What are you, some kind of conspiracy nut?

 

 

 

No, i'm not a conspiracy nut.  I'm a qualified motor mechanic who spent 14 years in the Automotive Trade specialising in Suspension, Brakes, Chassis Engineering & Tyres.  Then a client asked if I'd come & work for him as an aircraft mechanic. I specialised in Military Spec rebuilds of various 707 engine components & 747 RR RB211 fuel controllers while simultaneously studying and attaining para-professional qualifications in Production & Mechanical Engineering.  After 18 years the GFC bit me & I was made redundant. Since 2007 I've worked as a preventive maintenance work plan & scheduling specialist in large water assets (2.6million gigalitres) and spend about AUD5 million/pa on maintenance interactions on large pumps, hydraulic systems, etc.

 

So yeah, I haven't a clue.

The reason for the drain/refill plugs is so that if the gearbox springs a leak at any of the major oil seals (input shaft, diff etc.) then the seals can be easily replaced and the box refilled without removing it.

 

Every dealer will sell the fluid in the event that a gearbox has leaked and requires refilling to the correct level. It's expensive because it's excellent oil.

 

Also your point about ATF is totally irrelevant to manual boxes because ATF is pumped and filtered, acts as a viscous shear medium, as a hydraulic oil as well as being expected to splash lubricate the bearings and gears. A manual box only needs splash lubrication which is why the correct level is so important.

 

What are you, some kind of conspiracy nut?

 

 

Be serious, I've worked for numerous racing engine manufacturers and actually know what I'm talking about.

 

I've seen some pretty spectacularly expensive failures and NONE of them were caused by not putting the correct SNAKE OIL in during routine maintenance.

 

An old trade trick to quieten a whining diff or gearbox was to put tractor oil in, it was like TREACLE and even the noisiest diff or gearbox would quieten to the point where you couldn't hear it, however this was done just to sell it because they knew the diff would still fail because the bearings were wearing and no amount of sticky gunge would ever stop that.

 

Additives sell because boys love their cars, additive manufacturers know this and profit wildly from it, they are like girly cosmetics with all kinds of silly pseudo-scientific names and claims, most of them do no harm but they don't do any good either, they're a PLACEBO.

 

I can categorically tell you that manual gearbox oil does not degrade like engine oil, ATF or brake fluid, it's fully synthetic, it's not hygroscopic and will last the entire life of the drivetrain if it is maintained at the correct level. Because it isn't pumped, any metal debris settles to the bottom of the box where it remains in perpetuity doing no harm. Occasionally gearbox oil will turn black and smell horrible, this is due to Sulphide formation where components of the gearbox oil additive pack react with the copper in brass or bronze bushings, it's unpleasant but utterly harmless to your gearbox.

 

Changing your manual gearbox oil will do no harm as long as you use the manufacturer recommended specification, it's just TOTALLY unnecessary and a complete waste of your time and money.

 

You have your views & are entitled to them. I have done the gearbox oil drain on various VAG cars since I first owned one 21yrs ago. Most of the time I have replaced the existing "sealed by factory" fill with VAG stuff from the dealer parts dept. So an exact spec match, no "Snake oil". & In every case the gearbox sounded quieter, & was way smoother on shift feel etc.

 

I did my mates Fabia 1.4MPI with the exact VAG stuff, same again, did my Fabia 1.4 16V with Millers Motorsport version & as per the specs it was stiffer from cold, but when up to temp it was the smoothest gear change I've ever had!

 

Also the viscosity & colour of the factory (old) oils in ALL CASES I would state they were degraded, & used & beyond their best.

 

I could post loads of links on this "placebo" effect as you call it, but as some would be from the oil manufactures themselves you would most probably state "well of course whey would say that they are snake oil salesmen". So I won't bother.

 

However I must, like other mechanics who have experienced the same go & see a shrink about our years of first hand experience as apparently it is all a figment of our imagination................

So no actual information then, no scientific basis for these 'feelings', no real reason why the manufacturer is wrong other than they must be lying to try and steal your money or make your car wear out early?

 

Nothing.

 

Just, we're all wrong and you and your pub pals are right.

 

Ok, I don't care, I'm not trying to sell anything, like I said, it makes no difference, it's your money and your time, spend it however you like.

I have a feeling this could be a bit like gluten free stuff which makes your **** fly off

I feel this could be the same set up here

Must admit, from an engineering point of view I do always like to see facts if they are available.

Going slightly off topic (and apologies for that) but in the sector of the industry I work in, alot of engine and gear box oils are replaced according to condition based sampling. If the oil shows know signs of contamination or deterioration in properties then it stays in until the next scheduled sample (it is slightly more complex than that but that is a high level summary), cost savings and reduction in environemental impact are massive.

Sepulchrave is making a good point I think that there is unfortunately a very heavy commercial aspect to oil changing. I'm not saying this is a hard and fast rule but certainly a valid point.

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Ok, so.........

 

My local garage has quoted me £180 inc VAT labour to remove and re-install a gearbox, £280 for a new clutch at the same time. 

 

Found a GGU VW box on Ebay that is off a Polo for £149. Car had done 89k and he says there are no noises etc and is in good working order and gives a 90 day guarantee.

 

My questions is, it's the right code, so it should be a straight swap yeh? Also Is this a sensible option? Still a used, non refurbished box at the end of the day. Total would come to £330... not too bad I think, but is it worth spending that when there is the potential this gearbox could do the same in 20k or so?

 

cheers

So no actual information then, no scientific basis for these 'feelings', no real reason why the manufacturer is wrong other than they must be lying to try and steal your money or make your car wear out early?

 

Nothing.

 

Just, we're all wrong and you and your pub pals are right.

 

Ok, I don't care, I'm not trying to sell anything, like I said, it makes no difference, it's your money and your time, spend it however you like.

 

As I stated in my post there are various amounts of info on the web, however most of it is either people & mechanics like myself who have drained old oil out & gone "yuck" at the thick /dirty black stuff that comes out, & then filled with new stuff & WOW the difference in feel & noise.........or it is stuff written by people who work in the oil industry, & that info you will dismiss as you stated earlier in your other post that it's done by Snake oil salesmen so of course they will want to sell you anything!

 

Personally gear oil like any other oil has heat stress & load stress, & if I'm blasting around the backroads rally style which means loads of gearchanges, that gear oil gets heat stressed! If I am doing it with a couple of mates in the car as well then load stressed also. I change the oil in the engine every 10,000miles or 1yr (soonest) & that stuff comes out Black! (& that's Mobil 1).............& you want to keep the gearbox oil in for life? I like to change mine to make sure it's in tip-top condition, as I don't want the gearbox to fail due to me "rallying". Also by draining it any metal particulates which will be there in any situation now have the chance to drain out.

 

You say you worked in racing? So if the gear oil is ok did they fill the gearbox & then if they had to repair the box did they just collect the oil every time & re-fill it, as by your statement the oil should last the lifetime of the box.

 

As far as I am concerned for the sake of a bit of effort & a small outlay it makes a huge difference, even the people who test drove my car & bought it couldn't believe how smooth & precise it was for it's age!

 

You & I will differ on this & many other topics, I prefer to spend a bit more money to "make sure" so I can end up not worrying about things later on & can rely on everything in all weather conditions, that can be tyres, batteries of engine oil eg Mobil1 engine oil 0w40 rated, the Fabia doesn't require that but when I had left in outside all day in -20c & colder it started first time & sounded smooth & was responsive. 

 

 

Back on Topic:- to the OP I would not trust someone who states it doesn't make a noise as there in no way of checking & that 90day guarantee, we we all know sods law, day 91 it fails...............get a refurbed one done properly if you plan on keeping the car long term.

So no actual information then, no scientific basis for these 'feelings', no real reason why the manufacturer is wrong other than they must be lying to try and steal your money or make your car wear out early?

 

Nothing.

 

Just, we're all wrong and you and your pub pals are right.

 

Ok, I don't care, I'm not trying to sell anything, like I said, it makes no difference, it's your money and your time, spend it however you like.

 

 

Going slightly off topic (and apologies for that) but in the sector of the industry I work in, alot of engine and gear box oils are replaced according to condition based sampling. If the oil shows know signs of contamination or deterioration in properties then it stays in until the next scheduled sample (it is slightly more complex than that but that is a high level summary), cost savings and reduction in environemental impact are massive.

 

 

I did mention to the OP he could do a UOA but when i did my last gearbox oil change on the Octy, the oil cost me $27 and the firm we use for UOA charges $30.  So why would you pay $30 for somebody to tell you that you need / don't need to spend $27?  Sure, if the gearbox oil change was $400, you'd do UOA first.  I do UOA on our hydraulic gate systems every 12 months because the change cost is $600 and there's $100k worth of hydraulics hanging off them and if they don't work when needed then there's a high risk of dam failure / flooding / dead people but on a simple gearbox you just get in and do it.

 

I did UOA on the 504.00 spec oil  at 15,000km and it came out perfect but it's amazing how many people say that the oil should be changed at 5,000km.  What do you do?

Is a UOA the same as DIY ?

 

DB.

Is a UOA the same as DIY ?

DB.

Used Oil Analysis

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