Changing rear diff oil no fill hole
Thread Starter
Junior Member
Joined: Aug 2023
Posts: 79
Likes: 4
Changing rear diff oil no fill hole
So I decided to change the rear diff oil bought a nice new chrome cover ect.Now ive done this before which is straight forward. It's 9 bolt I borg Wagner.The cover has a drain plug so I assume I fill there as well as I don't see a fill hole on the pumpkin.
Last edited by Chaddyboy; Oct 21, 2023 at 12:58 PM.
Supreme Member
Joined: Sep 1999
Posts: 3,022
Likes: 820
From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Changing rear diff oil no fill hole
The fill hole is on the passenger side of the differential. ALL differentials on these cars have it...
Thread Starter
Junior Member
Joined: Aug 2023
Posts: 79
Likes: 4
Supreme Member
Joined: Sep 1999
Posts: 3,022
Likes: 820
From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Changing rear diff oil no fill hole
Yeah, you gotta use the stock cover on the 9-bolt (or one with a fill hole)...
Last edited by T.L.; Oct 21, 2023 at 01:19 PM.
Supreme Member
Joined: Jan 2004
Posts: 2,322
Likes: 100
From: So. Ohio
Car: 88 Camaro
Engine: L98 350
Transmission: 700r4
Re: Changing rear diff oil no fill hole
Does that new cover actually fit the 9 bolt rear? Hot setup would be a finned aluminum cover with a fill and drain plug.
Joined: Sep 2005
Posts: 27,935
Likes: 2,454
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Changing rear diff oil no fill hole
As long as the fill hole in the cover is at the same height as the one in the stock cover, it'll be fine. Hopefully it has something intelligent instead of the stuuuupid stock 9-bolt rubber plug thing. A pipe plug is SO much better.
Obviously you want to get as much fluid into it as the stock one allowed. But you don't want TOO much; if the level is above the bottom of the axle tubes, then they'll be full of fluid ALL the time, and the seals will leeeeek it out WITHOUT MERCY. You don't want to fill it above that level.
Obviously you want to get as much fluid into it as the stock one allowed. But you don't want TOO much; if the level is above the bottom of the axle tubes, then they'll be full of fluid ALL the time, and the seals will leeeeek it out WITHOUT MERCY. You don't want to fill it above that level.
Thread Starter
Junior Member
Joined: Aug 2023
Posts: 79
Likes: 4
Re: Changing rear diff oil no fill hole
Trending Topics
Thread Starter
Junior Member
Joined: Aug 2023
Posts: 79
Likes: 4
Re: Changing rear diff oil no fill hole
As long as the fill hole in the cover is at the same height as the one in the stock cover, it'll be fine. Hopefully it has something intelligent instead of the stuuuupid stock 9-bolt rubber plug thing. A pipe plug is SO much better.
Obviously you want to get as much fluid into it as the stock one allowed. But you don't want TOO much; if the level is above the bottom of the axle tubes, then they'll be full of fluid ALL the time, and the seals will leeeeek it out WITHOUT MERCY. You don't want to fill it above that level.
Obviously you want to get as much fluid into it as the stock one allowed. But you don't want TOO much; if the level is above the bottom of the axle tubes, then they'll be full of fluid ALL the time, and the seals will leeeeek it out WITHOUT MERCY. You don't want to fill it above that level.
Member
Joined: Aug 2004
Posts: 228
Likes: 12
From: Ottawa
Car: 86 IROC
Engine: Twin turbo L31 HSR
Transmission: 4L80E in progress
Axle/Gears: 9 bolt 4.11
Re: Changing rear diff oil no fill hole
Then this might be your only choice other than the stock one: https://www.taperformance.com/prodde...prod=TA%5F1802
Joined: Sep 2005
Posts: 27,935
Likes: 2,454
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Changing rear diff oil no fill hole
I don't think
I screwed up thinking
IROCs from 87 to 89, and maybe a few 90s, often came with 9-bolts. Especially the TPI cars. The carb and TBI ones more usually had 10-bolts. Still, not hard to stick your head up under there and check.
Always LOOK AT your car before you buy parts for it. I don't really want to be a jerk or anything (it just comes naturally to me), but it's hard to be sympathetic toward you when you could have just counted the bolts.
Thread Starter
Junior Member
Joined: Aug 2023
Posts: 79
Likes: 4
Re: Changing rear diff oil no fill hole
I do that all the time. Both of them. Doesn't seem to matter thinking, or not, about what; just, thinking or not, instead of looking and getting the facts, is the problem.
IROCs from 87 to 89, and maybe a few 90s, often came with 9-bolts. Especially the TPI cars. The carb and TBI ones more usually had 10-bolts. Still, not hard to stick your head up under there and check.
Always LOOK AT your car before you buy parts for it. I don't really want to be a jerk or anything (it just comes naturally to me), but it's hard to be sympathetic toward you when you could have just counted the bolts.
IROCs from 87 to 89, and maybe a few 90s, often came with 9-bolts. Especially the TPI cars. The carb and TBI ones more usually had 10-bolts. Still, not hard to stick your head up under there and check.
Always LOOK AT your car before you buy parts for it. I don't really want to be a jerk or anything (it just comes naturally to me), but it's hard to be sympathetic toward you when you could have just counted the bolts.
Thread
Thread Starter
Forum
Replies
Last Post
fastlane350
Transmissions and Drivetrain
1
Mar 16, 2011 04:57 PM
joshwilson3
Transmissions and Drivetrain
13
Jun 27, 2010 06:13 PM
foney_email
Transmissions and Drivetrain
6
Sep 27, 2002 08:16 AM