I am wanting to change the fluids in my 1990 4wd ranger. What are the recemented gear oils to use? Thanks

 

1990 4x4 Ranger with 2.3l or 2.9l engine would have a Mitsubishi FM146 and would use 80-90w gear oil, 4.8pints
1990 4x4 Ranger with 4.0l engine would have an M5OD-R1 and use ATF, Mercon V, 2.8quarts
(Look under the Ranger at the bottom of the trans, if you see a bolt on pan its an FM146, no pan an M5R1)

Transfer case in either, ATF, Mercon V, or DEXRON II in 1990, your choice, 2.5pints

Front and rear Differentials, 80-90w gear oil, front 2-3quarts, rear 2-3quarts
Rear axles can be Limited Slip so need a Friction Modifier added, 4 ounces

 

Its the 2.9 engine. Your help explains why I was seeing two different fluids for the transmission. Merry Christmas!!

 

Here is the tag on the side of transmission will this confirm its a Mitsubishi FM146

 

E87A-PG shows it to be an M5R1 on this site: https://core-shifters.com/pages/ford-truck-trans-tag-id
Grain of salt, just because its on the internet doesn't make it right/true, Ford says it should be an FM146, which also doesn't make it right/true, lol

This is why you need to look at it to confirm what it is

FM146 will look like this: https://www.therangerstation.com/tec...ages/FM146.JPG
See the flat part at the bottom behind the removable bell housing, that's a removable pan/cover, can't miss it

M5R1 seen here: https://www.explorerforum.com/forums...ide-jpg.55171/
No opening/plate at the bottom, no removable bell housing, its all one piece back to tail shaft

 

The pictures helped for sure. It is a M5R1. Are the two transmissions interchangeable? I wonder if someone did a swap.

 

Here is the tag on the transfer case what does it tell me?

 

On paper the FM146 was used in all 1988-1992 2.9L Ranger 4X4s

The M5R1 wasn't used until 1990 with 4.0l engine Rangers, 2WD or 4x4
But the 2.9l and 4.0l engines used the same block pattern for bell housings, so people did swap in the M5R1 if the FM146 had a problem
Some Parts were/are hard to get for the FM146, the M5R1 was use until 2011 so parts are easier to come by
And most agree the M5R1 was a much better transmission than the FM series

 

Transfer cases were either BW1350 or BW1354 in Rangers, BW1354 were used 1990 and up on most 4x4s, up thru 2011
BW is Borg Warner

Could be the swap was both trans and transfer case or just the trans, Date on tag is F0 which is 1990, and its a 1354 model
Ford Date codes
D = 197
E = 198
F = 199
(it change to a different format in 1999, F8 was the last year for this format, just FYI)

D5 would be 1975
E8 would be 1988
F3 would be 1993
F0 = 1990

Date codes are NOT related to the year of the vehicle, a date code in a part number is when that part was first made as is, if the part was redesigned then Ford changes the date code to the year it was changed, and it stays that way until it is redesign again as needed
So a Bushing that was last designed in 1978(D8) could be found in a 2023 vehicle