Does anyone know what symptoms a bad or fading steering box can give off? Specifically - will it pulse 2-3 times per second at low revs when shifted into Reverse. I'm feeling (in the wheel mostly) a pulse right after - almost immediatly upon shifting into Reverse - as the revs drop on engagement.

This is also happening in Drive, especially when turning right at low revs (downhill turns foot on the brake, uphill into a driveway...) Not really noticable turning left. But sometimes after a cold morning start up when steering straight and braking for a stop sign, the revs drop and the pulsing starts. But they are heaviest when shifting into reverse, and go away when I accelerate in reverse or forward.

So far I've suspected/inspected the ABS, power steering, and brake vac. I've swapped the ABS brake sensors, put new power steering filter and fluid (turkey bastered out the reservoir only.), and replaced the brake booster vac line.

What other sources should be checked? tranny, mounts, ps pump, ...?

Steering box probably original with 290k miles. Are they the same steering box as in a TE?

Anyone know of a diy on this project?

I was heading throuth LA and stopped by Sun Valley Mercedes Dismantlers.com. Their diagnosis is motor mounts, as the engine really kicks over to the side. Mounts are probably due.