Farm Equipment - 8070 FWA

Print Page | Close Window

8070 FWA

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=206839
Printed Date: 18 Jul 2025 at 1:45am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: 8070 FWA

Posted By: Big Orange
Subject: 8070 FWA
Date Posted: 22 May 2025 at 9:25pm

What is my problem? My 8070 front diff. lub. oil is milky colored. I know it has water in it, because, if I pull the drainplug, after it sets a long time, I get water. I have changed the lube oil a number of times. 80w90 85w140 90synthetic, What is going on?

Replies:

Posted By: Codger
Date Posted: 23 May 2025 at 3:54am

There will be a vent that should be open to atmosphere that could be broken allowing water entrance, of where you park the tractor is very humid. As the differential cools after usage, it will draw moisture from the moisture laden surrounding air.

Of course all of this precludes submerging the axle into a creek, pond, body of water etc.

-------------
That's All Folks!

Posted By: DrAllis
Date Posted: 23 May 2025 at 7:17am

The FWA differential compartment breather is a hex plug directly on top of one of the axle tubes. It has a simple O-ring wrapped around a machined groove. Maybe this O-ring is missing ?? The design allows a small pressure build up in the compartment and then the O-ring expands and burps the pressure. When the axle temps cool down it creates a vacuum inside that I always assumed the drive axle seals allowed some air to come back inside to lessen the vacuum. Anyway, check that breather on top and see if the O-ring is missing.