98 V70/T5: RR Door Lock Actuator Internal Spring

[v-45magna]

I clamped and waited, probably only about an hour or so though. I wanted to finish sooner, too. But I found something else to do as I think I'd just as soon have a prostate exam as have to fix something flying apart after installed. I used 'Goop - Automotive' silicone. Seemed very solid and waterproof when done.

You might also put a dab of silicone in the door pin lever that mounts the bar that goes to the door pin (sticks out of the top of the panel). If you fill it with silicone, it should still work after it breaks. See this link:
https://www.matthewsvolvosite.com/forums ... 68#p375168

[sleddriver]

Installed the LR lock earlier and it's working fine. The 100% white silicone cured thoroughly and strong, so it won't be coming apart again.

Now, back to the RR one I'm having SPRING problems with

This is the lower white gear. The spring installs underneath it. This gear drives the whole lock/unlock mechanism:

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With the gear & spring removed, you see this. That "ramp" looks like a place to catch one end of the spring into that small notch. Opposite this is smooth and straight, all the way to the "floor". However a spring "hook" could still catch here.

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Note the two spring "hooks" are roughly 180° apart, the top one tilts down while the bottom one, tilts up. So if you rotate the spring 180° CW, the lower hook will hit the bottom of the plastic "tower".

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Like this:

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The gear, shaft and "flat" are all one piece and run through the plastic base, and fit into a small, white arm on the other side. The small teeth engage an inner "star" in the lever, not another gear. One side of the white projection has a small recess inside the circumference, so I figured the end of the spring hook would fit there. (Can't see the flat cut into the shaft from this perspective).

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You can see it here at 9 o'clock. I'm not sure what purpose the hole in the solid gear disc serves. Any ideas?

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On a properly working assembly, the spring torque is so high I can barely move the white gear with a fingernail AND the tension is felt both directions, so the mechanism isn't "locked" or unable to rotate in the opposite direction. I've been looking at this thing for hours, trying to figure it out. How it was installed, wound. I'm stumped.....

The spring is necessary to return the mechanism to center. The motor must be bi-directional, so the polarity is inverted by the controller to spin the motor in the opposite direction, thus locking/unlocking the mechanism.

Even bringing both ends of the spring together results in distorsion of the spring body. It's why I was having so much trouble trying to "cock" the spring, and set the gear in place so it would be held under tension. But that didn't fix it. With just two parts, it would appear to be simple. But I'm obviously missing something.....

I'm all ears if someone wants to explain how this spring is supposed to fit in place.

[sleddriver]

I just remembered I kept the drivers lock mechanism when it failed last year. I couldn't open the door from the inside at all. Had to roll down the window and reach out. It's a bit different. I noticed that the mechanism didn't have any spring tension on it. I heated up the motor cover seams with a micro torch, then carefully pried it off and discovered that the spring inside had failed: One end was broken off! Well, that gives me a spare motor. Noticed there is no "evil red lever" in this drivers front latch like in both the LR and RR latches.

[sleddriver]

I've been tinkering some more with this. I'm wondering if the mechanism needs to be put in a certain position first? Tried a few variations, but still no tension. Reinserted the motor, then plastic lid, clamped it shut and applied +12, then -12VDC. It does lock, then unlock. However, the mechanism doesn't return to CENTER as others that work. Looks like I'll researching nearby PNP yards for a replacement as driving around with no latch on a rear door is a bit odd.......

[sleddriver]

You might also put a dab of silicone in the door pin lever that mounts the bar that goes to the door pin (sticks out of the top of the panel). If you fill it with silicone, it should still work after it breaks. See this link:
https://www.matthewsvolvosite.com/forums ... 68#p375168

Nice touch. I added a brief squeeze of hot glue in there. Thanks.

[sleddriver]

Finally got around to researching some local PNP's and visited one this afternoon for a walk. Found about 6 S/V 70's, that came in within the past few months. I'm doubting that though as more than a few were extremely picked over & the interiors were trashed.

So I'll clean the latch, install an updated motor and lube the sliding pieces. Looking forward to crossing this task off the list....

[sleddriver]

I gave up trying to reinstall the spring properly...don't have a clue and it's a dead end. Time to move on.

Made another trip to the PNP, pulled a RF and RR latch mechanisms out of different cars. One latch had a date code of 2003. From another car, I also pulled two fog lamps, a dash switch & the big relay, next to the red fuel pump relay. However, couldn't find at all the relays/jumpers under the dash. One was a 99 I think, the other an XC70 of similar yearage.

I watched RSPI's video's of this but what I saw looked different from his video. He showed rather clear access, what I saw was blocked by a large wiring harness connector, about 1x5 or x6. Didn't think to bring a mirror & flashlight. Frustrating to have only gotten part of the fog light parts.

At home, I pulled both covers off the latches, replaced the PTC's with copper, cleaned & lubed all the sliding contacts, then went to test on the bench. It would move the motor a little but that was it. A far cry from the repaired LR latch previously tested. Next, I used the sled battery for power and both latches moved much further, but something is odd as they won't complete a cycle in order to full raise the vertical lock pull.

What are the odds of pulling two latches out of two different cars and not having them work properly?

Is there something different about 99 (CANBUS?) or later latches? There was a 2003 latch, the date code yr was worn off on the other one.

Something's gone wobbly here. As if I wasn't already frustrated enough dealing with all the upkeep the past 6 months now. The RR door has been tied shut with rope most of the week as well.

Holy Cow is it HOT in a dusty junkyard during Summer in Tx! According to my weather station, the solar heat index at 4pm this afternoon was 136°F. It felt like it!

[sleddriver]

UPDATE:
I took both repaired latches outside, hooked them up one-at-a-time to the RR door electrical connectors, and cycled the door locks. SUCCESS!! Not sure why doing this with the battery showed different results? Odd that....Perhaps the locking controller sends a different signal than just + POWER/-POWER?

Geeze this old car is giving my gray hair...grey hair. Man Alive! Obviously, it's difficult for me to focus on something else when I'm confronted with a problem I either don't understand or haven't figured out yet. It's like being nailed to it or having my mind hijacked by it. I indeed admire those who can just LEAVE IT and go on to something else.

BTW, any of ya'll run into some seriously mentally unstable people at junk yards? I won't be returning to the one I pulled these parts from. Barking, mad Moon-bat comes to mind.