Gearbox additive info

[mr bump]

Im wanting to use a gearbox additive for my dogleg 5 speed in my E9, ive just changed the clutch and I drained out the LSD oil ive always ran in every manual gearbox ive ever owned, reason being it looks after the old gearboxs better than a standard oil imo.
Ive noticed that with a thick mineral oil, gear changes were quiet sluggish and difficult at times, so I filled the box up now with a fully synthetic atf oil and the gear changes are now effortless even when cold, it realy does suit the dogleg boxs.
But, now heres the but......its a little bit noisy but only in low revs. As soon as the revs increase the noise goes.
So im after a gearbox additive what will quiet it down a bit.
Has anyone used these before? Or can recommend one to me as ive looked on all the online sites and shops and there are thousends of types and makes.

 

[Polariscsl]

I tend to steer clear of additives as all you are doing is effectively changing the grade - you might as well just try a different oil. Noises in 5 speed tend to be lay shaft bearings and I'm not sure which oil is best to 'mask' that.
I run Redline MTL in mine and it is perfect....but it is newly rebuilt.

 

[deQuincey]

aditives, the paradise of the lost souls...
i would not play the role of a chemist adding this and the other to an already proven formula, moreover when you certainly know that it might be secondary effects in the new forumula created by adding the aditive, you willl never know what is present now in the commercial oil, then you will add something that you again will not know its components,...., thus the probability of catastrophic results is high
IMHO, obviously !

 

[DougE]

Redline MTL is the way to go on the trannsmission, I think it's wise to use a friction modifier in the LSD. Redline offers a friction modifer product for the LSD#80301.

 

[Bert Poliakoff]

+1 on Redline

 

[sfdon]

Do yourself a favor and read the back of a redline tranny fluid bottle.
The explanation is remarkably clear.

More info:

Popular for BMW, Honda and Acura, Ford Focus, late-model Mini Cooper, Land Rover/Range Rover
Safe for brass synchros, as it lacks the reactive sulfurs found in most GL-5 oils that cause damage
Offers quicker shifts, perfect synchronizer coefficient of friction
Eliminates notchy shifting, even when cold
High performance gear protection and longer synchro life
Satisfies the gear oil viscosity requirements of 75W, 80W, and motor oil viscosities of SAE 30, 10W30, and 5W30
Recommended for GL-1, GL-3, and GL-4 applications as well as where most special synchromesh fluids are specified

 

[jmackro]

its a little bit noisy but only in low revs. As soon as the revs increase the noise goes.

I suspect the noise doesn't go anywhere - the engine and wind noise just build with revs and speed to the point where you can't hear the transmission howl.

As others have said, Redline manual transmission oil is designed by smart people to do that specific job. ATF + an additive is black magic.