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CONVERTABLE TOP

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J

JPITCHP

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DOES ANYONE OUT THERE KNOW HOW TO INSTALL A CONVERTABLE TOP ON A 1976 MGB. I PURCHASED A NEW TOP FOR MY RAILS AND IT CAME WITH NO INSTRUCTIONS. THE BACK AND SIDES ARE QUITE SELF EXPLANITARY, BUT THE FRONT IS GOT ME GUESSING. PLEASE HELP...............

THANKS, PAUL PITCHER
 
The front of the top is riveted onto the head rail underneath the weather stripping. the weather stripping is heald onto the header rail by a C shaped retainer rail. Carfully remove the weather stripping from the retainer rail and you will see the rivets. The shape of the retainer rail holds the weather sripping in place and should just pull out. But do this carefully so you don't tear it as it's a foam rubber type of material (if you want to re-use it). I would suggest replacing this, as you want a good seal (and I did tear mine as the person who installed my previous top glued the ends of the stripping to the retainer). So.... Here is a rundown of the installation, first, material Needed:
Drill with small drill bit 1/8" or so
Pop rivet Gun
15 smaller sized rivets
White china marker
Philips screwdriver
a couple small spring clamps
Small nut or spacer
A new top, and a new head rail rubber seal (wheather stripping)
Contact cement
a couple cheap paint brushes
an Awl or a knife
Scissors
Patience

First lay the new top over the old top to guage the fit. This will show you how much extra material is at the front of the top. If all looks well, set the new top aside, out in the sun, and remove the old top at the back of the car. With the header rail attached to the wind sheild, remove the 6 screws that fasten the frame to the header rail. Use a #3 bit so as not to strip out the screws (a battery drill makes it easier).
Unfasten the header rail from the windsheild and take the old top over to a soft work area (I did mine in the lawn). Remove the metal bar from the back of the old top and set it aside (note the orientation of the bar). Carefully remove the weather stripping seal from the head rail to expose the rivets holding the seal retainer and the top to the head rail. Remove 1 philips (#2) from each end of the head rail. These screws hold the side of the top to the head rail. Put these in a safe place. Using your drill and drill bit, carefully drill out all of the rivets. Don't use too big of a bit as you don't want to make the holes bigger. The old rivets will drop into the head rail and unfortunately there is no way to get them out. Set the weather seal retainer aside, and peel the old top off of the head rail. It should be cemented to it. I had bought a new seal retainer from Victoria British, but used my old one. The holes in the new on didn't line up at all and it was shaped incorrectly. The new seal, however, fit fine.
Now, attach the head rail to the windsheild by the 2 headrail clamps on the rail. Put the frame up but don't attach it to the head rail. Inset the metal bar into the new top with the correct orientation. and fasten the new top to the back of the car using the bar and all the 'lift the dots'. Carefully drape the new top over the loose frame. The very back support will be loose, just position it all the way down towards the back of the car and out of the way. We'll deal with it later. Pull and stretch the top towards the front of the car. DO THIS IN THE SUN ON A WARM DAY. Let the extra material hang over the windsheild. Keep pulling and streatching for a bit. Once you feel it's streached as much as it can, center the top on the car (and head rail) and use the clamps to clamp the top to the head rail at the front of the wind sheild. There should be enough space for the clamp and the top between the head rail and the windsheild because you don't have the seal in place yet. Clamp it at both ends of the head rail.
Now take a break, while the top streaches a bit.
After your break go out, remove the clamps, and streatch the top some more. Streach it forward and side to side. Then re-clamp to the head rail. Now, get inside the car and see if the snaps at the front of the top on the inside will snap into their mates on the windsheild. If they do Good. If they don't, Keep streatching till they will.
Once the snaps are in place, check to make sure the top is centered and appers to be a good fit. Re-adjust if necessary. Once the fit looks good, you need to mark the head rail position on the underside of the top (from inside the car). Scribe a line as close as possible to the head rail on the top to mark where the head rail is positioned front to back on the top. Next make 3 marks on the head rail, one toward each end and one in the center. Make marks on the top that line up with these to mark the left to right position of the top on the head rail.
Remove the top and the headrail and take them into the yard, again, in the sun. Spread the top out with your marks facing up. Lay the head rail on the top in the correct orientation, and align it with the scribe mark and the left to right marks. Bring the sides of the top up and over the head rail and clamp it in place again. Make sure the fit is good and get all of your marks lined up. This takes a bit of fussing and streatching. Its also a good idea to just cover the scribe mark with the head rail. This will insure that the top is a tight fit. But, not too much as you don't really want it so tight that you can't get the top up =P. just barely cover the line. Once you have it where it should be, Screw the tags at the side of the top with the screws you removed from the old tags on the old top. Use an awl, or a pocket knife to cut small holes in the top where the rivets go. You may need to do a little streatching as you do this. Take your time, and make sure everything is lined up correctly with each hole you do. Or, alternativley, you can punch one hole at one end, and rivet the seal retainer to that end and then progesively work your way down. Just work carefully and rivet the seal retainer to the head rail with the top between the head rail and the seal retainer. This is trickey as the head of the pop rivet gun won't go down all the way into the seal retainer. The solution is to fit a rivet into place and then a spacer like a small nut over the rivet. The nut should fit into the seal retainer and the head of the gun should be able to touch the nut. This will let you rivet without bending the seal reatainer out of shape.
Once all the rivets are in place you need to contact cement the top to the head rail. Just lift the headrail onto your lap and push the top a bit away from it. Brush cement on both the rail and the top, being carefull not to get cement on the top past the point where the rail is. Hold the top away from the rail for a couple minutes to get the cement tacky, then glue together.
Fit the weather seal into the retainer. Start at one end, inserting onside of the seal into the retainer and use a flat head screw driver to position the other side of the deal in place. Carefully work you way across the head rail. When using a new seal, the ends may want to come out of the retainer. A bit of contact cement will fix this.
Now, it's time to fit the top to the car. Again, fasten the top to the back of the car. This time only using the metal bar in the 2 chrome clips, and make sure that the loose frame support at the back of the frame is forward this time. Carefull drape the top over the frame and lay the head rail at the windsheild. Attach the head rail to the frame with the 6 #3 screws. Clamp the headrail to the windsheild with the 2 headclamps. If you used a new seal, this can be difficult as it is not yet compressed. A little help from someone outside the car can help, as can a bit of lithium grease on the part of the clamp thats on the windsheild. Snap the snaps to the windsheild. Insert the hooks at the front part of the back of the top, and then snap in the 'lift a dots' or at least as many as you can. One on each side of my top don't line up correctly. I used one of the cheaper tops. Position the loose frame rail into the correct position (at the 2 flaps of material). Now, keep the top up for a couple sunny days to let it streach out and for the seal to compress (I left mine up for a week). If you couldn't get all the 'lift a dots' in place, try them again every day.
After a cople days, unfasten the head rail, and bring the top back a bit so it's loose. Cement the cloth flaps to the loose frame rail, one at a time. Once this is dry you are done. Enjoy =)

-Doug
 
good gravy... now THAT'S a post on how to do something!
 
Huge thanks to Doug for these instructions. I have a '75 that needed a new top. After reading these, I was inspired to do it myself (even after others had tried to talk me out of it). I bought one made by EZ On Tops from Ebay seller (topsonline.com) for only $169.50 plus $15 shipping. I had it on in one day (stretching it is what takes the most time). Only thing that I did differently was the riveting. Instead of starting at one end and working across, I started at the middle and worked alternately out to each end. This allowed me to make sure my end marks lined up evenly.

Thanks, Doug for helping an amateur save a few hundred bucks! /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/cheers.gif
 
Wow! My 76B won't get it's top 'til next year (he says hopefully....), but this is going stright into my "shop book" today. Thanks a million, Doug. If my LBC ever makes it out to Indianapolis, the beers are on me! /ubbthreads/images/graemlins/cheers.gif
 
Glad it helped =) It's really not that hard, just takes patience. Also I read a post or something somewhere where a person used screws in place of the rivets. Would have to be the right sized screw, but it would easily be undoable if for some reason things didn't line up.

-D.
 
A lot of the B tops I've replaced have already had the rivets drilled out and replaced with screws. IIRC, Robbins (and mebbe Amco) used to come WITH some nice flathead phillips ones, just right for the job: allowed the rubber seal to be refitted without interference and no need to drill out the 1/8" holes any larger. don't know if others included screws.
 
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