Engine, diff and gearbox oil...

Engine, diff and gearbox oil...

Author
Discussion

Legend83

Original Poster:

9,947 posts

221 months

Friday 29th January 2010
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Hi all, I usually put Fuchs Supersynth 5w-40 in my '5 on the recommendation of Opieoilman.

What diff and gearbox oil should I use / would you recommend? Planning on giving her a proper flush out this spring.

Cheers,

L83

dylan0451

1,040 posts

190 months

Friday 29th January 2010
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i was recently talking to opieoils over the phone a few weeks ago, for the gearbox, i mentioned it shifts a bit naff when cool but perfect when hot and they recommended i not use the redline MTL that i've had in there and try redline MT90 - haven't put it in yet so can't comment.

for the diff, they recommended silkolene boa 90LS - apparently fully synth oils in diffs tend to bring out the noise and harshness, hence the boa 90LS is mineral based and supposed to be quieter. was told to change it anually if the car spends a lot of time on track.

for the engine, when i bought my car it was being run on a 5w oil. when i changed to a 0w the cold start clatter of the valvetrain which lasteda good 10-20 seconds stopped immediately - i'm using mobil 1 0w-40

Gizmo!

18,150 posts

208 months

Friday 29th January 2010
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Is it easy to replace the diff oil? Mine's not the quietest and it sound like the sort of thing that a reasonably-incompetent person might do on a spannery afternoon...

Munter

31,319 posts

240 months

Friday 29th January 2010
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Gizmo! said:
Is it easy to replace the diff oil? Mine's not the quietest and it sound like the sort of thing that a reasonably-incompetent person might do on a spannery afternoon...
Yes very simple instructions.

Car must be level.

Undo the filling bolt (if you can't undo this you definitely do not want to drain the oil).

Undo the drain bolt.

Watch oil drain out, have cup of tea, play with wife etc.

Re fit drain bolt.

Put new oil into filling hole until oil level is level with bottom of hole. Allow excess to drain if needs be.

Re fit filling bolt.

The tricky part is finding something to push oil through a bolt hole, so I got a garage to do it as part of a service. boxedin

MX-5 Lazza

7,952 posts

218 months

Friday 29th January 2010
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Before undoing the drain or filler plugs make sure you have the sockets for both - they aren't the same size. I can't remember what size is needed, something like 23mm & 24mm.

Remove the fill plug before the drain plug (you don't want to drain the oil then find that you can't remove the fill plug wink)

Legend83

Original Poster:

9,947 posts

221 months

Friday 29th January 2010
quotequote all
dylan0451 said:
for the diff, they recommended silkolene boa 90LS - apparently fully synth oils in diffs tend to bring out the noise and harshness, hence the boa 90LS is mineral based and supposed to be quieter. was told to change it anually if the car spends a lot of time on track.
What if you don't have an LSD?

MX-5 Lazza

7,952 posts

218 months

Friday 29th January 2010
quotequote all
Munter said:
The tricky part is finding something to push oil through a bolt hole....
I bought a cheap bulb-pump from a motor-factors. It's actually designed to pump fuel but it works well with oil too.

Legend83

Original Poster:

9,947 posts

221 months

Friday 29th January 2010
quotequote all
MX-5 Lazza said:
Before undoing the drain or filler plugs make sure you have the sockets for both - they aren't the same size. I can't remember what size is needed, something like 23mm & 24mm.

Remove the fill plug before the drain plug (you don't want to drain the oil then find that you can't remove the fill plug wink)
Cheers for the tips!

ETA - is it possible to do the diff change without putting the car on ramps? I only have 2 axle stands....

Edited by Legend83 on Friday 29th January 13:25

dylan0451

1,040 posts

190 months

Friday 29th January 2010
quotequote all
Legend83 said:
What if you don't have an LSD?
won't do any harm or in any way be inappropriate both open and lsd have the same main gears

Legend83 said:
ETA - is it possible to do the diff change without putting the car on ramps? I only have 2 axle stands....

i can do mine with no jacking on a flat surface, however a fine tooth ratchet and a jack bar on the end is needed as you have barely any leverage or space while on your back - i put a trolley jack under the diff, then with the front wheels chocked jacked it up so as i had more room to crack the filler and drain bolts. then drop the car back down so it's level and drain the oil, refit the drain bolt finger tight, pump the new oil in, then you should be able to tighten up both bolts with a ratchet without bothering to jack the car again

might be worth ordering a couple of new washers when you do this job, though not strictly necessary