which oil for 6 speed box
Discussion
I stick with comma manual gear oil EP75W80 plus GL4.
Get it from your local Halfords. I have used this in my 6 speed for the last 10 years. No problems.
It is a mineral base, the same type as Caterham fit. I have tried semi-syn but fine the box is happy with the mineral.
There are a few posts on the web that mtl is too slippery for the box’s synchros. Much view and discussion on this point.
Get it from your local Halfords. I have used this in my 6 speed for the last 10 years. No problems.
It is a mineral base, the same type as Caterham fit. I have tried semi-syn but fine the box is happy with the mineral.
There are a few posts on the web that mtl is too slippery for the box’s synchros. Much view and discussion on this point.
Edited by viper blue on Sunday 16th September 18:35
viper blue said:
I stick with comma manual gear oil EP75W80 plus GL4.
Get it from your local Halfords. I have used this in my 6 speed for the last 10 years. No problems.
It is a mineral base, the same type as Caterham fit. I have tried semi-syn but fine the box is happy with the mineral.
There are a few posts on the web that mtl is too slippery for the box’s synchros. Much view and discussion on this point.
They do an "NS" (non slip) version. I use this in my rebuilt 1960's Alfa Romeo box (with modern synchros) and the standard MTL product in my Caterham 6sp box. Get it from your local Halfords. I have used this in my 6 speed for the last 10 years. No problems.
It is a mineral base, the same type as Caterham fit. I have tried semi-syn but fine the box is happy with the mineral.
There are a few posts on the web that mtl is too slippery for the box’s synchros. Much view and discussion on this point.
Edited by viper blue on Sunday 16th September 18:35
I'd speak to Phil @ Road and Race Transmissions if you want chapter and verse on the Caterham box, it's foibles and the recommended oil.
analog_me said:
Thank you,
As per my internet search the filling point is on the side and needs to be filled in until it starts to overflow but how much is this in liters?
Furthermore is there a bottom drain on the box to remove the old oil ?
Yes, there is a bottom drain and from memory you’ll get about 1.8 L or so in. The MTL comes in US quarts, about .95 LitresAs per my internet search the filling point is on the side and needs to be filled in until it starts to overflow but how much is this in liters?
Furthermore is there a bottom drain on the box to remove the old oil ?
I cut down an Allen key to fit in the level plug, which I turn with a 10mm spanner.
I pump the oil in with a Sealey Mini Pump. It’s pretty straightforward.
MTL certainly works well but needs a caveat in terms of gearbox wear. It works by increasing friction between the synchro cone and rings - essentially removing any polishing of the synchro surface. But that results in faster wear, and wear rate that may be important to you. I found using MTL to 'rejuvenate' the box every now and then, and then changing to a conventional GL4 oil gave the best of both worlds.
Mine previously had MTL but I started to question whether the noise was doing the gearbox any good ... swapped to a regular GL4 oil and the box runs much quieter. When cold there's a slight drag going into 2nd but this disappears within half a mile of use, absolutely no difference in shifting when warm. My car's predominantly road use with an occasional track day, I've decided a normal gear oil is more appropriate for my use.
V7SLR said:
Mine previously had MTL but I started to question whether the noise was doing the gearbox any good ... swapped to a regular GL4 oil and the box runs much quieter. When cold there's a slight drag going into 2nd but this disappears within half a mile of use, absolutely no difference in shifting when warm. My car's predominantly road use with an occasional track day, I've decided a normal gear oil is more appropriate for my use.
Why the reference to GL4? MTL is GL4. It’s odd how different users have different perceptions. I’m not aware of any change in noise, though the gearbox is pretty quiet in any case.
I did perceive an improvement in the smoothness of change when I started using MTL but haven’t ever noticed any ‘drag’ when cold, whichever oil. Having said that I always go slowly through the box until it’s warm so maybe I wouldn’t.
As I was looking into how to best replace the grearbox oil I discovered since the last two years and 8000 miles I own the car a plug is missing from the gear box driver side above and behind the speedometer pickup point, close to the gear lever. Do you know that this is?
It is in the place the red plug is located in the caterham website showing the 6speed gearbox.
https://caterhamparts.co.uk/gearboxes/5204-gearbox...
It is in the place the red plug is located in the caterham website showing the 6speed gearbox.
https://caterhamparts.co.uk/gearboxes/5204-gearbox...
Edited by analog_me on Thursday 11th October 21:17
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