ZF5 fluid question
Thread Starter
|
Tuned
Joined: Nov 2019
Posts: 421
Likes: 67
ZF5 fluid question
hey guys, new member here. So I’ve got a 1994 f250 with the ZF5, and the 3rd gear synchro is a little worn. When it’s warm outside it shifts ok but when it’s cold out it won’t even go into 3rd. once the tranny warms up it will shift. I’ve heard good things about Redline MTL and how it can make worn synchros shift better, but I’ve also heard it makes cold weather shifting harder, is this true? Should I put Redline in my tranny or good atf or what? it’s got atf in it now but I don’t know what kind
Thread Starter
|
Tuned
Joined: Nov 2019
Posts: 421
Likes: 67
were you having problems shifting before? did it help? I haven’t heard of that solution before...
Fleet Owner
Joined: Jan 2004
Posts: 26,007
Likes: 575
From: Brentwood,CA
Mixing the two gets you just slightly thicker than the mercon ATF. Keep in mind gear oils and ATF are rated differently and a oil like MTL is actually very similar to mercon and is actually around 6.1 CST viscosity. It also satisfies the following from the Redline tech files.
Red Line MTL is classified as a 75W/80W gear lubricant satisfying the API Service requirements of GL-3 and GL-4. MTL also satisfies motor oil viscosities SAE 5W/10W/30, and the viscosity requirements for ATFs. MT-90 is a 75W90 GL-4 and also satisfies motor oil viscosities SAE 10w40, 15w40.
There is lots of information about mixing the lubes online and from Redline directly. Look over at BITOG.
Tuned
Joined: Jun 2015
Posts: 354
Likes: 8
From: Winchester, KY,USA
Earlier this year I drained my M5OD gearbox and used Synchromesh manual transmission fluid instead. My gearbox shifts so much better and I can honestly say I wished I had done it sooner and that I won't be going back to ATF.
Trending Topics
Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
I "wasted" my money on the redline fluid. Didn't do anything. But a rebuild fixed the sycnronizer problem
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
Selder
1987 - 1996 F150 & Larger F-Series Trucks
11
Dec 8, 2008 07:09 PM
1990Fordf150v8
Clutch, Transmission, Differential, Axle & Transfer Case
2
Oct 22, 2003 11:28 AM