Oiling Trunions

[AGC]

Hi All

Quick piece of advice please... Im about to oil the front trunions on my spitfire and have noticed that they have been previously greased. My question is should I remove the grease or just oil over it. Also would Hypoil 80/90 be ok

Thanks

 

Andrew

[sparky_spit]

I would advise removing the grease first.  Generally (although there will be some rare exceptions no doubt) oil and grease will not mix with each other and so you won't get oil into all areas of the trunnion threads unless you remove the grease first. EP80/90 Hypoid will be fine.

[glang]

First Hypoid 80/90 is perfect.

Second if you dont clean out the old grease you cant be sure that the trunnion is filled with oil (ie the load bearing thread is sitting in a cup of oil). I say this because as you pump in the oil it will overflow out of the top of the trunning past the rubber seal but with grease in there, taking up space, it could come out directly so you think its full of oil when it isnt.

I suppose the oil will tend to gradually dissolve the grease and after repeated fill ups you'll end up with pretty much just oil in there. However dismantling the trunnions to clean the grease out does also give the opportunity to inspect the steel threads for corrosion and cracks (they are known to break off catastrophically) so giving you peace of mind.....

[AGC]

Thanks for the replies and advice