have a 74 Chev Caprice Estate wagon that I need to restore. I am just tackling the tailgate. The motor that runs the tailgate has been removed as well as the window regulator (I need to source them, but I will do that on another post).
I need to remove the tailgate and David your images have been fantastic helping me understand how it works. I just have 2 more questions;
1. I see that you have removed the internal torsion bar. Is that something you have to do first? I have a very generic type manual that talks about putting bolts in the runners to keep everything in place..???
2. On the RH side where the striker and locator is, do I need to disengage that somehow before the tailgate will come out?

 

Hi David,
your instructions have definitely gone world wide. I am in Australia and about to rebuild a 74 Caprice Estate 8 seater wagon, and information on these over here are nil, until I found this great forum.
I am about to take the tailgate off for repairs, and I noticed from your images that you had taken off the thinner torsion bar that runs across the inside of the car (from the winder assembly). Does this make removal easier, as all the other instructions I have seen talk about placing a bolt in the channel, which I presume stops the runners flipping ut the top when the tailgate is taken off?
Is it a hard job to remove that inside torsion bar?

I waould also like to ask (maybe in another thread) how I go about taking the cable out that runs the tailgate. Mine is very dirty and I want to fully clean it before I put everyhthing back together.

Paul

 

Hi Paul, welcome! Glad you found us!

It makes me smile to know that you are finding my photo guide useful in working on your clamshell tailgate.

I removed my torsion bar when I was going through the system, because water had collected in it's mounting channel, creating a trough, and rusting the torsion bar. I soaked the bar in metal conditioner, and then coated it in Por-15.

I would remove the torsion bar when removing the tailgate. It frees everything up so you are not fighting against it's subtle pressure. Plus, unless your wagon has stayed amazingly dry in this area, it will probably need attention in this area.

CORRECTION: I was incorrect in advising removal of the torsion bar when removing the tailgate. It is not necessary. The torsion bar assists the regulator with lifting the tailgate for closing, for both electric and manual operation.

Removal of the tailgate is accomplished solely by the removal of the three large screws attaching the regulator arm to the gate, and the six roller mount bolts-three each side- on the bottom.

However, it is still advisable to check the torsion bar and it's recessed housing for corrosion.

When removing the tailgate, putting a bolt or small tool in the keyhole-shaped holes in both roller tracks is advisable. Doing this will help you from having to hold the gate up after removing the three bolts that attach the regulator arm to the tailgate. The tailgate will want to roll down on the tracks as soon as the upper arm is unbolted, and these will prevent the rollers from moving downward more than a few inches.

Make sure you have towels or something to perhaps protect the outer finish and trim from possible damage, if you have to stop in the middle of removal or installation, say, to retrieve a tool, etc. Gloves are helpful, too.

Take pics, and show us what you are doing! And ask more questions! Questions are good!

David

 

One of my favorite tailgates of all the Long Roof world and fully explained.
Loved it and enjoyed every word.

Thank you! :You_Rock_Emoticon: