New member

Re: D5N XL Transmission Fluid Question

I appreciate the answer. I wasn't sure much was added but just asked and he said around a gallon, so approximately 4 liters. 


Just getting the answer to that question makes me feel a little better.

Regular Contributor

Re: D5N XL Transmission Fluid Question

You do not state how much HYDO oil was added to the transmission system. The transmission powertrain oil system capacity is 122 Litres. The transmission requires transmission drivetrain oil which is a different specification to the hydraulic system which requires the Cat HYDO oil. Hydraulic oil does not have the additive chemistry required for the powershift transmission clutches. Doubt if any harm has occurred ( subject to how much oil was added) but recommend replacing oil as a precaution.

New member

D5N XL Transmission Fluid Question

Let me start by saying I purchased a 2005 D5N XL last year. It is my first dozer and I am a beginner to say the least. 


I have the machine rented to a guy who has experience operating dozers for a construction company, but they had their own maintenance folks and he never did that part.


When checking the dozer, he thought the hydraulic fluid was low, so he added some. The problem is, he was checking the transmission fluid level and added hydraulic fluid to the transmission. He then ran the machine for several hours until I showed up and he showed me where he had checked the fluid and we discovered his mistake.


The fluid he used was CAT HYDO ADV 10 weight (CAT part number 3096931). I have done extensive web research and can't seem to find out what I need to know. 


First off, will that fluid hurt the transmission or is that an accepted use for it? And, secondly, if it may pose a problem, what do we need to do next?


Thank you for your time and for understanding that I'm definitely new at this.