What kind of tranny fluid for a 5sp?

ekesz13

Registered User
I did a search, and it seams that there is a wide field of preferred choices for manual tranny fluid. The name I saw the most was Mobile 1. Does anyone have any input on this? I just had the tranny rebuilt and am about to load it up. Also, what about the friction modifier? Add or not? Thanks.
 
Right now in the 89 I am running Redline D4 with no friction modifier. The spec. fluid is Ford Dextron II ATF with Friction Modifier.
 
Well today you would Use Dexron III, it replaces Dexron II. The friction modifier will help with the shifts. You can also use the rear differential addative instead of the Ford Friction Modifier (this is what the dealer told me). I used Mobil one ATF with the friction modifer and everything works well.
 
I say don't use Mobil 1 ATF. Because of it's synthetic nature it tends to aerate easily. The beating that the gears in a manual trans will give the fluid will work the Mobil one up into a lot of vapors. I used mobil 1 for a while and every time you ran the car decently hard you could smell the ATF all around the car, and there seemed to be mobil 1 all around the trans, and the floor pan.

I went to a "normal" ATF and all that is better. Shift feel is pretty much the same. I have heard good things about GM's Synchromesh, I tried it for a while and could not really tell a differents as far as shifting goes.

I say follow your owners manual's recommended fluid.
 
I think you might have had another problem, I used it for 2 years without ever having a problem.
 
No, I really don't think so.

As I said, when I drained the fluid and changed to a different type, the smells, and the "ATF condensation" went away. I spoke with a transmission engineer who explained the shorter molecules of the synthetic fluid cause that type of thing. He had observed the same thing in his car with Mobil 1

If you haven't seen it, doesn't mean it doesn't happen. You might not be driving your car very hard, or not paying attention, or maybe are just lucky.

The trans shop that rebuilt my M5R2 recomended either natural straight 30wt engine oil for summertime use, or plain old ATF for year around, and to avoid synthetics.
 
This explains why I am smelling that horrid Ford Friction Modifier after highway driving for a while with this freshly done M5R2. I used Castrol Syntech Dexron/Mercon. I see no leaks at all it must be what Andy said....siiggghhh 40 bucks in synthetic down the drain.
 
Another thing I just remembered (this Mobil 1 thing was a year and a half ago) was that the Mobil 1 seemed to have an adverse chemical reaction with the shifter dust cover that came with the Ripper. The cover was soft and pliable EXCEPT where it had the ATF condensation on it (the top), there it was hard and brittle. This caused it to break apart as the shifter moved, and not cover very much as far as dust is concerned. B&M was good enough to send me a new one, free for the asking.

So Les, if you have the Ripper, you might want to check out that rubber cover that goes right on the shift tower.
 
Andy, the problem with the 30wt is that it is too thick to properly flow through to every thing inside the transmission. (according to my tranny guy). Basicly he was saying it would cause very hard shifting while the tranny is cold.
 
Thanks Andy I don't have the Ripper. I bet it's like you said it's getting aerated like crazy from the gears and shafts and the smell and extra air is venting out of the stink hole(the little vent with the black condom on it right at the top of the tailshaft) and I can smell it in the cab from time to time.
 
Eric - I would go with Duffy and the Redline D4; that's their latest synthetic ATF and, what Redline recommends for our 5 speed trans.
Personaly I've had two 5 speeds ('90 & '93) and driven over 400,000m using Redline 'MTL'; which is their synthetic gear oil that they used to recommend. I also tried adding their synthetic friction modifier as well, with some minor improvement. I think the gear oil gives a little better protection for maybe slightly less shifting improvement over a synthetic ATF. My '90 went 247,000m and my '93 (which my son currently uses) is up to 185,000m without any noise or vibration, even at WOT.
My 2 cents,
Jim.
 
Thanks for the input

Okay guys, thanks for the info. I see that there is really no concensus on this. Let me throw one more into the mix. A tranny guy in the area (So Cal) that is well know for good work just recommended to me to use a 60/40 ratio of ATF to SYNTHETIC MOTOR OIL. Does this sound right? I even asked twice if he meant MOTOR OIL and he said yes. He said it does not need friction modifier since there are no clutches in it like a posi rear end (doesn't Ford recommend it?). Whats the take on this? Man, I just wanted to fill 'er up and go :D Don't know exactly what I will do yet, but probably not this. Seems a little wierd to me. I think I will call a Ford mechanic that I know. More to come I am sure.
 
I bought it local but Summit sells it. I was trying to quiet my treanny which had developed some what appeared to be gear noise at like 125K miles. It did quiet the noise some.
 
Unless you changed blocker rings you basically DO have clutches or clutch like material in the M5R2. Given friction modifier tends to "slick up" the lubricant used, you are likely to experience more blocker ring wear if you do not use friction modifier as noted by Ford as being needed.
 
Update, talked to Ford

Just talked to Ford. Obviously they recommend ATF for the 5-spd. They DO NOT recommend friction modifier. It is not needed they said since no friction parts (i.e clutches) in the manual trans. I called a couple tranny shops and they said the same thing. I think I might go with the Redline D4. I found it one place online for $8.00 (a quart?) they did not list the volume. How much do we need again? Is this a decent price?

EDIT- Sorry, just read Duffy's post. Guess I will add the friction modifier, couldn't hurt right. I wonder why this Ford dealership said "no" to the modifier? Go figure.
 
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Some manual trannies do not have fiber blocker rings. These basically have a surface of clutch like material on the face of the ring. Obviously the dealer you spoke to knows about the same about SC's as most dealers...which means nada.

If you use Redline D4 no friction modifier is required. If you use conventional ATF then you do need friction modifier.
 
This is from my 94 factory service manual. Read number 15 on the right hand side. You'll see it does call for friction modifier to be added with the transmission fluid.

Frictio1.jpg
 
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