1992 Rear axle grease change.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 244
Likes: 26
From: Carmel, Indiana
1992 Rear axle grease change.
Planning on changing the rear axle fluid in my 92, check vids on YT but would like someone on CF to confirm the correct grease to use and whether additive can be included with the grease or sperate?
Thanks
Thanks
Advanced
Joined: Oct 2023
Posts: 62
Likes: 64
From: Triad Area, NC
I did that this weekend. I used Valvoline 75w90 GL5 with about 8 ounces of ACDelco10-4003 Limited Slip Axle Lubricant Additive. The differential fluid plug took a 3/8 Allan bit (9mm would work too). Make sure you have a good hand pump to suck out old fluid and pump in new fluid.
Keep in mind that oils and fluids are a religion; everyone thinks that only their choice is correct. You do you.
Keep in mind that oils and fluids are a religion; everyone thinks that only their choice is correct. You do you.
Last edited by AffableCurmudgeon; Oct 10, 2023 at 09:33 AM.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 244
Likes: 26
From: Carmel, Indiana
AC. I was just searching for the oil and have a question did you use synthetic or conventional and how much did it take, (saving me the time to look it up), also, does it make any difference how the additive goes in, I'm assuming I can mix it all together and pump it in? (I know I'm probably over thinking it)
Thanks again
Thanks again
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
Don't over think it. After you pump all the old fluid out you first pump in the GM friction modifier and then just fill it with the gear oil until it runs out the the plug hole. No need to pre mix. As noted everyone has their own favorite. I use Amsoil products and been very happy with them.
Advanced
Joined: Oct 2023
Posts: 62
Likes: 64
From: Triad Area, NC
AC. I was just searching for the oil and have a question did you use synthetic or conventional and how much did it take, (saving me the time to look it up), also, does it make any difference how the additive goes in, I'm assuming I can mix it all together and pump it in? (I know I'm probably over thinking it)
Thanks again
Thanks again
As for what I used, I used conventional. For quantity, I used bit over a quart (I buy in gallon jugs for use with my other cars as well so hard to tell exactly how much more than a quart; definitely less than quart and a half). I have been using the same gear oil for decades on other cars and motorcycles and I like it. Like I said, oil brand is more of a personal preference than anything else. So long as you meet the GL5 specs, you are good.
Racer
Joined: Mar 2020
Posts: 387
Likes: 148
From: Langton, Ontario, Canada
2025 C4 of the Year Finalist - Unmodified
I just changed my rear differential fluid with Lucas 75W90 Synthetic oil. On the bottle, it said it had "friction modifiers" in it, so I didn't put any additives in it. I have been surprised since then, because the limited slip function actually works, and works well! I never noticed it before, but now, going around a corner, you can hear the tires chirping. I'm very impressed!
Safety Car
Joined: Mar 2017
Posts: 4,187
Likes: 1,307
From: LeClaire Iowa
I just changed my rear differential fluid with Lucas 75W90 Synthetic oil. On the bottle, it said it had "friction modifiers" in it, so I didn't put any additives in it. I have been surprised since then, because the limited slip function actually works, and works well! I never noticed it before, but now, going around a corner, you can hear the tires chirping. I'm very impressed!
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Thread Starter
Instructor
Joined: Jun 2011
Posts: 244
Likes: 26
From: Carmel, Indiana
I know I was not going to over think this but so far I've seen folks using 4oz of LSA , 8oz of LSA and my FSM say's 12 oz's of LSA, should I just go with the FSM or just take my pick?
Picky rappini.
Picky rappini.
Safety Car
Joined: Mar 2017
Posts: 4,187
Likes: 1,307
From: LeClaire Iowa
When it makes real funny noises turning tight (and it will) then go ahead and suck some out and add the additive. Dan
Race Director
Joined: Aug 2000
Posts: 11,470
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side note - if you need a transfer pump, harbor freight has one for $5-$7 (depending on their current, on-going sale). at that price, pretty much a throw-away item when done. as for the brand of gear oil, most premium brands have LSD additive, however, i do add 4oz of GM additive duting my 85's differential service. FWIW, i'm at the 170K mile mark w/o issue.
Safety Car
Joined: Mar 2017
Posts: 4,187
Likes: 1,307
From: LeClaire Iowa
Not trying to win I am just happy you won't be making the same mistake I did when I trusted the LSA in some brands. I had to add the GM additive later. Something about our rears that is different and we need more. Experts can probably explain why. After finishing it is important to go to a parking lot and do 10-15 tight figure eights to distribute the LSA. Dan edit: I have never seen 3 bottles of the additive. If that was the case the bottle would be 12 oz instead of 4 oz.
