OIL PLUG THREAD SIZE?

tedder · **Joined:** Thu Sep 15, 2011 7:19 pm **Posts:** 137

My oil pan is stripped and want to insert it but don't know what size the threads are anyone know? I could drain the oil but just put it in and don't want to spend $50 bucks again just to find out the thread size.

Thanks, John

wolcott · **Joined:** Thu Nov 10, 2005 4:16 pm **Posts:** 108

It is a straight pipe thread. If you search through the posts on this forum, you should be able to find what size it is.

Gokeeper · **Posted:** Tue Mar 13, 2012 11:52 am

Drain Plug size is 5/8" X 18 TPI which is standard SAE fine thread

Found Here
viewtopic.php?f=98&t=31949

If you need to drill and retap look here
viewtopic.php?f=98&t=56726

and Now you really need to get a Fumoto Drain Valve solve all your problems.

papaindigo · **Posted:** Tue Mar 13, 2012 1:44 pm

see also viewtopic.php?f=5&t=63191&p=698855&hilit=fumoto#p698855

tedder · **Joined:** Thu Sep 15, 2011 7:19 pm **Posts:** 137

Thanks for the input. I have a experiment I want to do what size Fumoto valve fits a stock pan? Fumoto says PF 3/8 which is a F-102 is this the same vlave as you got? The reason is I've seen 4 ro 5 different size thread for the drain plug so I' thinking there is some variation somewhere????

geordi · **Posted:** Tue Mar 13, 2012 2:14 pm

Papaindigo nailed it with that link, that is exactly what I did and it has been working PERFECTLY for 3 oil changes now.

No leaks, no loosening of the plug, the only thing I would add is that when snugging down on the o-ring, it looks like I am flattening the o-ring, but I don't go far enough to really crush it or have it spread out past the shoulder of the standard plug I'm using. The o-ring was NOT a snug fit around the threads of the bolt, it was just a touch wider, to drop on easily and not wander too much side-to-side. This bolt has threads all the way to the shoulder, there is NOT any gap at the shoulder or narrower spot like on a normal drain plug.

(which is why our stock threads get wrecked - oil monkey puts stock plug in without proper washer, wider base on plug jams and strips hole. Another brilliant Chrysler design choice.)

What you are seeing as far as variations in Fumitomo selection is largely based on the damage that people have done to their pan, replacing the drain plug with an incorrect match or an oversized plug which is designed to cut new larger threads into damaged holes... But can only do so to a point. Get the permanent thread repair that I used (NOT a helicoil) and I can safely say you will not need to worry about this again. If you want to then get a Fumitomo... You will know *exactly* what the threads are, from the kit. If you use the same kit I did, you will end up with M14-1.25 threads.

tedder · **Joined:** Thu Sep 15, 2011 7:19 pm **Posts:** 137

I found a TimeSert insert kit M16x1.5 and a Fumoto valve F-108 which is a M16x1.5. How's that sound?

turbobike · **Posted:** Tue Mar 13, 2012 4:38 pm

you need the following:

Fumoto F-104
41/64 drill bit
18x1.5mm tap

drill the hole
retap the hole
install the Fumoto
never worry about it again

geordi · **Posted:** Tue Mar 13, 2012 4:59 pm

Is the insert a solid collar?

I don't know about a 16mm collar fitting in the hole, you do want the thread tap to actually cut something on the oil pan so that the collar has something to bite into. The measurement might be correct based on the fact that my single-oversized drain plug was "just a bit" larger than the stock size (which was long gone) and the M14 kit I bought had (IIRC) an M18 thread tap for the hole, which was again, "just a bit" larger than the hole it was drilling, so perfectly sized to cut the threads for the collar. The "single oversized" plug is effectively its own thread tap, which is why that (if this is the original size) 5/8 hole wasn't 5/8 anymore. I went with the metric sizes simply b/c I was making new threads anyway, and that is what the parts store had that I could attempt to match up.

If you are still dealing with the stock threads that are now ripped, the M16 thread tap might work for you. You want it to be snug cutting the threads, but not bind up to the point where you are really having to gorilla it. That would mean that the hole is still too small for that tap. Also back it out a few times while cutting to make sure you get a smooth set of threads for the collar.

geordi · **Posted:** Tue Mar 13, 2012 5:05 pm

turbobike wrote:

you need the following:

Fumoto F-104
41/64 drill bit
18x1.5mm tap

drill the hole
retap the hole
install the Fumoto
never worry about it again

Could you have picked a harder-to-locate drill size?

What he (and anyone else) doesn't want to do is end up using the SAME soft aluminum oil pan surface for a continual application of torque on installing an oil plug. Yes, I know that the Fumitomo shouldn't need to be removed ever... That doesn't mean it won't be or someday get loose. The fact is that the aluminum threads aren't strong b/c this was a cast aluminum pan - Lighter and cheaper than forged, and WEAK. Using a solid collar for re-threading, the actual size of the hole is irrelevant if there is a plug or Fumitomo to match it. I wouldn't do this again without lining the hole with stronger stuff.

Joe Romas · **Posted:** Tue Mar 13, 2012 5:29 pm

Gokeeper wrote:

Drain Plug size is 5/8" X 18 TPI which is standard SAE fine thread

Found Here
viewtopic.php?f=98&t=31949

NO IT'S NOT!!!!
Read all of the thread :BANANA:

Every time this question is asked the same old misinformation pops up.

Anybody who thinks it's 5/8" x 18 tpi get a 5/8" x 18 tpi threading die or nut and try screwing the drain plug in. IT WON"T GO IN.. Some say it's a 3/8" NPT, try that and you'll see the drain plug swims in a female 3/8" NPT fitting.
This engine is made in Italy, what makes anyone think there are SAE fasteners in it :dead:

And it's not 18mm x 1.50 either.

See this thread for the real deal, it's a PF 3/8
viewtopic.php?f=5&t=40736&p=434753#p434753

You'll all learn it's a some kind of special pipe thread and is 19 tpi... :furious:

Gokeeper · **Posted:** Tue Mar 13, 2012 6:04 pm

Sorry for the miss information. Joe is correct the size is odd. I was curriouses so I grabbed my old plug and messured it. Came out as 16.4mm with 1.33mm pitch. That is neither BSW or SAE, basically an oddity. Best to get the Fumoto F-102 (PF-3/8)

In your case and mine use a 41/64 drill or 16.5mm and a 18mm x 1.5 (f-104) fumoto

41/64 isn't too hard to locate, just be prepared to pay,locally mine was $27.00

geordi · **Posted:** Tue Mar 13, 2012 6:24 pm

FYI: I paid $25 for the entire kit with the standard metric size threaded collars, and now anything will fit b/c I have a common available thread.

The magic PF (wtf is that exactly?) thread and the Fumitomo is USELESS if the factory threads are already damaged. Considering that NONE of the parts shops offer anything in a replacement drain plug OTHER than SAE or Metric, and THEY DO LIST A REPLACEMENT for the CRD... It is highly unusual to expect too many factory threads to still be in good repair or existence. They were too shallow and fragile for even basic shade tree mechanics, to say nothing of dealer or oil change shop gorillas.

WolverineFW · **Posted:** Tue Mar 13, 2012 6:35 pm

Gokeeper wrote:

Sorry for the miss information. Joe is correct the size is odd. I was curriouses so I grabbed my old plug and messured it. Came out as 16.4mm with 1.33mm pitch. That is neither BSW or SAE, basically an oddity. Best to get the Fumoto F-102 (PF-3/8)

In your case and mine use a 41/64 drill or 16.5mm and a 18mm x 1.5 (f-104) fumoto

41/64 isn't too hard to locate, just be prepared to pay,locally mine was $27.00

PF threads are JIS fittings aka Japanese Industrial Standard design, which are very similar to BSPP or British Standard Parallel Pipe. Both are measured in inches, hence the 3/8". PF also indicates a straight thread design acording to the JIS. Since it also requires a gasket for sealing properly, it verifies the straight threads.

Joe Romas · **Posted:** Tue Mar 13, 2012 7:58 pm

Geordi

More then a couple of us replaced the original drain plug with a fomoto valve before the threads were messed up. Plus the original question was "what size is the oil plug" :rockon:

Maybe you should start a poll to see how many don't have a stripped oil pan :BANANA:

EAB · **Joined:** Tue Sep 06, 2011 9:39 pm **Posts:** 141

Joe Romas wrote:

Geordi

More then a couple of us replaced the original drain plug with a fomoto valve before the threads were messed up. Plus the original question was "what size is the oil plug" :rockon:

Maybe you should start a poll to see how many don't have a stripped oil pan :BANANA:

so whats the number for a Fomoto valve and stock threads?

tedder · **Joined:** Thu Sep 15, 2011 7:19 pm **Posts:** 137

Thanks everyone!

I went with the

Gokeeper wrote:

Sorry for the miss information. Joe is correct the size is odd. I was curriouses so I grabbed my old plug and messured it. Came out as 16.4mm with 1.33mm pitch. That is neither BSW or SAE, basically an oddity. Best to get the Fumoto F-102 (PF-3/8)

In your case and mine use a 41/64 drill or 16.5mm and a 18mm x 1.5 (f-104) fumoto

41/64 isn't too hard to locate, just be prepared to pay,locally mine was $27.00

I found all on Amazon at resonable prices. I wasn't too concerned about quality since I'm only using the drill and tap once. :BANANA:

warp2diesel · **Posted:** Tue Mar 13, 2012 11:19 pm

Lots of ways to fix a stripped drain plug that don't leak.
Just Remember!!!
Only Steelers replace the oil pan. :ROTFL:

What ever engineer who picked out the 3/8" X 19TPI British Pipe thread plug for the oil pan, must have a cousin who has an upper management position at CARB. :ROTFL:

OldSkull · **Posted:** Wed Mar 14, 2012 6:10 am

Joe Romas wrote:

Every time this question is asked the same old misinformation pops up.
Anybody who thinks it's 5/8" x 18 tpi get a 5/8" x 18 tpi threading die or nut and try screwing the drain plug in. IT WON"T GO IN.. Some say it's a 3/8" NPT, try that and you'll see the drain plug swims in a female 3/8" NPT fitting.
This engine is made in Italy, what makes anyone think there are SAE fasteners in it :dead:

And it's not 18mm x 1.50 either.

See this thread for the real deal, it's a PF 3/8
viewtopic.php?f=5&t=40736&p=434753#p434753

PERFECTLY RIGHT!
That's why I use a Fumoto F102...It's a PF 3/8

Here the first 2 good link for a thread data charts from Google...
http://mdmetric.com/tech/thddat7.htm
http://www.ring-plug-thread-gages.com/PDChart/G-series-Fine-thread-data.html

tedder · **Joined:** Thu Sep 15, 2011 7:19 pm **Posts:** 137

Just for the record Fumoto does not even make a 5/8 x 18 tread size valve so you can't use that size anyway.

OIL PLUG THREAD SIZE?

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