I understand the need for fluid in the rear differential to be for wet brakes, however can I substitute standard 80-140 in the front differential and final drives??
I would not sub the heavy weight oil for the recommended Hytran Ultra in the front differential. The outer planetaries do use a special oil which is a heavier oil than Hytran Ultra and used in Case's transmissions in other applications. I personally would stick with Case's recommendations. These companies do extensive studies and rigorous testing to determine which oils give the best protection from wear. Having worked for a Case dealership for going on 50 years I can attest to the advantages of staying with Case products, I have worked through some real disasters where people have chosen not to do so. If you think that oil is expensive wait till you start replacing hard parts. Mel
I don't want to confuse things - but over here I have only ever seen gear oil in the front axles of any Case hoe from D to SR. Maybe we have a different spec because of our climate? Here's a pic from 580SLE manual. I'm not doubting what mel is saying, - there is obviously a difference from US to AU.......
Interesting alrman, I just looked at an M a day ago and the spec on the side decal was HTU in the centerbowl and tf (Case's wet brake 90 wt)---same oil as the wet brake k's with the prior to series 3 tranny took---- in the front planetaries. I would guess that it is a climate related issue but before those hoes the L's were the first to use HTU straight across the front end. It would be interesting to get others from different areas to put the recommendations that their servicing decal states. Mel
I'm pretty sure 75w-90 synthetic gear oil would be the best choice for front drive axle and hubs. There isn't any brakes In the front axle is there? I don't believe so on my 580sk anyways. I plan on replacing my front axle and hub fluid this spring with mobil 75w-90 gear oil and my rear transaxle with ConocoPhillips version of hytran ultra.