My mechanic suggests (doesn't necessarily recommend) replacing the torque converter on my 1999 S70 AWD (116K miles).

I brought it in to the shop due to "surging" and they replaced the transmission fluid. This didn't fix the problem.

Now it's replace transmission or maybe just the torque converter .

I've read that the TC solenoid can fail. Should the entire TC be replaced or just the solenoid?

The difference in cost may be neglible as he's offer to swap a TC from a parts car he has. Consequently, labor is the main cost. The shop earlier referred to a 'solenoid deep in the transmission.'

I wonder what's the best use of my cash: 1) donate the car as is, 2) replace the solenoid in the TC, 3) replace the TC, 4) replace the entire transmission OR 5) something else.

Thanks for all advice.

 

In all of the cars that we've sold and repaired, I've never had to replace a torque converter on a Volvo of that vintage. Typically, the solenoids in the transmission can fail and changing the fluid 10,000 times will do nothing to solve the problem. It becomes a waste of time.

You're looking at about $3200 for a Volvo rebuilt unit, installed by a competent shop. I'd look further to diagnose before pulling out the transmission.

You need to KNOW the problem before repairs are begun.

 

The torque converter and the TC lockup solenoid are 2 different parts. Either way, the trans probably has to be removed from the car to do the work, however. It MIGHT be possible to replace the solenoids with it in place, but it's hard to do. My recommendation to you is to get a second opinion. Go to a Volvo specialist of a European car specialist, and have them look at it to see what they think is going on. I've NEVER seen the TC itself go bad on one of these- I have seen many solenoid failures, however, and I've also seen electrical/ wiring issues, which needs to be ruled out before doing major repairs. Fluid flushes can sometimes help on an abused trans in one of these cars that is having issues with "sticky" or hard shifts... But any other transmission problems... they might have been prevented by changing the fluid when it was due, but it's too late once problems start.