Gearbox Additives

[hatman]

It may be no more than the march of time/evolution creating a non-level playing field but the gearbox in my S4 always feels irksomely notchy after driving a modern car (my wife's Toyota Yaris for example, which has the silkiest lever-movement that I've ever experienced in any car). Was wondering if the Lotus box could be 'silked up' a bit by the addition of Molyslip, Lucas Oil Stabilizer or any of the other snake oils for sale out there. Any thoughts/experiences/recommendations?

[Matt7c]

Fortunately, I quite like the feel of my S2 gearbox, which is a tad notchy, but in a satisfyingly firm way. My other car has an auto, so I don't notice the difference. However, as a general comment on gearbox additives, I rate Molyslip. Fairly new to Lotus, I have a long history with Land Rovers, which have serious gearbox wear issues. I always found that Molyslip improved the feel of both the gearboxes and made them marginally quieter, although it took more than a week for the effects to be noticeable; the same was true of all 3 differentials. On reflection, the Lotus transmission is satisfyingly simple...

[steveww]

Compared to modern gearboxes the old Ford box can feel a bit notchy. However it may be that the synchro rings are getting worn, worst case. When was the gearbox oil last changed? I did mine last winter and it really improved the gearchange. Oh while you are at it change the oil in the diff as well

[rgh0]

Redline MTL gearoil is the best I have used and will speed up the change and lighten the notchiness in any gearbox. However the Ford box is pretty slick even by modern standards and if significantly notchy it suggestz it may need a rebuild.

Rohan

[types26/36]

I am not a believer in the use of additives in a gearbox, syncro rings work on a principle of friction and the use of a substance designed to eliminate friction must lessen their action.
I think the correct oil or the modern oils designed for gearboxes should be used or a rebuild is called for.
I have heard that adding ATF (automatic Trans Fluid) can improve the gearchange but I am NOT commending it as I have not tried it and do not know what its long term effects would be.
Brian

[Matt7c]

<!--QuoteBegin-types26/36/74+May 19 2005, 10:13 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (types26/36/74 @ May 19 2005, 10:13 AM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> I have heard that adding ATF (automatic Trans Fluid) can improve the gearchange [/quote]
This was a Land Rover issue for many years and became official factory policy for a while in the 90's. The Discovery 1 main gearbox was originally filled with MTF, but then the advice changed to use ATF instead. It was thought to reduce wear...except that it didn't, so now they've gone back to MTF. I had ATF in mine for quite a while and it wasn't a problem. I have the recommened gear oil in the Lotus (left over from my Landy diffs, I think).

Regarding the friction issue, this, like most things, isn't black or white. Sure, the gearbox needs friction, but not to the extent that it wears the cogs down and you get backlash (a real issue for Land Rover, if not Lotus). So there is a happy medium designed into the box. Additives (if they are of any use at all, which is always a moot point based on opinion and sometimes observation) simply try to re-establish that happy medium. The idea that they might diminish friction to the extent that the performance of the box suffers would surely be over-stating their effectiveness by quite some measure. They're not nearly as good as they claim to be, although I'd still use Molyslip in a worn box.

[types26/36]

<!--QuoteBegin-Matt7c+May 20 2005, 05:10 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Matt7c @ May 20 2005, 05:10 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin-->
They're not nearly as good as they claim to be, [/quote]
Then why use them?

It may or not be relavant but in the 70's VW had auto transmissions in type 2, 3's and 4's that had ATF in the auto part and EP oil in the diff section, the seals between would leak and ATF ended up in the diff causing major damage.I realize this is not a direct comparison as the diff had hypoid gears but it does show what mixing oils can do.
I am not aware that any manufacturer recommends the use of additives in gearboxes and some expressly forbid it, their use would invalidate the warranty. I wonder why??
The recommended oil is obviously compatible with all the components including the bronze syncro rings giving the required amount of lubrication and friction, by adding a "witches brew" it must change the characteristics of the oil.
Brian

[Matt7c]

<!--QuoteBegin-types26/36/74+May 20 2005, 06:46 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (types26/36/74 @ May 20 2005, 06:46 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> I am not aware that any manufacturer recommends the use of additives in gearboxes and some expressly forbid it, their use would invalidate the warranty. I wonder why?? [/quote]
What, a Lotus owner who believes that the manufacturers advice is always right????

Hey, I'm not gonna argue over this 'cos its a matter of opinion and I fully respect your belief that they're worthless. Indeed, I don't have any in my Lotus box at the moment. But to answer your question directly, I discerned a noticeable improvement in the noise and feel of the boxes I have used Molyslip in. That's why I used it.

The issue of warranty invalidations is an entirely separate issue. They want you to take your new car back to the dealer for repairs and service. Thats all.