Deodorizing Gear Lubricants

Straight mineral oils should have no offensive odor. Lubricants containing EP agents will  often  have odors which  are not  too pleasant. However, when in an  enclosed gear case  this will  not  be  particularly  noticeable  unless the  operating  temperature is high. If a problem of this  nature is encountered, the  first  step will be to  see if addition of another  odoriferous substance will cover up the first  scent. Thus, pine oil might serve for this purpose. Addition of chemicals which might  change  the  odor of EP lubricants  should  be made  with  caution because  they  might  interfere  with  the EP value  of the  composition.

Odor Control Agents

In general there has been no apparent  attempt  to cover up the odors  of gear  oils  which  arise  from EP  additives. Occasionally pine oil or pine tar will be detected in lubricants designed for exposed gears. Sulfur  compounds  perhaps  have  the most  disagreeable  odor  of any additives  and  consequently  Jonach^46  suggested  treating  such  agents  with  lead  peroxide  to  react  with  any  free hydrogen  sulfide  which might  be  present.