My assistant recently swapped out the starter on our 1991 Volvo 240, with the B230 engine. The starter attaches to the engine with two 4"-long 18mm bolts. The heads on the bolts face towards the rear of the car. From underneath the car, the bolts are easy to see, and removing the wiring and the lower bolt was easy. The top bolt was very, very difficult to remove, and my traditional bolt-loosening techniques didn't solve the problem.
Last Updated: 03/29/2016
Parts Group: Starter
A box end wrench fitted onto the bolt head, but there wasn't enough room to swing the wrench. For a socket with a ratchet directly attached, there wasn't enough space. The only thing that worked for us was a socket with many extensions put together, and with a universal joint interspersed, to effectively make a very long extension -- but then due to the limited space, the angle of the extensions was so extreme that it was impossible to put enough torque on the bolt. The socket kept slipping off the bolt, due to the angle.
I searched many websites, and the best suggestion I found was to improve the odds by gently pushing the transmission away from the starter bolt area, i.e., towards the passenger side. The engine mounts and transmission mounts have a fair amount of "give" and so this worked well. My assistant used a long piece of 2"x4" wood, held in place with a strap. This provides enough space for the angle of the socket to be less extreme, so she could apply enough torque, and the bolt came loose. Success ... but not without some collateral damage: The Wiring atop the Automatic Transmission. And she did MUCH better than most: : Starter Removal: Tragicomical Stories of Desperation. One useful discovery was this: Can a six-point socket apply more torque?.
When it comes time to re-install, this might be useful: Starter Bolt Fastening Torque on Volvo 240 engines and so might this: Starter Wiring