Oil Sump Plug

Before Christmas I purchased a magnetic oil drain plug from a company stateside (i'm UK). When I came to change the oil, I found the plug I received was of a smaller diameter to what I have, so I ended up re-installing my old plug. Now it is "that time again" I thought I should ask if there is any difference in size of oil sump plugs between Renix & Chrysler?

I'm not sure whether I ordered the wrong one, that is, my 1988 Renix 4litre "could" be fitted with a later sump or the guy just sent me the wrong part.


Thanks in advance
__________________________________________________
1988 Cherokee Laredo 4Litre, 4WD, Auto, Cali-Spec'

I'd think it possible (albeit a bit unlikely.) Are you able to measure the thing? All that should be required is nominal diameter and thread pitch (should be either 1/2"-13, 1/2"-20, or M12-1.75. A caliper and a thread gage should suffice.)

Just for reference, in case you don't have a thread gage, 1/2"-13 is 13 threads per inch, 1/2"-20 is 20 threads per inch while M12-1.75 is 1.75mm between threads. Sorry, you probably already knew that. But 12MM is only slightly smaller than 1/2". 12mm = .472", so that only about .030" smaller. Are you sure it's not a Whitworth thread? (LOL) To quote from my old Norton manual "taking spanner twixt thumb and forefinger".

I didn't think there were any outfits that weren't British using Whitworth threads, with the possible exception of older Mauser actions!

I wonder if I still have that set of Whitworth wrenches...? It's odd that the Whitworth thread profile is actually better from an engineering sense, than the UNC/UNF/ISO 60-degree, but the Unified caught on because "everyone does it."

It's an example of "What is Popular is not always Right." Kinda like how NATO uses the 9x19 - even though the .45ACP has been proven time and again to be more effective (face it - if the 9m/m were worth a damn, why then are there so many variants of it? 9x17/.380ACP, 9x18 Makarov, 9x19 Parabellum/Luger, 9x20, 9x21 Winchester, 9x23 Largo, 9x23, ... And everything from 9x19 on down seems to compare only marginally with the .38 Special - which the 9x19 was rejected as a replacement for!)

I'm with that old school shit. 45ACP all the way. And 30-06. Beretta vs. Colt. As far as that goes, I'm so old school that I prefer a revolver for plinking. Problem is, once you find something you like (in life), they quit making it. Maybe like XJ's.

winterbeater said:

I'm with that old school shit. 45ACP all the way. And 30-06. Beretta vs. Colt. As far as that goes, I'm so old school that I prefer a revolver for plinking. Problem is, once you find something you like (in life), they quit making it. Maybe like XJ's.

Click to expand...

Yeah, I keep running into that.

Rifles? I've shot everything out to the .458 Lott and .460 Weatherby (and the .50 BMG - but the Barrett M82A1 has such a damned good muzzle brake...) so the .30-06 doesn't bother me. I was shooting 1000-yard with it when I was a teenager.

The .308/7.62x51 (?) is a good compromise - I can see the desire to be able to carry more ammunition. But, make sure that ammo is still effective - the 5.56x45 isn't a good compromise there. Even the 7.62x39 Russian is an improvement, and the 7.62x54R wasn't bad at all.

But, I digress. I'm fairly sure he'll find that his sump plug is a Unified thread pattern, I'm just not sure if it's going to be SAE (inch) or ISO (metric.) I'd be mildly surprised if it weren't SAE, but only mildly...

Lee enfield 303 all the way!! Nowadays it appears the price is the most important issue deciding how good something is. The 9mm glock, dirt cheap when it first come out, no-one wanted it, they simply couldnt shift them. So some genius decided to simply triple the price and hey presto. All of a sudden its being sold all over the world. Superoo where in london? Ive got a new spare from the dealership that fits my 97 you can have but its not magnetic so not sure youll want it.

How in god's name did we get onto round size???:looney:

With the .303 you can be pretty sure the bugger isn't getting up again.

I'm in North London dunbad, that's a very nice offer.

So I take it there is no difference? Just that when I had come across standard oem on teamcherokee for example, they'd stated different types for renix and later, and I know it is impossible to get anything "renix" in the UK as they were never sold across here, and I'm not sure whether previous owners had updated the sump to a later model. My head must be as it has the later rocker cover...

Do you ever pass westminster? If so shoot me a pm and ill take it to work so you can pick it up but i dont know if it will fit 100 percent.

SuperRoo said:

How in god's name did we get onto round size???:looney:

With the .303 you can be pretty sure the bugger isn't getting up again.

I'm in North London dunbad, that's a very nice offer.

So I take it there is no difference? Just that when I had come across standard oem on teamcherokee for example, they'd stated different types for renix and later, and I know it is impossible to get anything "renix" in the UK as they were never sold across here, and I'm not sure whether previous owners had updated the sump to a later model. My head must be as it has the later rocker cover...

Click to expand...

Yah - a .303 is in the same league as our .30-06, and I've got great faith in the -06 round (for short-range stopping power, seat the bullets backwards if you roll your own. Downright deadly against charging boar, I've found - and usefully accurate to 75-100 yards.) Although I do like the various Enfield rifles - the only flaw is that they don't make left-handed variants (bugger!)

And I don't believe that the rocker cover is any indication of cylinder head vintage, although I could be wrong (I haven't checked.) I don't know if the later stamped covers will fit in place of the earlier cast aluminum jobs, or vice versa. Look for a four-digit cast-in raised number in between the #3 and #4 exhaust ports on the manifold side of the head (outside the rocker cover) to verify cylinder head vintage:

2686 = 1987-1990 (RENIX)
7120 = 1991-1995 (OBD-I)
0630 = 1996-1999 (OBD-II, Distributor-based Ignition)
0331 = 1999-2007 (OBD-II, COP/DIS Ignition)

And, it still sounds as though measuring the plug directly is going to be your best bet. As you say, a later sump may have been put on (or an overseas-production sump, which could use an ISO plug instead of SAE, or...) and you'll just need to work it out with any doubt at all.

Once you know the size, you can probably find something locally that will work - which will save you ordering from overseas or any other such headache. I'm fairly sure you can find SAE/UNC/UNF-threaded items over there, as there are (I'm sure) enthusiasts who restore vehicles using standard "inch" threads - as well as the old Whitworth stuff...

Some bloke could have stripped out the original and tapped it to fit a Morris or Austin or anything else. The new one you ordered is smaller. So maybe someone tapped it out bigger after they buggered up the hole. You mates must have general auto parts stores like we do, where they carry all brands of aftermarket parts. It would be interesting to take it in there and see what they could match it up with.

Thanks guys for all your feedback.
Dunbad, I may hold off with your kind offer for the moment, I'll have to do a bit more investigating as I've never seen another cherokee sump plug to compare. As for the rocker cover 5-90, I was under the illusion that the later one didn't fit the renix, but I could be wrong...wouldn't be the first time:confused1 As for parts stores winterbeater, they have nothing on the guys you have across the pond, gees even downunder is better kitted out with its variety of auto chain stores. I've been praying for over 10 years (its been that long since I came here) for an American auto chain store to open up and give us value and a HUGE selection, the nearest we're getting is BestBuy next year which is opening up across the UK...maybe good for car stereos, have to wait and see