Saab Central - Technical Help
Classic Saab 900: Door repair and maintenance
This article kindly written and supplied by Fred Lane
Mind the doors, and keep your hinges well oiled!
I, almost accidentally, bought a second Classic 900 last year. This gave me the chance to tackle some of the 'little' DIY jobs on my 3 door 91 white LPT Aero without any rush to put it all back together for Monday morning. The first job was to sort out the 'dropped' door hinges, but while the doors were off I found they needed a few other bits of preventative maintenance. Remember this is nearly a ten year old car.
Hinges, oil and wear
The front door hinges are substantial and could last forever if kept well oiled. Preventative maintenance involves applying engine oil to the cut out in the head of the hinge pins. The top hinge pin is accessible with the bonnet open. The lower pin is oiled through the oval hole in the door pillar, which is just below the rubber bellows which carries the wiring loom into the door. On the drivers side you should move the ventilation vacuum reservoir out of the way to see what you are oiling. The cut out in the head of the hinge pin joins a spiral groove that leads the oil into the hinge flap.
The photograph of the two new hinge pins shows this spiral, and also some serration's behind the head of the hinge pin. These serration's bite into the top fixed plate of the hinge, and the hinge flap moves around this fixed pin. The hinge pin should not rotate in the hinge body. If this oiling is neglected the pin seizes in the hinge flap, the pin lifts slightly in the body and the serration's lose their grip on the top plate. The pin now rotates in the hinge body, wearing down the serration's, and a small area of metal is carrying the entire load. The hinge wears very quickly, the door closes badly and chatters at the front edge. Poking my nose into other people's doors reveals that this is not an uncommon problem. Resuming oiling doesn't help much, unless you can free the pin, push it back down and get the serration's to grip again. New hinge pins with fresh sharp serration's are about £5 each.
New hinges are £100 plus, so if things are really bad visit the breaker. Look for an oily set of hinges with the heads of the pins tight to the body. I chose to fit new pins. The old pins took a combination of releasing oil, heat, and lack of patience before they could be persuaded to slide out of the hinge flaps. The spiral grooves were clogged with dirt which had prevented any oil reaching the parts that matter. When reassembling I shimmed the hinge body with washers to prevent undue up and down movement of the flap, but this may have been unnecessary. So far (4 months) the pins have stayed down tight, but I'm watching.
Removing the door
I found it easier to take the doors off by undoing the bolts which fasten the door to the hinge. This allowed me to slide the door carefully away from the shiny paint work balanced on a well padded trolley jack. Releasing the hinge from the pillar first, as per the book, seemed to require too much juggling with the heavy door near the car, which made me nervous. The book method probably preserves hinge alignment and requires less adjustments on refitting, but I was taking the hinges off anyway.
The door wiring loom is disconnected from the car at the connectors tie wrapped alongside the top hinge. Depending how much electric you've got in the doors, you may find the connectors won't thread through the hole in the door pillar. The four pin connector for the electric mirrors certainly won't. After I'd stripped the loom from the door in an attempt to thread it all back the other way (which also doesn't fit), I found that the connector blocks can be dismantled. The grey outer shell can be removed from the individual connectors by clicking back the rear sides of the shell. This exposes individual bullet connectors for each wire which pass through the door and body holes easily. Make a note of the wire positions first, the colour code is not always the same on each side of car or each side of the connector. This is also an easier way of separating these connectors in general, particularly the exposed ones that fill with dirt. Just pull the outer bodies back from both halves and you can separate each wire in turn.
Adjusting the door
Adjusting the door fit took time, my other 900 doors close really sweetly so I copied the fit from these. Adjust the door on the hinge flaps to get the gaps correct. I aimed at a 5 mm gap at base of windscreen and bonnet and the rest of the gaps larger and paralleled. Adjust the hinge position on the body to keep the door flush with the front wing. Adjust striker plate to keep it flush with rear wing/door. Keep the weight of the door on the jack when the hinges are loose.
The rubber door seal material seems to have a memory. So the well adjusted door was hard to close initially, but settled down after being closed overnight. I'd cleaned up the door seals and other rubber parts on a low temperature cycle and soap in the washing machine (you are sworn to secrecy on this point). This made the door seal very fresh and plump which is maybe why it was hard to squash. When refitting the door seal note the odd spots of mastic used at changes of section near the top of door.
Treat the rust
The factory was not as good as it should have been at cleaning up the quick tack welds that fit some parts together (for example tailgate hinges to tailgate). The messy welds don't take paint well. So, on the doors, you will find some rust spots:
- where the window channel is attached to the door, both inside the door, behind the window trim, and behind the door mirror.
- at the lowest point of the window channels;
- where the hinge brackets are welded to the front edge of the door.
However the main door rust trap is the row of small holes that accept the plastic clips that attach the door seal along the lower edge of the door. This area collects grit and moisture and door movement grinds the grit through the paint to let the rust start. Get the door seal off to clean all this up. One suggestion (from Simon) is to use double sided trim tape instead of the plastic clips to refit this lower section of seal. This should keep water and dirt away from the holes. Also check behind the rubber flap that seals the very bottom edge of the door. This area is very well painted initially, but you may need to drill the heads off the pop rivets to remove the strip and apply more. Use the big headed soft rivets with backing washers to refit. Longer rivets are required on Aero's to secure the skirts. Finish off with a coat of rustproofer inside the door.
If you're fussy, paint the door hinge face. I've only ever seen these finished in undercoat and a bit of overspray. On the white cars it looks better with some gloss coat and it should help resist the rust.
Aero skirt drains
On the Aero, add a drain hole at the rear end of the skirt. Mine collected water in the door skirts, which poured out of the front drain hole when the door was opened, even long after the rain had stopped. The second drain hole prevents this interesting display of territory marking. This drilling is easy with the skirt off the door (slides to rear of car when the rivets are removed) but can be done in situ. There's 35 mm of headroom between skirt and door bottom, so you shouldn't drill through the door as well.
Check the window glass for the beginnings of the vertical scratch problem. This seems to attack 2 and 3-door cars when the trim securing clips bite through the lower outer window weather-strip and start cutting 10 mm wide tramlines on the outer surface of the glass as it winds down. Early warnings are very clean strips after winding down a dirty window, you can also see the mark the horizontal edge of the clip is making in the felt face of the weather strip. The fix is to grind a little of the clip away, there is a good description of what's required on the townsend website (townsendimports.com) but it's just a matter of making sure the clip presents a flat face to the back of the weather-strip. The sketch shows, in section, how the 'W' clip holds the weather strip and the trim strip to the door. Removing these clips requires some care. First remove the door trim, then the 'inside' felt strip which is on it's own set of clips, then the glass (2 screws to winder mechanism and top back corner of glass up to outside of door first). Remove the mirror by popping the pin from the black plastic trim rivet to remove triangle of trim and to reveal the mirror securing screws. You can now see all the clips fastening the trim strip and can lever it up evenly, complete with the weather-strip, without risk of bending. Take care unclipping the weather-strip from the trim strip if it's not already damaged, old weather-strips are fragile as the internal metal reinforcement rusts near the ends. Grind the offending lip from the clips and reassemble. New rubber/felt weather-strip is available from the Saab dealer, about £15. Sealing the ends of this strip with mastic might prevent it rusting like the old one. Clean up and re-tape where the clips bite the door edge (99's go in holes here!). I've never failed to find the pin from the mirror trim rivet in the bottom of the door (sometimes more than one).
Window winder mechanism
Free up and grease the electric window winder mechanism. The joints in the mechanism get stiff and dry, which places a high load on the quadrant gear and motor. The window will run up slowly and eventually the motor or quadrant teeth give up. Stafford Swedish Cars (www.ldb.co.uk/swedishcars.htm) sell a quadrant gear kit, and motors can be overhauled ( see Driver issue 2000/3 page 20), but prevention is better than cure. Remove the assembly from door, then the motor from the assembly. If the mechanism is free, the spring will force the mechanism to the up position when the motor is removed. Keep applying release oil to the four main pivot joints and working it until the spring can cope, then follow up with spray grease. One safety note, don't operate the winder electrically with your fingers anywhere near the mechanism - its quite an effective set of power shears!
Door drains and weatherproofing
Door draining and weatherproofing as everything goes back together. The arrangements vary a little from car to car, the later ones have a full plastic skin closing the holes in the inner face of the door. Check the plastic bags around door lock and lock motor where fitted. Check the plastic sheet over the winder motor. All the holes in the inner face of the door should be closed either with tape, the big plastic skin, or with sheet material taped outside the hole at the top edge and tucked inside at the bottom edge so that water runs back into the door. Any water that gets past this is led back into the door, by a 'W' shaped line of mastic along the bottom of the door panel. This little dam guides the drips through two V shaped holes at the point of the mastic W's. On the later cars the mastic also secures the plastic skin. Anything that escapes this, or runs through the main door seal goes back into the door through the round hole in the centre of the lower run of door seal. All water leaves by the two drain holes behind the rubber flap. Check that these lowest drain holes are clear when you finish rust proofing.
That's the lot. If anyone has any other suggestions for making 900 doors (or any other part) last forever I'd like to hear them.
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