Bikerman883

I have a 1970 olds cutlass supreme and the top is sagging in the back. Is there a way to " tighten it up " I recently purchased the car and believe it has been sitting for about 8 years.

47 Convertible

Convertible tops are a wonder of complexity. In my limited experience top material usually shrinks rather than stretching over an extended time period. So since its sagging and has been sitting for years, the first thing I'd do is check to make sure the mechanism is extending to its full length. If its hydraulic its possible there might have been leak-down and adding fluid and running it up and down a bit to get rid of air bubbles might extend the top to its intended limits. If that's not the case It might be possible to raise the back side of the top a bit with manual adjustments where top mechanism fastens to body but you really need the factory manual to see how its done. Just experimenting doesn't seem like a very good idea given the law of unintended consequences. For example an adjustment that might raise the back of the top might move the top latch-down position out of kilter or raise the top where it doesn't engage along the side windows and you'd have air and/or water leaks. So I think trying mechanical adjustments would be the very last thing I'd resort to if the general fit above windshield and along side windows looks OK.

If the material itself has rotted from UV exposure, stretched or come loose from where it is fastened that's another deal entirely and time for advice from someone who runs a convertible top business.

My convertible experience is limited to a '65 Cutlass I owned years ago and the '47 convertible I currently own so I'm anything but an expert.
Jerry

Bikerman883

Ok, I am going to check the fluid first, is there a level mark? How do I check and fill it? Can transmission fluid be used if low?

Thanks,
Chuck

MDchanic

If the rear curtain is sagging, then it wasn't installed correctly in the first place (unless there is something seriously wrong with the frame, such as a bend, or missing pivot bolts).

The only thing to do is to tighten it up by relocating it at either the trimstick or the main bow, or both.

You need to check the Fisher Body Manual. There is a separate section on removing, replacing, and adjusting the rear curtain.

- Eric

47 Convertible

x2 what Eric said. Get that correct year body manual for convertibles.
As far as checking the top mechanism for fluid, that is way beyond my pay grade but you might start by looking for places around pump, lines and hydraulic cylinders where it could have leaked while in storage or previous use.

Bikerman883

I did notice something odd today, or at least looked odd to me. Where the top meets where the back window is you can put your hand through to the outside, it over laps the back part so water can't get in, but is that suppose to be like that or attached?

MDchanic

The part of the top that holds the window is called the rear curtain.
It is a separate piece from the rest of the top, and can be bought separately.
It is attached on the bottom to the trimstick, which is a part of the top frame that is located below where the top enters the body, and on the top to the main bow, which is the bow that runs over the back seat, where the top transitions from going upward to going frontward.

It is supposed to be tacked to the tacking strip on the main bow about every half an inch or so.
If you can put your hand between the main bow and the rear curtain, that would suggest that it is not tacked every half inch or so, ie: that it wasn't installed correctly, as I said above.

You need to re-install it, as per the FBM, which won't be easy, but you can do it.
There is a decent chance that you may need to replace the tacking strip, and you may also have to remove and re-set the attaching points of the main portion of the top on the main bow, so be prepared for a slow, careful, trial and error job.

- Eric

Bikerman883

Ok I will have to look it up on the Internet. I am waiting on the carb and hopefully takes care of the bogging on acceleration.

Thanks,
Chuck

MDchanic

When you're done looking it up on the internet, be sure to look it up in the Folding Top chapter of the FBM.

- Eric

Bikerman883

I was going to look up the fbm on the Internet, I don't have a manual

m371961

Also note that the rear curtain does not attach to the main top along the sides of the rear window. It is only stretched tight between trimstick at bottom and rear bow at top.

MDchanic

I believe that the only place to do that, short of buying digitized crappy scans on eBay, is to join the nonprofit Automotive History Preservation Society, at WildAboutCars.com, for about $25, which will allow you to access and download a very wide variety of Oldsmobile and other literature and manuals.

- Eric

classicmuscle442

The fill point is in the pump/motor assembly, rubber plug, originally filled with brake fluid, can use trans fluid. Rear curtain is attached between window and rear bow above zipper, should not be able to see thru it or put hand through it.

Tedd Thompson

Always check to see what fluid was used last and refill with that. You can't intermix fluids or bad things will happen.....Tedd

mrolds69

Ok...a few things...if that's your car in the avatar, it most likely doesn't have brake fluid in the top system. You can sometimes see the color through the lines, tranny fluid is red. Early cars DID use brake fluid, I think they stopped using it around the mid-late 60's. That said...could be anything in there, brake fluid, hydraulic fluid, or tranny fluid. It depends if it's been tampered with. Second...you CAN put your hand through from the back window to the inside of the car. The curtain is not stitched to the top there, like Eric said, it just attaches at the top and bottom (on your car). That doesn't mean you can make a fist and push it through, but if you had something thin, you could do that. But...if the back curtain is tight, and the top is tight, there is no space there. The curtain is wider than window opening, so it won't leak if tight. Early cars, like the person that responded said his had a zipper...some of those attach differently with the curtain attached to the top. This is an early installation, but good article on top install. http://www.squidsfabshop.com/bodyw/GTObody.php
This is a later install, but a poor article.http://www.hotrod.com/how-to/paint-b...nvertible-top/

Fun71

If your top mechanism moves up and down without being sluggish, then the fluid level is likely OK.

The fluid level on mine is low and it is very obvious - the top seems to "struggle" to raise at the beginning and then speeds up after it gets near vertical.

Oh yeah, I can't believe no one has said it yet: post some pics!

Bikerman883

mrolds69

Ok...that looks like an inexpensive top and an amateur installation. Inexpensive because no glass curtain. I've seen worse. Might be fixable if you remove the trim stick and re-staple it tighter. That has to be done a few times, it looks like somebody gave up on it. The bigger problem seems like the back curtain or whole top is not centered...like if you look from the trunk lock straight up the back window, it looks off, could be an optical illusion. Maybe just the right side at the bottom came loose.

m371961

With my minimal vert top experience, (but recent) the only way I see to tighten that up would be to remove trim sticks, pull staples and pull back curtain and main top down a quarter to half inch and restaple. Not for the faint at heart. Or take to a top shop. Once it is stapled to the rear bow top it must be tightened at each end by unstapling and re-streching. To remove slack between front and middle bow it would have to be re-done at front header.
Other peeps here have more experience then me. See what they say.

Bikerman883

Thanks for everyone's help, it will have to wait for now, still having an engine issue

droldsmorland

Your top is definitely lose. Another bit of advice is to find a good auto upholstery shop and let them take a look at it. One that does tops, as they do them all day. I have a great shop in my area that is very helpful. If its a simple fix he usually will do it while Im standing there for $20. If its more involved he will tell you whats wrong. I have had several tops put on over the years. I attempted to do my own many many years ago and I fought it. Now I leave it to this guy as Im afraid of screwing up an expensive top. Same for headliners, I let him do it.

Bikerman883

Where are you located?