After re-sealing the transmission I put SAE 80/90 oil in the transmission (had it around). Since then, it's hard to shift from 3rd to 2nd. Could that be the different oil? If so, what do you guys think is the best transmission oil for my 5spd?

 

If its the M5OD trans it should have Dexron in it . If you put that heavy of a gear oil in it that would explain the hard shifts .

 

yeah, check what kind of tranny fluid you are supposed to have. See the manual or check with this list. If you do use the wrong fluid you can have those symptoms or worse. No a days you can't assume regular gear oil is what is required.

Good Luck,

Jim Henderson

 

How can I find out exactly what transmission I have and what fluid it takes?

 

Well, I have to agree with the posts that suggested your choice in oil was too thick. I'm not sure where you live, but in the manual trannys that come with ATF in them, that thick oil makes them really hard to shift in cold weather (like the 30-soome degree stuff we have right now).

If you do want to stick with a good oil, maybe even synthetic oil, you can go for 5W-30 or 10W-30 synthetic motor oil to protect your tranny, give you smooth (perhaps even smoother) shifts, and work in cold weather.

You either have (and probably have) a Mazda M5OD (Mazda 5-speed Over Drive) or a Ford ZF tranny, but it would probably only be a ZF if the previous owner put it there.

From brown 4x4's post at
https://www.ford-trucks.com/dcforum/DCForumID39/1773.html :
" It is possible you could have a ZF, but they're very rare in an F-150. Look underneath at the transmission. If the ribs on it run horizontal and vertical, it's the Mazda. The ZF has diagonal ribs. "

:-X12

Just like Ford is using that real thin 5W-20 oil now for a better fleet miles-per-gallon average, the in the M5OD's was probably there to save bunches of gas. For long term protectiong I plan on using a slightly thicker, better lubricating and more protective synthetic motor oil.

Though you may want to do a search through other tranny-related posts before changing it again. I believe I read that Redline makes a synthetic manual transmission fluid that is thinner like ATF, yet made for manuals. Somebody around here liked it (according to the post).

 

[updated:LAST EDITED ON 23-Dec-01 AT 08:32 PM (EST)]Alright! That was a very helpful post! I'll go and see where I can get the thinner (probably synth. 5w20) oil. I'm already noticing the worse gasmileage! Whereas I got over 250 miles on the first tank, I had to switch at 233 miles after the new oil came in!


P.S.: I forgot to ask: how much oil does my tranny take, roughly?

 

[updated:LAST EDITED ON 24-Dec-01 AT 00:02 AM (EST)]7.6 pts. Exactly, this is for the M50D
6.8 pts. For the ZF

 

I would not use a regular engine oil unless the tranny type you have specifies regular oil, a few do. I would recommend you post to the tranny section and describe your truck and any markings or tags you find on the tranny. Then ask them what fluid is required.

Most trannies use the old style gear oil GL5? Some use Automatic transmission Fluid(Dexron, Mercon, Type F and many other flavors), a few, I think light duty use engine oil. It is important to use the correct fluid. The tranny manufacturers spend thounds if not millions of dollars in research to determine which oil to use. the oil companies also spend plenty to make their fluid work in specific applications. To go based upon a guess, is rolling the dice. Sure you will probably get away with using the wrong fluid for awhile. But if and when any damage occurs it will be long enough down the orad that you may not know what caused it. That is why snakeoil makers can get away with their claims.

Engine oil is designed for specific conditions. Most tranny fluids are designed with high shear stress in mind. They usualy are not interchangable for long or under extreme operating conditions.

Like I said, go to thr tranny section and ask what lubricant is required. Or ask your dealer or have a good parts shop look it up. Don't guess.

Good Luck,

Jim Henderson

 

Jim wasn't quite emphatic enough. If you use motor oil in your transmission you WILL destroy it in fairly short order. The M5OD is a marginal transmission at best, why hasten it's demise? Motor oil does not have the ability to lubricate under the conditions found in a transmission. Use a good synthetic ATF or Redline MTL both of which are designed to do the job.

 

I wasn't aware of the apparently large differences in the different oils. I'll make sure I find out what my tranny is and post to the tranny section to find out what oil I need and how much.
Thanks so much for your advice!