When attempting to remove a 30+ year old overdrive solenoid on my '90 740 GL with the AW70 transmission one of the 2 bolts securing it broke off. I didn't even attempt to remove the other bolt. There is now just 1 bolt holding the solenoid in place. Will the car be okay to drive like this? Is there a way to remove the broken bolt without removing the transmission from the car? Thanks.

If the bolt broke at the head, it's possible the shaft of the bolt has enough corrosion to hold the solenoid in place for a while.

There's not a lot of room in that area, so it wouldn't surprise me if you had to pull the transmission.

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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Thanks for your reply. Yes, that's what I was thinking - that there is enough corrosion in that area and on the shaft of the broken bolt to hold things in place. I didn't mention it in the original post but I also reattached the head of the broken bolt to the shaft with some J-B Weld - making sure to put on enough that it spilled under the washer and head of the bolt onto the solenoid base. Between that and the corrosion I am hoping that it will stay put. But one day that overdrive solenoid may have to be replaced. I'm afraid that's when the real fun will start! Removing the transmission may then be the only option. :(

In my car there was not so much corrosion but oil mixed with road grime, so taking them out was a matter of cleaning the area with judicious use of a can of brake cleaner and a toothbrush.

If yours broken loose, can you feel/look if there is enough of the bolt left above the transmission? Also, start coating the area with some rust penetrant.

While it would be ideal to take the tranny out, you may get enough room by removing driveshaft and distributor, disconnecting the shifter and then unbolting the transmission crossmember while holding it with a jack. In other words, similar setup as doing the https://www.brickboard.com/FAQ/700-900/TransmissionAuto.htm#Trans_Output_Shaft_Bushing

Fun fact: if you suspect a bolt is wrapped in corrosion, spraying rust penetrant and then tapping the head (no Hulk Smash here) may be enough to loose it.