> When I sit for any length of time driving the 89 240 DL, my left

> gluteus maximus suffers discomfort followed by numbness that is only

> relieved by changing my sitting position. My wife in the passenger

> seat also complains of discomfort from the seat to the point that she

> is ready to sell (I hate that word) car. My theory is that the seat

> heater is causing the aforementioned numbness and discomfort. I want

> to remove the heaters and fill in or replace the seat bottoms to try

> to solve the dilemma. What do you think? Thanks

The seat heaters are in a plastic frame. When the padding on top gets compacted the heater frame will start to make an impression on you, unless you're a very cheeky individual. You need to peel back the upholstery starting from the rear of the cushion to expose the heater. This will allow you to insert a thin foam pad on top of the heater. Not too thick or your buns will never feel the heat. You don't want foam that can melt (those wires can get hot) or easily catch fire (it has happened). The only trick you really need to know is about the metal strip in the hem at the back that's a bit of a struggle to get out and back in. Note how the ends are slotted into the frame before you start. You have to bend it out in the middle and then pop the ends out of the slots so you can slide the bar out of the hem. Also, if your seat heater isn't working and you want to fix it, now's a good time.

Unfortunately in your case this may not be the only problem.

The foam used in the front seat cushions in 240's in the late 80's seems to be inferior and is known to compact, most notably on the outer edge of the driver's seat. In the early stages of decay, a transplant between the driver and passenger side will normally do for awhile (either people or seat cushion). As you've gone beyond that, it's off to the wrecking yard looking for seats with good foam. The passenger side will usually be best. Any model year having the same seat style will do. Don't worry about matching the upholstery, it's not that hard to re-skin them. The only trick you might want to know is using nylon ties to replace the hog rings you'll have to cut. Other than that it's either a new cushion from Volvo or a visit to a good custom auto upholstery shop. The latter may be easier on your wallet. Speaking of which, keeping your wallet in a hip pocket does not make for comfortable seating.

As others mentioned, make sure that the wire support grid under the cushion is still properly together and no springs are loose or broken. They sometimes start to fall apart, especially at the front. If you want to try additional padding on top of the wire grid then you'll want to put some heavy fabric in between to keep the wires from chafing the pad.

Make sure that the seat frame is straight and properly adjusted. Loose bolts can easily allow the seat to twist. The driver's side seat tilt and height is adjusted with levers on the underside fore and aft. The passenger side is adjustable at the back with bolts and a series of holes. The front is adjustable by the threaded support rod.