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ATF in FM146?


RescueRanger

Well-Known Member
Solid Axle Swap
Joined
Nov 14, 2009
Messages
53
City
NM
Vehicle Year
2000, 89
Transmission
Automatic
hey guys,

I was going to change fluid in transmission today it is a FM146 in a 89 ranger with 2.9 before draining I looked on here at tech library to see what fluid to buy and the FM146 calls for 80w-90 and the 1350m calls for the mercon II atf anyways I pulled the plug on transmission and it was atf, so did the previous owner goof or did I read the wrong info or is it possible the FM146 is out of a newer ranger and it possibly calls for atf, thanks for any help I want to make sure and put right fluid back in it. oh and I called two transmission shops in town and both said they were pretty sure it was suppose to be atf.
 
All FM146s take gear oil, regardless of year. Only the M5OD takes ATF.
 
okay thanks I hope that there isnt anything wrong with this transmission I havent ran it yet but when I drained it the fluid looked nice and clean so hopefully the previous owner didnt run it much after changing it. If he had ran it a lot what would it do burn up bearings or something?
 
one more question I read on here somewhere that your suppose to use 80w-90 GL4 not GL5 is this true and would it hurt to use the GL5? I ask cause I have a 5 gallon bucket with regular ole 80/90w but it has a hand pump on it and it is super easy to fill diffs and what not. thanks for any replies.
 
There was a TSB put out some years ago saying that ATF CAN be used in the FM146. It is still generally considered a bad idea by most guys who know anything about them.
 
oooops. I have been running atf in mine for about 20K miles.... but I am not even sure which trans I have - according to some posts anything after 8/89 is m50d - mine was built in on 8/89.
 
I read on here somewhere that your suppose to use 80w-90 GL4 not GL5 is this true

i worked 5 years in the "quick lube" business. i haven't even seen a gl-5 produced in the last decade that didn't also meet the specs for gl-4, and even gl-3 for that matter
 
If I were running that transmission, I'd probably be running Redline MT-85 or MT-90 or something equivalent in it, depending on temperature. I thought if you run regular GL-5 80w90 gear oil it tends to eat the synchros.
 
I thought if you run regular GL-5 80w90 gear oil it tends to eat the synchros.
here:
API classification subdivides all transmission oils into 6 classes:

API GL-1, oils for light conditions. They consist of base oils without additives. Sometimes they contain small amounts of antioxidizing additives, corrosion inhibitors, depresants and antifoam additives. API GL-1 oils are designed for spiral-bevel, worm gears and manual transmissions without synchronizers in trucks and farming machines.
API GL-2, oils for moderate conditions. They contain antiwear additives and are designed for worm gears. Recommended for proper lubrication of tractor and farming machine transmissions.
API GL-3, oils for moderate conditions. Contain up to 2.7% antiwear additives. Designed for lubricating bevel and other gears of truck transmissions. Not recommended for hypoid gears.
API GL-4, oils for various conditions - light to heavy. They contain up to 4.0% effective antiscuffing additives. Designed for bevel and hypoid gears which have small displacement of axes, the gearboxes of trucks, and axle units. Recommended for non-synchronized gearboxes of US trucks, tractors and buses and for main and other gears of all vehicles. These oils are basic for synchronized gearboxes, especially in Europe.
API GL-5, oils for severe conditions. They contain up to 6.5% effective antiscuffing additives. The general application of oils in this class are for hypoid gears having significant displacement of axes. They are recommended as universal oils to all other units of mechanical transmission . Oils in this class, which have special approval of vehicle manufacturers, can be used in synchronized manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS.
API GL-6, oils for very heavy conditions (high speeds of sliding and significant shock loadings). They contain up to 10% high performance antiscuffing additives. They are designed for hypoid gears with significant displacement of axes. Class API GL-6 is not applied any more as it is considered that class API GL-5 well enough meets the most severe requirements
 
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thanks for the replies and info I did fill it today with the GL5 80w-90 that I had and took it out for test run I also had installed new clutch and slave Im not sure if I need to bleed it some more but it doesnt want to go into gear to easily so tomorrow I am gonna try to bleed it some more and see what happens.
 
If I were running that transmission, I'd probably be running Redline MT-85 or MT-90 or something equivalent in it, depending on temperature. I thought if you run regular GL-5 80w90 gear oil it tends to eat the synchros.

Pennzoil Synchromesh - PERIOD!. These transmissions have brass syncros. GL-5 eats them. I'd even stay away from Redline...
 

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