Lucas gear oil and posi additive?? - Chevelle Tech
Transmission & Driveline Transmissions and Differentials

 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 5 (permalink) Old Apr 2nd, 09, 9:16 PM Thread Starter
Tech Team
Tom
 
Join Date: Jul 2007
Location: Warrensburg, NY
Posts: 108
Lucas gear oil and posi additive??

Just got back from the auto store. Bought 2 bottles of Lucas Gear Oil 80-90 for my rear differential 70 Chevelle SS with 3:31 posi). It says on the bottle that the the posi additive is not necessary. Looking for thoughts on this. The guy behind the counter at Advance said it won't hurt anything to add it. I want to add it anyway. Just wanted to hear from people who may have run into this situation before. Thanks in advance. Tom.
slvrchvllss is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old Apr 2nd, 09, 10:27 PM
Gold Founding Member
 
Join Date: Nov 2005
Location: Camaro-n-Chevelle Heaven
Posts: 4,007
Re: Lucas gear oil and posi additive??

I used the Kendall 80-90 Gear Oil with the Posi Additive. I still went to the dealership and purchased the Posi Additive. It will not hurt anything.

Tory
ACES Member #1890
Team Chevelle Gold #288

1955 Chevrolet Bel Air Unrestored 15,000 Mile Survivor
1955 Chevrolet Nomad
1964 Malibu SS Unrestored 36,000 Mile Survivor
1964 Malibu SS
1966 Chevelle SS 396 Unrestored 76,000 Mile Survivor
1968 Camaro
1968 Malibu L-79, 1 of 4082 ~ SOLD
1984 Hurst Olds w/ Factory Sunroof, 1 of 99 ~ SOLD
1985 442 White / Grey w/ Factory Sunroof ~ SOLD
Lionel-n-Chevelles is offline  
post #3 of 5 (permalink) Old Apr 2nd, 09, 10:27 PM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: Lucas gear oil and posi additive??

i just dumped 1.75 pints into the 7.5 in my dd ta.
posi still works, but ive only got about 300 miles on since then. it said it meets the gm number.


aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
post #4 of 5 (permalink) Old Apr 5th, 09, 9:14 AM Thread Starter
Tech Team
Tom
 
Join Date: Jul 2007
Location: Warrensburg, NY
Posts: 108
Re: Lucas gear oil and posi additive??

Can you even find a name brand gear oil without the additive in it? I just don't want "too much" additive in the rear end if there is such a thing. I would like to use the GM additive since I already have it, and I am willing to get different gear oil if there is even a small concern. Thanks again. Tom.
slvrchvllss is offline  
post #5 of 5 (permalink) Old Apr 5th, 09, 2:09 PM
Senior Tech Team
 
Join Date: Oct 1999
Location: DuPont, Washington
Posts: 1,624
Wink Re: Lucas gear oil and posi additive??

Quote:
Originally Posted by slvrchvllss View Post
Can you even find a name brand gear oil without the additive in it? I just don't want "too much" additive in the rear end if there is such a thing. I would like to use the GM additive since I already have it, and I am willing to get different gear oil if there is even a small concern. Thanks again. Tom.
You can find gear lube "without the additive". It is API GL-4. More likely to find it in a hardware or farm supply store. Supposedly the "additive" makes it more likely that the oil will attack copper/zinc alloys brass bronze etc. like maybe synchromesh components in a transmission. I wouldn't for instance use GL-5 in my roto-tiller because it has a bronze gear in the transmission.

In any case, some good quality API GL-5 gear lube will be fine for limited slip differentials including "Positraction". See here for some words and specs and applications.

If it was me, I'd take the Lucas and additives back, and check some Pennzoil or Quaker State or other brand name GL-5 spec and see if it covers limited-slip. If it does I'd run it, and use some additive only if I had any grabbing or chattering like I did with my '65 after 90,000 miles. I replaced the stock fill with Sta-Lube GL-5 90 wt., and its been OK since, w/o any additives.

Just my $0.02

Last edited by JJ'65; Apr 5th, 09 at 8:11 PM.
JJ'65 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome