Replacement for rocker body plugs

Anyone with a Mk3 that's been underneath their car working on something knows by now that the body plugs used in the rockers (and elsewhere) are pretty cheap. The ones in my 97 TDI (and I think in the B3V too) are just molded plastic and they don't stand up well over time, and finding replacements from other VWs, well, that was basically a dead end in most cases because they all used the same ones.

So for quite a while now I've been looking around the JY for body plugs from other makers that are rubber and provide a better fit.

VW claims the hole is 30mm (there are other sizes too) and so far the following plugs from other makers seem to be a good alternative. They are rubber and decent

GM 94535738 - This was found in quantity on Suzuki Esteem (maybe 10 per car) but was used on other cars too. These are technically sized at around 31-2 based on measurements but listed online as 35. They fit is tight but worth the effort as they won't fall out.

Toyota 90950-01958 - This plug has a 30mm marking on it but online it is listed as 31.5 size. It's a good alternative but after scouring a number of Toyota models I could only find a few, and the models that use it only have 1-2 per car. The fit is also not as robust as the other but it's easier to install. While it fits snugly I wouldn't be surprised to find it missing after a while. It's better for vertical installs and I might use a tad bit of rtv on it.

I resorted to this after trying to find a bulk vendor for 30mm rubber body plugs online and all I could seem to find was assortments, none of which included any in the 30mm size (or close enough to work).

If anyone has found a good source for replacements please post up, I'm interested in getting these holes plugged on all my cars so that garbage doesn't accumulate up in there. I'll also be looking at alternatives for other sized body plugs, there are some 40mm ones too but I haven't looked for anything in that size yet.

Steve

you can make your own plugs.
there are only like 5 or 6 sizes, maybe less. ive used this trick a few times on other things but same application can apply.

get some silicone mold 2 part putty, follow directions and make a mold on the bottom side making sure to press plenty of it in and have someone or make a jig that presses down on the carpet or a backing plate. push a flat stock of whatever on the other side, sets up in like 5 minutes after mixing. take this and make a mold out of it and get some poly red caulking and make your own plugs out of polyurethane type material. might not be stock looking but will definitely work best vs anything you get. i just recently learned this trick on a video where they guy was making plugs for hydraulic tanks with ODD ball shaped holes.

i've searches day and night for a long time to find plugs for my mk3 but im not willing to pay a ridiculous price for used plugs and nearly none exist that wont fail quickly.

I had big plans to start fabbing my own plugs out of silicone, after reading about a DIY mix of silicone, paint thinner and cornstarch. If successful, I figured the technique could be applied to radiator hoses and other goodies.

It didn't go well, so I gave up. Maybe those arts & crafts youtubers were more diligent at it, but I suspect those materials just aren't right. There are pro kits and materials, but the price point never sat right with me. I figure if you can buy a 10oz tube of 100% silicone caulk for $3.00, a moldable, more fluid version should be available for about that, or maybe 50% higher.

It was long enough ago, that Mongler's 2-part putty deserves a look. People may need to get serious about finding (or being) a backup source for NLA parts, or even current parts, if the supply chain shatters like it nearly just did.

Right on time, I just noticed all the missing plugs last time I was underneath. We've got a good selection of knock out plugs for electrical panels at work. I'm planning to see if any of those match up.

the silicone in a caulking tube is nothing like the silicone in mold making. Silicone is a group of whatever polymers the product needs, no 2 are identical in products.
think of silicone as a brand name, (kinda)
i make a mould of my head in a pottery class and i used this stuff for my ears and eyes and nose, works REALLY WELL. kinda pricey, about $30 for the amount you would need to do this job.
IMO, some stainless sheet metal cut outs, some pop rivets and a lot of undercoating and your done, FOREVER.
the plugs are there so that when the car was made it was dipped in a tank of paint to trap all the rust it had (quote from birdman's restoration) and the holes are to drain it all. that's it, no other reason for them to be there. patch them up good. just don't trap any more rust lol.

Correction to my original post, it was a Suzuki Forenza, not Esteem.

I found two more today and harvested all the plugs I could, each one has 19 of these ~31mm body plugs.

I'll be moving on to the larger ones next, if they're 45mm then I already have a common candidate from Toyota. I will post back with any other substitutes when I find them.

Steve

EDIT: I also found some others that might substitute for the 30mm plugs. As soon as I identify those I'll post back about them.

My experience found there was always rust/rot around these plugs. I cut, welded and seam sealed. Problem solved.

Another easy fix would be to use tape and seam seal over it. VW did that a lot on the earlier cars, such as Rabbits. I’d probably apply the tape from the inside... pretty cheesy, but it works.

-Todd

ToddA1 said:

My experience found there was always rust/rot around these plugs. I cut, welded and seam sealed. Problem solved.
Another easy fix would be to use tape and seam seal over it. VW did that a lot on the earlier cars, such as Rabbits. I’d probably apply the tape from the inside... pretty cheesy, but it works.
-Todd

Click to expand...

That's true, I've seen the tape before that has some sealant slathered over it. In the rocker though there's no way to do anything from the inside, so you'd have to tape the exterior and then seal over that and hope for the best.

Hyundai also used a 30mm plug, part number 17313-30000. It can be found under the back seat, but I've only found two on each car. I believe a circa 2008 Sonata can provide them.

Steve

If you scraped off the shutz, or whatever’s there, and prepped properly, I’m sure Gorilla tape would stick. That stuff is evil.

How’s this... https://www.amazon.com/Magic-shell-...words=30mm+plug+rubber&qid=1585282962&sr=8-22

-Todd

ToddA1 said:

If you scraped off the shutz, or whatever’s there, and prepped properly, I’m sure Gorilla tape would stick. That stuff is evil.

How’s this... https://www.amazon.com/Magic-shell-...words=30mm+plug+rubber&qid=1585282962&sr=8-22

-Todd

Click to expand...

Those would probably work, I had looked on Amazon but never saw anything in the size I needed. It appears those are to be pierced for wiring so they might be very thin in the center but otherwise they would work. The GM ones I have are thick, they cannot be used for wiring.

I like Gorilla tape, it's very good for booting a bike tire when there's a cut i the sidewall. It will stick to that like nothing else I've found, even better than real Park brand bike tire boots.

Steve

Quality HVAC tape. Once it's on. That is. It ain't coming off.

Yeah, they may be blanking plugs. Fill them with ultra gray, lol.

-Todd.

A quick search for "1-3/4 body plug" turns up many options as does 1-7/8". I find searching by inches gets far more results in the U.S. You may be able to refine your search with closer fractions. When I removed the grease kit from one of the wagons I ordered body plugs this way to seal the holes where the grease lines went through the cargo floor pan.