Gear oil viscosity question.
Thread Starter
Senior Member
iTrader: (1)
Joined: Feb 2007
Posts: 730
Likes: 0
From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Gear oil viscosity question.
I just finished putting my rear differential together after replacing the pinion yoke seal. I had purchased two quarts of lucas gear oil and also the LSD additive. Unfortunately, the guy at advance auto, where I purchased the lucas oil had accidentally pulled one quart of the 80W-90 gear oil, and the second quart was 85W-140. Without paying much attention I added the 85W-140 oil, thinking that I had gotten two quarts of 80W-90. By the time I realised the mistake, I had already emptied the whole quart of the heavier oil on top of the 4 ounces of limited slip additive. I filled up the rest of my differential with the 80W-90 and now I have 1 quart of 85w-140 and half of a quart of the 85w-140.
What are the negative consequences that can result from this? The car seems to go down the road fine without any strange noises or vibrations even after taking it to 80 mph. Other than increased drag on the rear axle as a result of the heavier oil, is there any damage that can occur as a result of this?
I plan on changing it back to the correct viscocity, but it may take me a couple of weeks before I get a chance to do that.
What are the negative consequences that can result from this? The car seems to go down the road fine without any strange noises or vibrations even after taking it to 80 mph. Other than increased drag on the rear axle as a result of the heavier oil, is there any damage that can occur as a result of this?
I plan on changing it back to the correct viscocity, but it may take me a couple of weeks before I get a chance to do that.
Joined: Jun 2000
Posts: 5,364
Likes: 51
From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: Gear oil viscosity question.
Leave as is, the thicker visco oil will not thin out as much as the thinner one. Both will be fine.
Supreme Member
iTrader: (17)
Joined: Nov 2005
Posts: 1,104
Likes: 2
From: Leicester,Massachusetts
Car: 1983 CHEVROLET CAMARO Z28
Engine: Forged 355 with a GT45 turbo
Transmission: TKO 600
Axle/Gears: built 4th gen rear with 3.27s
Thread Starter
Senior Member
iTrader: (1)
Joined: Feb 2007
Posts: 730
Likes: 0
From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Re: Gear oil viscosity question.
Yes, I got the bolt out. It seems that it was the clamping force holding it in place. Nothing I did, including heating the carrier near the bold, worked. I ended up drilling a pilot hole through the bolt, removing the head and the differential cover, and then the bolt came out with a small extractor pretty much by hand.
Thanks for your help.
Thanks for your help.
Thread Starter
Senior Member
iTrader: (1)
Joined: Feb 2007
Posts: 730
Likes: 0
From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Supreme Member
Joined: Sep 2008
Posts: 3,777
Likes: 0
Re: Gear oil viscosity question.
It's going to be fine. The 80W140 means that the viscosity is 80 when it's cold and 140 when it gets warm. Most new trucks come with 80W140 in them from the factory now. They use synthetic oil, but yours will be fine with what you have. I'm running Amsoil 75W140 in the 7.5 in my S truck because of the locker. Haven't had any problems with it in over 130,000 miles.
Thread
Thread Starter
Forum
Replies
Last Post
ambainb
Camaros for Sale
11
Apr 25, 2016 09:21 PM
gixxer92
Engine/Drivetrain/Suspension Parts for Sale
5
Sep 1, 2015 04:32 PM
downsouthboy
Tech / General Engine
4
Aug 29, 2015 11:29 AM
Navy8125
Engine/Drivetrain/Suspension Parts for Sale
4
Aug 21, 2015 09:32 AM
