Preventive Maintenance

Hi,
I just performed full maintenance procedure to my Brushless XT8 Truggy.
I replaced the oils on the Diff’s, filled up missing oil in the shocks and checked the bearings condition. Last time I did that was 3 month ago – total of 5 hours of run time on the track.
No major issue found but I did noticed that the oil in the diff’s become very thick and dirty.
In addition to the above I’m cleaning my Truggy after every session on the track, looking for loose screws and cracked/broken parts.

What are the maintenance intervals for you guys? 5 hours between preventive maintenance is good enough?