C5 6 Speed transmission fluid
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 32
Likes: 5
From: North Aurora IL
C5 6 Speed transmission fluid
I recently purchased a 1997 C5 6 speed with 41,000 miles on it. The shifting was rather sticky and substandard. I changed the trans fluid, it looked terrible. I used Valvoline synthetic ATF as the replacement trans fluid. The shifting improved dramatically, Then changed it again after 300 miles. The shifting improved but it's nowhere close to the " Hot Knife Through Butter"
Not satisfied with the results of the fluid change but happy my reverse lights worked now. Reading up on this "Shitty Shifting" issue it's recommended to use AC Delco Synchromesh Transmission Fluid 32oz Quart 88900333. This ATF is allegedly hard to find, And it is.... I found pricing from $33 per quart to $18 per quart on the net. I called my local NAPA store in Naperville IL and yeah we have it. Ok how much... $8.80 per quart. I told him to put 4 quarts aside and was there in minutes. So to bottom line this information, USE THE AC DELCO SYNCHROMESH 88900333 That's your GENIE IN A BOTTLE.
While pumping the Synchromesh into the trans you can see shiny suspended particles in the dark gold fluid. No other fluid has this additive.
I can certainly tell the difference with the correct trans fluid. Easer shifting cold or hot, less gear noise... Its like a a refined transmission.
Not satisfied with the results of the fluid change but happy my reverse lights worked now. Reading up on this "Shitty Shifting" issue it's recommended to use AC Delco Synchromesh Transmission Fluid 32oz Quart 88900333. This ATF is allegedly hard to find, And it is.... I found pricing from $33 per quart to $18 per quart on the net. I called my local NAPA store in Naperville IL and yeah we have it. Ok how much... $8.80 per quart. I told him to put 4 quarts aside and was there in minutes. So to bottom line this information, USE THE AC DELCO SYNCHROMESH 88900333 That's your GENIE IN A BOTTLE.
While pumping the Synchromesh into the trans you can see shiny suspended particles in the dark gold fluid. No other fluid has this additive.
I can certainly tell the difference with the correct trans fluid. Easer shifting cold or hot, less gear noise... Its like a a refined transmission.
Last edited by number44; Mar 6, 2017 at 09:58 AM. Reason: add on
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 32
Likes: 5
From: North Aurora IL
Team Owner
Joined: May 2001
Posts: 87,375
Likes: 1,593
From: Western NY
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 32
Likes: 5
From: North Aurora IL
DO NOT run the synthetic ATF in the pre-1997 T-56 units.
"I spoke with the T-56 expert at Tremec. He said that the Mobil 1 Synthetic ATF is an excellent choice for the T-56, PROVIDED that the T-56 is a 1997 model or newer.
DO NOT run the synthetic ATF in the pre-1997 T-56 units. It will destroy the paper on the blocker rings. And do not run it in a manual trans with brass blocker rings either, because it will ruin those also.
Tremec changed the blocker rings to the carbon fiber type for the 1997 model year and synthetic ATF will not degrade these.
DO NOT run the synthetic ATF in the pre-1997 T-56 units. It will destroy the paper on the blocker rings. And do not run it in a manual trans with brass blocker rings either, because it will ruin those also.
Tremec changed the blocker rings to the carbon fiber type for the 1997 model year and synthetic ATF will not degrade these.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 32
Likes: 5
From: North Aurora IL
"I spoke with the T-56 expert at Tremec. He said that the Mobil 1 Synthetic ATF is an excellent choice for the T-56, PROVIDED that the T-56 is a 1997 model or newer.
DO NOT run the synthetic ATF in the pre-1997 T-56 units. It will destroy the paper on the blocker rings. And do not run it in a manual trans with brass blocker rings either, because it will ruin those also.
Tremec changed the blocker rings to the carbon fiber type for the 1997 model year and synthetic ATF will not degrade these.
I asked about the GM SynchroMesh and he said it was good, but not quite as good as the Mobil 1 Synthetic ATF. The SynchroMesh fluid comes in the Tremec 3550.
He said you should have no problems running the Mobil 1 Synthetic ATF in the T-56.
Notice how I keep saying "Mobil 1 Synthetic ATF". He said stay away from the other aftermarket racing type synthetics, as they have extra additives that can degrade components.
DO NOT run the synthetic ATF in the pre-1997 T-56 units. It will destroy the paper on the blocker rings. And do not run it in a manual trans with brass blocker rings either, because it will ruin those also.
Tremec changed the blocker rings to the carbon fiber type for the 1997 model year and synthetic ATF will not degrade these.
I asked about the GM SynchroMesh and he said it was good, but not quite as good as the Mobil 1 Synthetic ATF. The SynchroMesh fluid comes in the Tremec 3550.
He said you should have no problems running the Mobil 1 Synthetic ATF in the T-56.
Notice how I keep saying "Mobil 1 Synthetic ATF". He said stay away from the other aftermarket racing type synthetics, as they have extra additives that can degrade components.