The driver's side wiper arm came off its spindle while in use in the rain. Thankfully I wasn't going very fast and the arm and blade assembly stayed laying on the hood until I could stop. But it's unclear how to reattach it so this doesn't happen again. Please advise! And is there anything I should do to prevent this from also happening on the passenger side? Thanks in advance!

Dean;

See also: https://www.sw-em.com/Wiper_Arm_and_Blade_Notes.htm

Cheers

Very helpful!!
What I had thought was the drive post (that's supposed to have a bushing on it, which then fits into the arm) is instead sticking up naked. Meanwhile, the bushing is stuck inside the arm itself, obviously having come separated from the post on some previous owner occasion. And I worry that the passenger side wiper may be the same.
Would you recommend that I try to pry the bushings out of the arms and get them reattached to their drive posts -- or buy the Thunderbird wiper pivot repair kit bushings, and order new arms from VP Autoparts?

If the Thunderbird has a set screw to lock onto the shaft, I would go with those. I found some that have two set screws in the. They work perfectly .

Yes. Thanks! I've obtained the T-bird bushings (which do come with set screws) and they work fine to marry the wiper arms to their posts. But now the under-dash mechanism has stopped propelling the passenger side wiper. GRRR. Two steps forward, one step back...

What is the shaft diameter that these fit to? If these are 1/4" those living in the UK might be able to use these. I haven't tried but they look as if they would work, even if you have to file a flat on the shaft for the set screw.
https://www.carbuilder.com/uk/135mm-splined-wiper-arm-adapter?gclid=CjwKCAjw3MSHBhB3EiwAxcaEu1o_7qtNSnIl4iE1_exdw-3OakkytmnB-_1s2eZgBlntBEKrb_rq5xoCqFUQAvD_BwE

The set screw has a pointy end that tightens (by tiny allen wrench) into any of the grooves between the vertical splines on the post. Seems to hold just fine with no need for flattening a surface.

https://www.speedwaymotors.com/Specialty-Power-Windows-Wiper-Knurl-Stub-0-25-Inch-I-D-,228299.html?sku=91123318&utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE

I hope it's an easy fix.

Did the wiper arm come off the fine splined hub or did the fine splined hub come off the wiper post?

If the fine splined hub came off, it will be inside the end of the wiper arm.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

It came off the splined hub, and it looks like the small restraining clip on the splined hub had slipped upward, giving less surface for the arm's hole to grip onto. Also looks like the hole in the arm has lost some of its reciprocal spliny interior surface, probably just from years of wear. Time to buy new arms? And I guess it's then a two-man process to install them -- one to push the arm's hole onto the hub and the other to push upward on the underside of the hub's mechanism to assure the clip doesn't just slip again?