C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Diff Oil Temp Sensor.

Old May 9, 2023 | 01:16 AM
  #1  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default Diff Oil Temp Sensor.

I am looking to add a diff oil temp sensor using the Diff Drain / Fill Plug. Anyone know the thread specs for the filler plug.

As for reasons, car is mainly used for track days and adding a diff oil cooler to the car.

I believe its a 14 TPI
Reply
Old May 9, 2023 | 02:32 AM
  #2  
76strokervette's Avatar
76strokervette
Burning Brakes
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
Default

3/4 - 14 npt is the thread size for the fill plug.
Reply
Old May 9, 2023 | 08:14 AM
  #3  
GTR1999's Avatar
GTR1999
Tech Contributor
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 1999
Posts: 15,175
Likes: 3,987
From: Connecticut, USA
Default

REM is good for cutting down on friction and heat generation.
Reply
Old May 9, 2023 | 09:47 PM
  #4  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by GTR1999
REM is good for cutting down on friction and heat generation.
Understand that will help, but after enough miles will this not happen anyways. My original diff now has 220k km and only items replaced are the side yokes.

as for my new diff I am expecting it to run hot until the gears start to wear a bit, or will good friction modifiers prevent this from happening at all.

So step 1 I want to measure the temps to see if I should add a cooler for track days. Normally where I drive a hot day is 25c (77) but we are now experencing 30-33c (86-92) spring days.
Reply
Old May 9, 2023 | 09:48 PM
  #5  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by 76strokervette
3/4 - 14 npt is the thread size for the fill plug.
Thanks I will start to look for a reducer to install a temp sensor. Then measure a starting point.
Reply
Old May 9, 2023 | 10:31 PM
  #6  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

What is your gear ratio.
Reply
Old May 9, 2023 | 11:16 PM
  #7  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by gkull
What is your gear ratio.
I have 2 diff's
1. 3.08 factory original
2. 3.36 new diff

This was selected based on Engine RPM at end of straights at my local track. 3.55 hits red line before end of straight, 3.73 changed from 2&3rd gear to 3&4th and low RPM at end of straight.
Reply
Old May 10, 2023 | 12:11 AM
  #8  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

Originally Posted by cagotzmann
I have 2 diff's
1. 3.08 factory original
2. 3.36 new diff

This was selected based on Engine RPM at end of straights at my local track. 3.55 hits red line before end of straight, 3.73 changed from 2&3rd gear to 3&4th and low RPM at end of straight.
You do understand that lower numerical number differentials run cooler? How much power you are putting to it makes a big difference. My advice is when you pull into the pits after a session of lots of hot laps, get out the temp gun to get the hottest point on the case. I found that my 4.11 ran cooler with 75W-140 syn power. But generally I never got much over 245 degrees. I debated on a manual tranny and diff cooler like this vette I used to work on.

I always wanted to weld up the centered jacking point on my Vette.
Gary R. also pointed out that this is NOT plumed correctly. It should spray from the side of the cover aimed at the ring gear. This is Vic Edelbrocks old vette back when he was still racing and it does have a nice pusher fan setup through the radiator.


Last edited by gkull; May 10, 2023 at 10:18 AM.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old May 10, 2023 | 05:52 AM
  #9  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

I tried to find max temp for Valvoline full synthetic 75W-140 and I came up with this. They conducted tests on oil/component durability. They found components should not be operated at consistent temperatures above 250F. Intermittent operations to 300F do not harm the components or oils (synthetics).

Kind of like the old Mobil One commercial heating the synthetic in a frying pan to something like 280F before it started to change color and smoke.

My 245 was on a 105 degree day last spring race in Vegas before the summer heat shut down on the long road course. @30 minute sprint race sessions. I had a cooled air helmet and was thinking that I needed to invest in a full cool suite before getting a diff cooler! The track temp was almost 140 and probably over 120 inside my hot vette waring a fire suit, gloves and boots.
Reply
Old May 10, 2023 | 06:02 AM
  #10  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

This drain plug is the best mod you can do and the second best is polishing out the heavy duty rear diff cover. Something Gary told me to do. The HD diff covers are so robust compared to a OEM.



Just getting started making my inside cover look like a mirror.

Reply
Old May 10, 2023 | 10:22 PM
  #11  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by gkull
I always wanted to weld up the centered jacking point on my Vette.
Gary R. also pointed out that this is NOT plumed correctly. It should spray from the side of the cover aimed at the ring gear. This is Vic Edelbrocks old vette back when he was still racing and it does have a nice pusher fan setup through the radiator.

Drain added same location as yours.
Fill entry here. Which looks like entry is direct at the gears.


They also added the wire support since I have had bolts come loose and drop into the diff. ( not sure if this was a good idea ) but I did read about others having similar problems.


Reply
Old May 10, 2023 | 10:40 PM
  #12  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

I took apart a customer rear end and half the bolts were loose. I've always used red Loctite and ARP bolts and never had a problem.
Reply
Old May 10, 2023 | 10:48 PM
  #13  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by gkull
I took apart a customer rear end and half the bolts were loose. I've always used red Loctite and ARP bolts and never had a problem.
Is the wire over kill ? or another problem waiting to happen. Diff builder added this.
Reply
Old May 10, 2023 | 10:53 PM
  #14  
cagotzmann's Avatar
cagotzmann
Thread Starter
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,116
Likes: 598
Default

Originally Posted by gkull
This drain plug is the best mod you can do and the second best is polishing out the heavy duty rear diff cover. Something Gary told me to do. The HD diff covers are so robust compared to a OEM.



Just getting started making my inside cover look like a mirror.

I would think "Rough, dark, and matte surfaces demonstrate the highest absorption / cooling potential" more surface area to absorb and radiate ????
Reply
Old May 11, 2023 | 09:28 AM
  #15  
Bikespace's Avatar
Bikespace
Race Director
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Mar 2017
Posts: 11,949
Likes: 4,507
From: Virginia
Default

Originally Posted by gkull
This drain plug is the best mod you can do and the second best is polishing out the heavy duty rear diff cover. Something Gary told me to do. The HD diff covers are so robust compared to a OEM.

Just getting started making my inside cover look like a mirror.
Originally Posted by cagotzmann
I would think "Rough, dark, and matte surfaces demonstrate the highest absorption / cooling potential" more surface area to absorb and radiate ????
I was wondering about that too. @gkull, can you explain the reasoning behind this, or point to an online reference? Does it reduce frothing of the oil or something?

You have an external oil cooler, and even if you didn't, I can't imagine it helps with that in any measurable way. Just bolting on some CPU cooling fins to the outside of the cover would seem to have a much larger effect.

Last edited by Bikespace; May 11, 2023 at 06:29 PM.
Reply
Old May 12, 2023 | 12:00 AM
  #16  
gkull's Avatar
gkull
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Default

Originally Posted by Bikespace
I was wondering about that too. @gkull, can you explain the reasoning behind this, or point to an online reference? Does it reduce frothing of the oil or something?

You have an external oil cooler, and even if you didn't, I can't imagine it helps with that in any measurable way. Just bolting on some CPU cooling fins to the outside of the cover would seem to have a much larger effect.
Oil drain back faster than a rough surface. Same idea as polished cam valley on a v-8 and like pistons inside and rods coated with oil repellant surfaces. My Motown block has all kinds of ideas to prevent windage loss including the blocked off cam valley and vent tubes. Steel sleeved lifter bores. lots of little things add up!

I had the Wiseco custom pistons cut for up to 2.18 intake valves and .800 lift


Last edited by gkull; May 12, 2023 at 12:08 AM.
Reply

Get notified of new replies

To Diff Oil Temp Sensor.



Thread Tools
Search this Thread

All times are GMT -4. The time now is 11:10 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE