salimshah

For DIYers:

Here are the risks ...

Always use the torque wrench with proper settings. [If you dont, you can potentially ruin the pan (first) and or the drain bolt second]. You can spring a leak even with a new crush washer.

If you do not use a new crush washer, you can develop a leak ... typically it is not a gusher. [no one can claim you will, and no one can say after how many usages you will]. Note probability of a leak is higher if you have 2 or more crush washers ... so make sure you remove the old one. [for me discard].


If it matters, I for one always change the crush washers.... [why... I grew up with diesel car and the fuel delivery system would fail with a minute (undetectable) air leak ... was stranded in a cold winter night for a tiny leak in 0.001cent (currency exchange) part.]


[We are discussing habits and patterns here which are based in personal experience.]
Salim

rx300s415

Just curious what should the drain plug bolt be torqued to exactly?

bob2200

33 ft-lbs (45 newton-meters, 460 kg-cm) [ref. pg. LU-4, repair manual]

Pocket Tre

hey bob!!!

I am looking for a good pdf copy of the manual.

Do you have access to one?

Juan

bob2200

You can find paper copies of the Repair Manual coming up on eBay sometimes. I got mine when the RX300 was new.

I got a PDF-on-CD repair manual on eBay a few years ago, and it is not the same as the official version. I've always found the PDF CD impossible to use. There is a search function, but no index.

So, I'd recommend you get a paper copy Lexus RX300 Repair Manual off of eBay. Or, maybe this eBay CD is different http://cgi.ebay.com/ebaymotors/1998-...spagenameZWDVW

salimshah

Male and female threads have a gap in them. That is how you can spin them on each other with minimal effort.

In scientific terms all materials have elasticity (where they stretch and tend to return back to their original form) this makes metals more elastic than say rubber. All materials have a certain point at which they become permanently deformed .. they do not come back to their original state.

When you torque a nut or bolt, the bolt gets stretched by the groves. The higher the torque the binding force (squeeze) is higher.

Now lets discuss the gaskets and washers ... if you squeeze them too much they may reach their limit and become permanently deformed and no longer have the pliability to from a seal.

The threads of the nut, bolt, pan, thread etc can also be stretched so much that they strip.

The binding force needs to be enough to prevent unthreading (by vibration etc) and not too much to reach the limit of the gasket, threads etc.

Note: The torque based stretch is on the side of the threads. That still leaves a channel for oil leak.

Salim
ps ... I misunderstood the question what vs why. What has been answered.

Salim

Pocket Tre

I think i will try the paper manual.

My pdf file is not user friendly. So maybe we have the same cd lol

TunedRX300

I am with Lexmex, it is not so complicated, the crush washer's main function is to stop the leak.
As long as it holds up the oil and allow the owner to loosen the drain plug, who cares about what brand (and the need for the washer if end goals are achieved)?

code58

Bob- I am in complete agreement with proper maintenance- for me that means 3k oil and filter changes (generally only orig. eq. filters) and 25k trans. changes (complete change by fill and run, fill and run). I am meticulous about maintenance and routinely checking my vehicles over. I did own 2 planes and did some of my own work under the direction and sign-off of a very fine A/C mech. I feel (from experience) that Toyota/Lexus builds some very fine cars out of some very fine parts and that some of those parts aren't close to their end of life cycle when T/L recommends replacing them. I replaced my DIL's RX timing belt, spark plugs, a/f sensors and numerous other parts at 97k. There were extensuating reasons for SOME of this but most of it because of Lexus recommended standards. I had reason to remove the timing belt at 120k searching for a 1/2 second squal at start after I had replaced the alt./comp. belt. (I had already checked the tension and it was correct). I checked the water pump bearing, idler pulley bearing and the tensioner pulley bearing and all were as smooth as glass (they had never been changed and I did not replace them at 97k despite Lexus recommended change. Those bearings are massive!) I checked the gap on the original plugs at 97k when I changed them and it was still factory gap. I cleaned them off with a small wire brush and a small amount of lacq. thin. and they were almost like new! There are other Fact. recom. that I feel are excessive, especially for someone like me who is used to checking things frequently- and I do a lot of routine maintenance that is not needed- I'm not tight by any means, but I have a hard time taking rad. hoses and fan belts off that look like new just because their B'day has arrived. I'm not arguing with T/L or anyone else on these matters- I understand the reasons why they do it, I just don't always agree with it. By the way, the squell was the new Premium Dayco belt that I had put on. I took it of, put the old belt on (still in very nice shape at 120k) and the problem was gone.

code58

Hi Pocket Tre- I absolutely respect and agree with the reasons for the standards in A/C work. Pretty hard to pull over to the side of the sky if it conks out. I believe in using a torque wrench (I have 5 different ones- I'm a tool freak), but in automotive work, especially in things like changing oil, I have never used 1. I have a very good feel for the amount of torque and do not feel it is necessary on a pan plug. (would never feel that way about a plane) In all the years that I worked in automotive it has only been in more recent years that anyone suggested replacing a pan plug washer unless it was leaking- they were lifetime unless they were overtightened. That is why I prefer copper- it is soft and seals well for a long time if not for life. Not a crush but rather soft solid washer. It will not distort unless overtightened. I have never in my life believed in cutting corners- in aircraft not torqueing every single fastner is cutting corners- in automotive for an experienced mechanic, you know when to and when you don't have to. I would not think of torqueing alternator bolts for example, though torque specs exist for them. My hat's off to you for being a meticulous A/C mechanic. Roger

Pocket Tre

I am ok with your response, however what happens when you have to replace a..... let's say something like a tie rod or a steering link where the nut has a torque value and a cotterpin? Do you pass on the torque because it has a cotter pin? Do you reuse the cotter pin?

To me, that is also a little extreme for an example, but why is the requirement there?

I rather know and feel secure that my wheels will not fall off at 65 mph on the highway because I know I replaced the only ONCE used cotter pin (.50c)

Yes, nobody can compare the difference of auto and aviation maint. That was not my intent. My intent is to say that regardless of what you are doing maintenance on you should follow the book.

Bicycle is a good example. Do you pressure the tires to the proper value or just to how it feels?

I know..........

You all hate me for this, I do not want to force MY maintenance practices upon you or any one else. Believe me that is not what I am doing.

It is only my opinion. You do the maintenance whichever way you feel is better.

Believe me I do not do everything correctly. We all make mistakes.

Funny note( I did not torque my eng oil filter last time)

AlexusAnja

The initial question was more to the extent of "what is the rubbery material" that is on the oil plug area... but has turned into should you replace the washer or not. I know that there are certain maintenance items which are excessive or not necessary, but whether the washer is required each change or not, it's less than $1.50/piece, so isn't the cost a moot point? I would be more worried about getting the right filter than a $1 item.

I've been DIY oil change on all my vehicles since 1985 and I have never used a torque wrench, but have replaced the washer each change and have never had any leaks from that area ever. I just tighten to "touch point" and then give it an extra 1/4 turn perhaps.

salimshah

Torque wrench is a must have tool.

Once you have it and not use it is like ...

You have a folded umbrella in hand and it is raining on you.

Salim

code58

Pocket Tre- Your response gave me a good chuckle because I have known quite a few A/C mech.'s. As a matter of fact my deceased half-brother spent his life in the profession. No, PT, I own a more than adequate supply of cotter pins and I do use them- I have never reused a cotter pin unless it was an emergency. I do torque whenever I feel it is necessary (with 5 torque wrenches shame on me if I don't), but still don't feel it's necessary to torque
alt. bolts (or my oil filter). LOL May all A/C mechanics be as meticulous as you! Have a great life PT!

Pocket Tre

The only reason you feel this way is because you can pull over to the side of the road if any component fail.

I, on the other hand have less chance of having a component fail because I follow the book for ALL maintenance.

Yes, if you fail to torque any of your components on your vehicle, shame on you. You have them torque wrenches and still refuse to use them. That is your prerogative, however, they must look very nice and clean on their display cases.

Just think it over when you strip a nut or better yet snap a bolt and have to tap a new set of threads with your torque wrench sitting just paces away from you.


Torque wrenches is a must, yes, but what good do they do sitting inside the toolbox and not being used.

Salimshah could not say it better. Great post Salim