Door Stop Repair Options

[olav]

I could use a set too.

[McMark]

I'm interested in the detent and the plastic rollers. the only rollers available aftermarket are aluminum and I'd prefer plastic.

[Engman]

SS - else you have to plate.

M

[davesprinkle]

I'm pursuing quotes on a small production run of the detent cams. However, the cam isn't the only problem with the door detent mechanism. The reason the cams wear out is that the plastic rollers wear far enough to allow the cam to run against the steel roller shaft. Merely replacing the cam won't completely repair the mechanism unless you also replace the damaged rollers.

I'm aware that PP sells replacement rollers machined out of aluminum. However, when I pulled my detent mechanism apart, I found that each mechanism already had 1 Al roller and 1 plastic roller. This makes me wonder if my car's PO has already replaced the rollers with PP's parts. Can someone please verify for me the OE roller material? 2 plastic rollers? 1 Al & 1 plastic?

Thanks for the input.

[andys]

QUOTE (davesprinkle @ Oct 7 2005, 08:06 AM)

I'm pursuing quotes on a small production run of the detent cams. However, the cam isn't the only problem with the door detent mechanism. The reason the cams wear out is that the plastic rollers wear far enough to allow the cam to run against the steel roller shaft. Merely replacing the cam won't completely repair the mechanism unless you also replace the damaged rollers. I'm aware that PP sells replacement rollers machined out of aluminum. However, when I pulled my detent mechanism apart, I found that each mechanism already had 1 Al roller and 1 plastic roller. This makes me wonder if my car's PO has already replaced the rollers with PP's parts. Can someone please verify for me the OE roller material? 2 plastic rollers? 1 Al & 1 plastic? Thanks for the input.

When I removed and repaired mine ('75), they had one aluminum and one plastic roller each. I machined new one's of each. I straight knurled the aluminum roller, and re-created the worn grooves in the cams by hand using a small chisel. Seems the pin's were worn as well, so I machine some of those as well. At least that's how I remember it. I'll have to check my bagged parts. I recall that getting those springs back on was not easy.

Andys

[grasshopper]

I've seen how these things work out...... (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) "I'll see about a small production run"....... 3 weeks later, topic is dropped and forgot about.... just like the engine seals (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif) .................but if it does happen, I'll take a set (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[davesprinkle]

The last post on this topic was a couple of weeks ago, when grasshopper lamented that most reproduction efforts never move from forum topic to physical reality. Well, grasshopper, I'll concede that there is still opportunity for this to fail, but I haven't yet abandoned the effort. Keep the faith.

Meanwhile, a brief update on progress: I have quotes for the detent cam from several vendors with a variety of manufacturing processes. Although the original detent cam was stamped, I suspect that sales volumes won't warrant tooling up a stamping die for the reproduction cam. So, for you concours weinies looking for an identical part, let me state up front that you might consider passing this one up and continue waiting for that dusty NOS part to appear on Ebay some day. But for those of you who are interested in a functional if not identical part, this will perform perfectly.

My experience with the 914 detent mechanism is that the plastic roller first fails and then the cam wears by running against the steel pin. So merely replacing the cam won't resolve the worn roller issue. I'm aware that replacement rollers are available from PP and other vendors, but I have some reservations about replacing the plastic roller with an aluminum version. Quite frankly, the roller needs to be softer than the cam, to avoid flattening the bump by high point loads that exceed the cam material's yield strength. To that end, I've also investigated a replacement plastic roller, machined from Delrin.

My plan is to offer the roller and the cam as a repair kit. My question is this: Do I also need to offer replacement roller pins? What about a replacement aluminum roller for the backside of the cam? I only have limited experience (one relatively low-mileage 914), so I appreciate any feedback from 914 enthusiasts who have more experience with the failure modes of this mechanism.

[davesprinkle]

Sorry for the delay, guys and girls; this has taken longer than I anticipated. Schedule issues aside, I have completed a production run of the 914 door detent cams, cut from 3/16" 6061-T6 aluminum plate. I have also completed a run of Delrin rollers, intended to replace the factory pieces that rapidly get worn through. I am selling both pieces for $34.87 plus actual shipping.

Thanks,

David Sprinkle

[davesprinkle]

Here is an image of the production cam and roller.

[bd1308]

doesn't engman already make these?

b

[thesey914]

Hello, Is that $34.87 for 1 strap & 1 roller?

[dlo914]

QUOTE (mg911guy @ Oct 1 2005, 03:28 PM)

The Pick a Part in Sun Valley (SFV). It still had the engine and tranny. No intake. 1.8L. Side shift linkage was gone. Front and Rear bumpers, doors, Trashed interior. Head light assy's were gone no front trunk lid. But the rear was there. Front Bilsteins were there w rotors and calipers. No Sway Bars. Gas tank was gone. Engine lid was ripped out. No muffler but the exchangers were there. All fenders were there. Windshield was there. I cant remember if the rear glass was there. Hope this helps. Mark... (IMG:http://www.914world.com/bbs2/html/emoticons/sawzall-smiley.gif)

holy crap f'reals i was at the one in el monte/monrovia and there was a white one that was rear-ended all that was good to source was the driver-side front quarter panel, targa bar, rear trailing arms, and two red doors. the 14 was practically stripped. hmm i wonder if the 14 will still be at the one in sun valley. was it located in the back where the bugs are at? or more toward the middle?

Just realized this was posted back in October (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[dwillouby]

Engman makes the arms from SS steel, high quality. You will need to source or make the rollers.

David

[davesprinkle]

QUOTE

Hello, Is that $34.87 for 1 strap & 1 roller?

Yes, $34.87 includes 1 detent cam and 1 plastic roller. $60.00 for 2 of each. (Plus actual shipping.)

[mg911guy]

Daniel yeah that was in Oct. But I went back in Nov. There was a 72 there I got the small window channel rollers. But the eng/trans was gone.

That pAp turns over inventory fast. I have found a 66 911, 924s, 944's and lots and lots of BMWs and Mercedes (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

Maybe we could have a thread that lists the Porsche finds in the pAp yards?

Davesprinkle, Nice Straps. I ended up getting mine from PerfProd. Are you selling the rollers seperate? I could use a set of those.

Mark

[davesprinkle]

QUOTE (mg911guy @ Dec 22 2005, 10:35 AM)

Davesprinkle, Nice Straps. I ended up getting mine from PerfProd. Are you selling the rollers seperate? I could use a set of those.

Hi Mark,

Yes, I will sell the plastic rollers separately. $15.26/each or 2 for $27.74. (Plus actual shipping)

Regards.

David Sprinkle

[davesprinkle]

On advice from McMark, I have added a metal roller to the kit, so that it now includes ALL of the typically worn components in the 914 door stop mechanism: the aluminum door stay, the plastic roller, and the metal roller. (The metal roller was originally aluminum from the factory; you'll note that I've made it from brass. More on that below.)

A brief description of the pieces:
1. The door stay is machined from 6061-T6 aluminum plate, 3/16" thick. This alloy is stronger and harder than that of the OE door stay.
2. The plastic roller is plastic for 1 reason -- to minimize noise. I originally machined a metal replacement and I found that the metal roller was superb at passing the sound of the mechanism into the resonating door skin. The plastic roller, on the other hand, damps the creaking of the springs when the door is opened and closed. Much quieter. Believe me, you want the plastic.
3. The metal roller is machined from brass. The factory originally made this part from aluminum, apparently overlooking the galling problem that occurs when 2 aluminum parts are in loaded contact. Galling is one of the wear mechanisms of the factory part. The brass roller has similar hardness and corrosion resistance to the original aluminum and eliminates the galling problem.

Price for a kit of all 3 pieces is $43.27. Pretty cheap price to save the door-dings in the wife's driver. I have them in stock.

[davesprinkle]

missed the pic last post, oops

[McMark]

Dave, sorry I didn't PM you earlier. (IMG:http://www.914world.com/bbs2/html/emoticons/pinch.gif)

I've got a set of these and installed them last week. Super nice with the rollers. Beats the Performance Products roller replacement kit hands down. This is obviously a well thought out replacement, far far far above just a "should be fine" replacement (like the PP kit is). It's great to have the whole package, ready to roll. (IMG:http://www.914world.com/bbs2/html/emoticons/lol2.gif)

Nice work Dave. Did you start a thread in the Parts forum?

[davesprinkle]

Yeah, Mark, thanks for pointing out that the Parts forum is the proper place for this thread. Shoulda done that from the outset. Oops. Only 40 posts to my credit and already I'm about to see the dark side of the BAMFH.