Changing rear Diff Fluid

Reply Subscribe

Thread Tools

Search this Thread

Sep 3, 2016 | 11:32 AM

hharris8

Thread Starter

Elder User

Joined: Dec 2015

Posts: 816

Likes: 0

Changing rear Diff Fluid

I have a 86 Bronco and need to change he rear diff fluid. I opened the plug today and it was nearly a half a gallon low (been sitting for about 8 years since driving much). I filled it up for now, but there is apparently a leak and I want to change the gasket soon and get out any metal shavings there may be in there. I was not even able to siphon the old oil out because the siphon hose would not go in to the bottom because something was blocking it.

My questions is, what size diff does a 86 Bronco have?

Also, on my other truck the diff had a pumpkin cover on the rear, this truck only has the cover the drive shaft is attached to. How do I remove the cover to be able to change the gasket?

Thanks in advance!

Sep 3, 2016 | 01:46 PM

ManfredVonRichtofen

Postmaster

Joined: Nov 2009

Posts: 3,189

Likes: 0

From: SE Georgia

Quote:

Originally Posted by hharris8

that is a ford 9 inch you have. newer broncos got the 8.8 rear.

Disconnect the driveshaft. unbolt the pumpkin (diff cover). the whole gear set will come out. replace gasket. install back on.

Sep 3, 2016 | 08:58 PM

hharris8

Thread Starter

Elder User

Joined: Dec 2015

Posts: 816

Likes: 0

Thanks, I will try that ASAP and let you know how it goes. Does the driveshaft just disconnect very simply or will it take some sort of special know how?

Sep 3, 2016 | 10:03 PM

ManfredVonRichtofen

Postmaster

Joined: Nov 2009

Posts: 3,189

Likes: 0

From: SE Georgia

Quote:

Originally Posted by hharris8

Thanks, I will try that ASAP and let you know how it goes. Does the driveshaft just disconnect very simply or will it take some sort of special know how?

Easy...just some wrenches. Also have a stop behind the tires so the truck doesn't roll back on you. Keep the transmission in gear so the driveshaft doesn't rotate.

Sep 4, 2016 | 06:30 AM

gatorfor88

Postmaster

Joined: Jan 2013

Posts: 3,512

Likes: 3

From: Panama City

You are going to have to slide rear axles out enough to get the center section out.

Sep 4, 2016 | 08:34 AM

hharris8

Thread Starter

Elder User

Joined: Dec 2015

Posts: 816

Likes: 0

Quote:

Originally Posted by gatorfor88

You are going to have to slide rear axles out enough to get the center section out.

Please explain. That sounds intimidating.

Sep 4, 2016 | 09:29 AM

gatorfor88

Postmaster

Joined: Jan 2013

Posts: 3,512

Likes: 3

From: Panama City

you have to remove rear tires, remove brake drums. There is a hole in the axle flange you stick a socket through to remove 4 bolts that hold axle retainer on. Slide axles out about a foot. Then you can remove the center section. Just be careful because it is HEAVY. Not really that difficult a job if you have any mechanical inclination. Also you want to use some rtv sealant on the "chunk" whether you use a gasket or not.