Which oil is best for 5 speed?

HwyStar

HwyStar

Registered User
I know this has been over a few times. I just wanted to know if anyone has changed their minds on what works best. I'm using Pennzoil Synchromesh right now and I'm not excited about the notchy shifts. Any second opinions?
 
I put the synchromesh in mine when I first got it and it was pretty crunchy, put a different used trans in with Mobil 1 synthetic ATF and it seems like it likes it a lot better. But then again I'm comparing two different transmissions so idk how much was just the fluid
 
I've always used Mobil 1 full synthetic ATF with the specified amount of Ford friction modifier in my five speed with good results. Unfortunately, I don't believe there is a magic formula to get rid of the notchiness of the M5R2. It's just the nature of the beast.
 
I used amsoil 0w20 signature series in mine with great results no friction modifier is needed.
 
HwyStar said:
I'll give it a shot. Thanks for the input.
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Let us know which one you decide to go with and how you like it. I used synchromesh in the past and was happy with it...then again there was nothing wrong with the trans I was installing. I just did the fluid change for good measure.

I'll be doing some work in my center console area in the teal car and was probably going to do a fluid change since I'll be able to take the shifter off easily...makes for easy refill.
 
Everyone has an opinion it seems, but the fact is using the OE recommended fluid and FM additive is going to give you the best performance (as Mike already indicated) assuming no other transmission damage, extensive wear, or non OE parts. The M5R2 is not notchy by design. If you use the correct fluid and find that it is still notchy then most likely you have damaged gears and/or syncros or other problems.

I have built and driven more of these M5R2's than probably just about anybody in a wider variety of conditions that probably just about anyone, and my opinion remains. Mercon/Dexron (synthetic is fine) and Ford FM is the best combination, again see preceding paragraph. It's what I run in all my builds/rebuilds.

Most M5R2's have damaged/worn parts so most people are looking for a magic pill to cover up those problems. They may find their drug of choice is different than yours possibly because the nature of the wear/damage inside their transmission is different than yours. Such is the nature of covering up bullet wounds with bandaids and is why people's results vary so much.
 
Excellent points, Dave. It's often thought that replacing the blockers will make it start shifting like new. But, If it's been driven for several months with the gears grinding on every shift then more than likely damage is done to the gears as well. I've seen a few, including some of mine, where tooth edges are worn smooth or rounded off on the synchros. I recommend synchromesh with my blockers because the blocker manufacturer recommended GL5 whch is much too thick for the M5R2 so I stepped it down in weight to Synchromesh w/FM. My testing them with ATF, Valvoline High Mileage, gave me excellent results. I recently rebuilt an M5R2 that had gear oil in it. Every blocker in it was worn out including 1st, 4th, and 5th which tend to outlast 2nd and 3rd 2 to 1.
 
The only reason I ran the amsoil was its weight and lubrication properties. I put it In a transmission that was pretty well new so it wouldn't have had grinding problems in the first place. It worked well but I also agree with Dave in every way.
 
Mike, just FYI, I recently built a very nice M5R2 with your carbon fiber blockers and used the recommended fluid as usual. Had the car at the track shifting aggressively @ 6300rpm with no issues getting all gears with no crunch or abnormal resistance so I'm confident that the stock recommended fluid works well with the carbon fiber too.
 
I'm currently rebuilding my transmission with Mike's blockers. I'm going to try out his recommended fluids... AC Delco Synchromesh and Motorcraft Friction Modifier. I'll report back in a week or so when i get it all buttoned back up.

Here is a picture of my first two gears. 140,000 miles on this trans before the rebuild, blockers 1-2-3 were wore out. Im curious what you guys think about how bad the wear is on these two. average, bad, better than average?

gear 1.jpg

gear 2.jpg
 
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The points of all the teeth look nice. They don't look rounded off. Check the associated teeth on the slider for rounding off.
If you need internal parts I've found that cobratransmission.com carries lots of parts, sliders, gears, bearings, etc, at reasonable prices.
Dave, glad to hear it shifted great for you. I missed 3rd too many times at 6000 so I think it's time to start replacing bearings and sliders on mine. I'll build another one and swap it out this winter. Mine's still going fine after a year, with the OEMs 3rd would be crunching by now.
 
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