How can a 1993 Manual Tranny have gear oil in it instead of Mercon?

[RiverRatRanger]

Bought this very used Ranger 5 years ago. Has always shifted fine but thought I should change it for general maintenance. Instead of Mercon which is the only thing supposed to be in a 93 out came gear oil! Would a 91 or 92 have bolted in for a previous owner? Or would the transmission meant to run on Mercon work fine for years on 90 weight?

 

[adsm08]

The 4-cylinder was using the M5OD trans from 88 on, so it is unlikely it had a 91 or 92 trans put in that should have gear oil.

While it is not ideal it is possible to run an M5OD on gear oil and not destroy it.

 

[Denisefwd93]

Maybe the Mercon that old it turned into whatever?

 

[RiverRatRanger]

Maybe the Mercon that old it turned into whatever?

I could wish, but no. I know the smell and appearance of gear oil very well. Plus, there were very few metal shavings stuck to the magnetic drain plug.

 

[Dirtman]

The smell of gear oil always makes me have to poop or some reason. True story.

 

[Denisefwd93]

Somehow humor gets lost without emoticons ???

Adsm that is a surprise coming from you ? that they can could work on gear oil, that always gets me to wondering about synchros, are they supposed to be free or sluggish because of the lubricant?

 

[Mac]

Chart up in tech library still shows the 92 trans using gear oil, maybe someone did swap out. Lot of people still think gear oil belongs in a manual.

Mitsubishi FM146	D​		1988-1992 2.9L Ranger 4X4
Mitsubishi FM132	D​		1988-1992 2.9L 2WD	5-Speed​

 

[fastpakr]

Those entries in the chart are for the transmission that was only behind the 2.9.

 

[RiverRatRanger]

The 4-cylinder was using the M5OD trans from 88 on, so it is unlikely it had a 91 or 92 trans put in that should have gear oil.

While it is not ideal it is possible to run an M5OD on gear oil and not destroy it.

According to my Chilton 91 and 92 trans for the 4 Cyl Ranger used gear oil. That's why I wondered

 

[adsm08]

Somehow humor gets lost without emoticons ???

Adsm that is a surprise coming from you ? that they can could work on gear oil, that always gets me to wondering about synchros, are they supposed to be free or sluggish because of the lubricant?

I said it was less than ideal. I also said you maybe might not blow it up.

Synchros should be pretty free.

 

[RiverRatRanger]

All I can say it's worked fine for years in there including pulling a small RV. But we'll see.

 

[Ranger850]

I worked at a brake shop for a few years (2004 was my last) and we put 90w gear oil in every rear end that need fluid.

The smell of gear oil always makes me have to poop

same

 

[Curious Hound]

But this thread is about the transmission. Not the rear end.

My best advice is; make sure you know what model transmission you have and use the manufacturer recommended fluid for that transmission. Regardless of what WAS in there, you now have the opportunity to make it right.

 

[racsan]

My 94 had gear oil in it when I first got it. Didn’t have any atf on hand when I discovered it but did have plenty of 303 tractor hydraulic fluid, since atf is basically a hydraulic fluid itself , I put that in until I could get the right oil, may have helped to flush the wrong stuff out of the transmission. It seemed to be fine with the 303 oil but I didn’t want to chance it, changing a transmission is never fun.

 

[Ranger850]

But this thread is about the transmission. Not the rear end.

oh yeah. right.