928wolf

Update:

My driver's side door has been exhibiting this condition for several months, still able to open the door but with a lot of effort. A couple of times when it was pretty hot outside I couldn't open it at all. The fact that many people reported the problem first showed itself when it was hot outside, and that the inside door lever still works, told me this was an adjustment problem of a very sensitive mechanism. Being inherently lazy and not taking enjoyment in tackling difficult repair jobs, I went looking for an easier way to deal with this issue.

So I looked into how the handle operates, from the pictures in this thread, parts catalog, etc. The handle operation, whether the cable operated inside door handle or the linkage mechanism for the outside handle, both move a part that kicks the spring loaded door latch open (see pictures open and locked). The difference between it working and not working is very small, as little as 1 mm. The cable operated inside door lever doesn't seem to have any problem because it actuates a different lever that moves this link, the cable allows a longer linear pull which gives more leeway to absorb small tolerance differences. The outside handle mechanism obviously cannot take small variations, probably due to wear. A mechanism that goes from working to not working due to temperature is pretty darn sensitive, metal parts are only going to expand and contract by tiny amounts in normal ambient temperature ranges, plastic parts a little more but still not a lot.

So the mechanism goes out of adjustment, causing the amount of force needed to open it to go up, this puts more load on the handle mechanism, which looks like it is a (relatively brittle) casting. The higher loads start fatiguing the metal, then one day it breaks.

I noticed that there is an adjustable link between the handle lever and the door latch lever (see pictures). The Engineers put that in there for a reason. Either the mechanism is sensitive enough that it can't be accurately set on an assembly line without an adjustment or the mechanism wears over it's life and needs the ability to accommodate over time, or both. I suspect it is both, so I took advantage of the adjustment our friends in Weissach gave us, regardless of why they did it.

The worst part of the job was figuring out how to get the door panels off without damaging them, and that aggravating security plate. Once I got hands in there (barely) I can see why replacing the door handle is such a pain.

I got in there, popped the adjustable link off the pin, turned it 4 turns and it worked just fine. While the link was off I actuated the lever from the inside and tried get it to move the kick-out piece the same amount as the inside door handle moves it. This looks like only about 3-5 mm (if these are 1mm threads) but it was enough to make it work like new, or at least like my passenger side door. Make sure you tighten down the nut on the turnbuckle so everything stays tight. Don't adjust the amount I did, adjust it the amount that makes your mechanism work properly.

I may have only held off having to replace the door handle, but hopefully for several years. Fatigue is an additive process, you can't undo the damage but you can keep from doing any more.

My advice: the minute your door handle gets difficult to operate make this adjustment (I let mine go for months), it's much easier than replacing it.

Note: To get that pesky security plate out, follow the steps in this thread plus one: Once you have the plate loose, CAREFULLY lower the window all the way down and it practically falls out. It took 15 minutes of aggravation to get there.

928wolf

This morning I did some more investigation. It appears that one of the tabs that mounts to the outside handle is broken. The reason the mechanism still works is that it is connected through a rod to the other side. Now all of the load is being taken the forward tab, transmitted to the lever by through the rod. The extra adjustment allows the mechanism to work with the extra flexure due to all the load being taken by the forward tab. It appears that in normal operation most of the load is taken by the rear tab directly into the lever. But there is a stress riser in the transition from the tab to the lever where it necks down, and a parting line in the casting right down the center of the load path, a prime spot for a fatigue crack to develop. Hopefully the other tab has a lot more life in it.

How long will it live? Who knows, depends on how much margin the Engineers designed into the handle. We'll find out.

9two8

I admire your tenacity, however you won,t stop the inevitable, they all display the exact symptoms of inevitable failure ,... sooner or later, I say just get it over with...., bit like a visit to the dentist


Ken
80 928 S
5 Speed

UK

Alan

No need to wait here - it is quite clearly already broken in exactly the classical way - just get a new hinge and fix it while it is all fresh in your mind.

I don't think it went out of adjustment - it just broke, adjusting just made it barely work for a while...

Alan

jflorance55

I've got an 88 with a similar problem. The Driver's door will not open from the outside unless I press the lower rear part of the side glass firmly while lifting and pulling the door handle. Then, with some luck, the door opens. I suspect the same fix will work for me. What do you think?

Alan

Yes.

Alan

NoVector

Thanks Alan for this excellent guide. To help others in the future, just adding a couple more pictures.

demetan

Very usefull thread Alan & all members that replyed. I have the same problem on my passenger side's door ROW (Japan) 89 S4. The last owner told me it was an easy fix & just needed a weld tack to repair (???...) for the moment, I simply open the door from the inside & it's becomming a bummer.

I figure it's the same procedure 'mirror' like (left is right & vice-versa)?

Where do you buy panel fasteners in bulk & is there any aftermarket parts or genuine Porsche for the door hinge?

Best thread or link for door inner cover removal? (to save time...)

Thank's

NoVector

I don't know about right vs. left door. The white plastic door clips are part #433-867-299-A and run about a buck each. The hinge itself is Porsche and is surprisingly cheap (for Porsche anyway.) I ordered from Roger (928s R Us) and I think it was around $55. Alan has the hinge part number in his first post. I'm VERY slow and this took me about 3 hours. Good luck!

Alan

Doors are basically a mirror image - same instructions apply, get the correct hinge.

Poor design and/or materials - these should not break consistently like this - seems it is far too common a failure...

Chalk up another to the Porsche "B-Team" - they get all over...

Alan

9two8

Maybe down to poor quality pot metal casting.., from a "cheaper than the rest" outside supplier ? hence why it,s not the usual high price Porsche item.

hacker-pschorr

It's definitely a 928 spring for me. Installed a clutch master a few weeks ago in the 78, and the drivers side door handle broke today in the 87.
Everyone outside the restaurant thought I was being a gentlemen getting the door for Lorelei....yea well....she needed to get in first

I think I'm just going to cut a hole in the door to make this job a lot easier........

To add insult to injury, I finalized an order from 928 International yesterday, already shipped.

Anyway, thanks for the write-up Alan, it doesn't look too horrible with your photos as a guide.

RFJ

I have done this twice but still want to say thanks to Alan and everyone else as it will be much easier now!!

dr bob

Just started this project. The driver's door opened OK to move the car from its hibernation spot, but a couple actions later it no longer worked. It would have been more, um, inconvenient had the hinge failed a few actions sooner, as there was no easy way to get into the car where it was stored tight against the wall.

Also can't say enough good things about the instructions and pictures shared by Alan and the group. I'll add a couple pieces of info that may help others.

-- The bolt that's hidden by the security shield is actually the rear door brace bolt. The door brace is a US-mandated tube that runs fore and aft in the door an inch or so inside the outer door skin. The "beam" doesn't look like it will withstand much of an impact, but it's tight between the latch area and the hinge area so would have to stretch to allow intrusion through the door. So follow that beam towards the rear of the door and you'll easily find the bolt.

-- After the bolt is "broken loose" with a box-end wrench, a stubby 13mm GearWrench is perfect for getting the bolt out further. I completely removed it as I fiddled with getting the shield out. Finally lowered the window to allow the shield to rotate out, and left the shield in the bottom of the door. Bolt went back in part way in anticipation of refitting the shield.

-- The little Allen-head capscrews that connect the hinge to the handle need a 4mm Allen key. A long 4mm ball-end hex key will make removal a LOT easier, vs trying to fumble with a standard hex key. Especially helpful for the rear fastener.


New hinge is on the way from Tom at 928 International, along with a new front AC expansion valve. That expansion valve is a separate story for later.

Mrmerlin

I mentioned it before but incase anyone missed it,
make sure to lubricate the lock mechanism before buttoning up the door,
this part becomes sticky from water or lube dry out and is a casual participant in the hinge failure