Haynes specifies 5w30 motor oil for my 85 4 speed. Is that right? Anyone do this?

Brit

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It used to be correct. It will still work but the current correct fluid is "synchromesh" fluid.

lol - yup. I said the same thing when I heard that.
5w30
but, the new spec is for this stuff called "synchromesh"
which is: synthetic 5w-30 with no detergents added

yes - 5w30 plain old, motor oil works. synthetic 5w30 works even better. synhcromesh is the choice stuff.

Plain old engine oil will work, but the synchroes don't like it. It is not slippery enough and you'll get resistance going into gear.

Get the Synchromesh fluid.

Arn

It was supplied from the factory with 5w30, but GM issued a subsequent TSB which changed the recommended fluid to Synchromesh, which can also be purchased under the Valvoline brand IIRC for about half-price. The old oil will work fine, the main advantages to Synchromesh is easier shifting, particularly in very cold weather.

JazzMan

Synchromesh can be bought for about $8.00 a quart.

quote Originally posted by jscott1: Synchromesh can be bought for about $8.00 a quart.

I have some synthetic 5w30 Valvoline. Good enough?

That is fine.. really... my 84 (4 speed) called for 5W-30 (right on the plug).
The syncromesh was promoted for the Getrag (at least a while back).

J.

SYNCHROMESH FLUID
PRODUCT DESCRIPTION
PENNZOIL® SYNCHROMESH FLUID is a synchromesh transmission fluid designed for certain manual transaxles and
manual transmissions used by General Motors or Chrysler. PENNZOIL® SYNCHROMESH FLUID is formulated with
high quality paraffinic base stocks, a fluidity modifier, multifunctional performance additives, corrosion inhibitors, a foam
suppressor and a shear stable viscosity index improver additive. It provides excellent oxidation stability, low temperature
performance, excellent synchronizer performance and compatibility with yellow metals, such as bronze, brass and copper
components found in manual transaxles and transmissions. This product will satisfactorily lubricate General Motors or
Chrysler manual transaxles and transmissions from -40°C to +150°C.
APPLICATION
PENNZOIL® SYNCHROMESH FLUID is specifically formulated for synchromesh transmissions used by General Motors
requiring General Motors Part No. 12345349 (Specification No. 9985648) Synchromesh Transmission Fluid or Chrysler
transmissions requiring Part No. 4874464 (Specification MS-9224). It is also recommended for use in General Motor
transmissions requiring General Motors Part No. 12345577. It is listed in the Pennzoil Lubrication Recommendation And
Capacities Guide as “GLS.” PENNZOIL® SYNCHROMESH FLUID is NOT intended for all GLS applications. You
must verify the manufacturer’s part number, indicated by a superscript number and found at the end of the vehicle
application listing.
BENEFITS
• Exhibits excellent low temperature performance
• Meets GM Specification 9985648
• Suitable for use in GM manual transaxles and transmissions requiring GM Part No. 12345349 or 12345577
• Meets Chrysler specification MS-9224
• Suitable for use in Chrylser transaxles and transmissions requiring Part No. 4874464
• Excellent synchronizer performance
• Excellent yellow metal compatibility

Maybe the foam suppressor is something different.

Always read the manual!

...some time ago Ford made the switch to using Type F automatic transmission fluid in its power steering systems. If you hear a newer (after about 1990) Ford going down the street with its power steering pump howling, there's a good chance that the owner didn't check the manual and put in power steering fluid instead of Type F.

Ford also uses Type F in its manual transaxles.

...which has nothing to do with Fieros, I know. Sorry.

Ed

trust me you will want to use syncromesh ..the superior shift quality by using it is worth the price

quote Originally posted by Erik: trust me you will want to use syncromesh ..the superior shift quality by using it is worth the price

Can you be more specific about what it does. No grinding? or???

I use Mobil 1 Synthetic 5w 30 in crankcase and gearbox. Have for years without difficulty.

quote Originally posted by NashvilleFiero: Can you be more specific about what it does. No grinding? or???

Your transmission will shift more smoothly. It won't be as notchy or difficult to get into gear.

Synchromesh is the best. That is what you want. Use Synchromesh. You'll need 2 or 3 quarts. It's about $10 more than synthetic oil.

quote Originally posted by Formula88: Your transmission will shift more smoothly. It won't be as notchy or difficult to get into gear. Synchromesh is the best. That is what you want. Use Synchromesh. You'll need 2 or 3 quarts. It's about $10 more than synthetic oil.

Might be worth it then. Guess I will go with the off brand Valvoline

quote Originally posted by jconnor34: I use Mobil 1 Synthetic 5w 30 in crankcase and gearbox. Have for years without difficulty.

I recently spoke to Jeff @ Engineered Performance, which makes a LSD for the Getrag 282 trans, and he also recommended using Mobil 1 in my 5-speed trans.
I guess that makes 2 votes for the Mobil 1 as a gearbox lube.

~ Bob

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"Its nice to be important.
Its more important to be nice."

Hmmm...maybe we need to do a comparison of Synchromesh vs Syn somehow. It would not be hard to quick fill and drain.

quote Originally posted by NashvilleFiero: Hmmm...maybe we need to do a comparison of Synchromesh vs Syn somehow. It would not be hard to quick fill and drain.

I tried synth in my Muncie then switch to syncromesh and it was very noticabley smoother shifting ..no more notchy clunky slow shifts

quote Originally posted by Erik: I tried synth in my Muncie then switch to syncromesh and it was very noticabley smoother shifting ..no more notchy clunky slow shifts

EriK,
Could you share with us all which brand of synthetic oil, (and weight), you used originally, and what brand of Synchromesh transmission oil you changed to that made such a big difference.

Thanks
~Bob

quote Originally posted by FieroBobo: EriK, Could you share with us all which brand of synthetic oil, (and weight), you used originally, and what brand of Synchromesh transmission oil you changed to that made such a big difference. Thanks ~Bob

To be honest I first used normal motor oil 5 30 which really sucked ..it was like shifting a tractor then I used Mobile 5w 30 synth which improved the shift but was still clunky notchy feeling and then Penzoil syncromesh which really made a difference ...

quote Originally posted by Erik: To be honest I first used normal motor oil 5 30 which really sucked ..it was like shifting a tractor then I used Mobile 5w 30 synth which improved the shift but was still clunky notchy feeling and then Penzoil syncromesh which really made a difference ...

Erik,
Thanks for sharing the information with us. The sharing of information on this forum is one of the best features of this forum has to offer it's members. Knowing what has, (and has not), worked for others is a great asset. It's great to be able to learn from the experiences of others.

Synopsis: Regualr 5w30 oil ----- Not Good
..............Mobil 1 5w30 -------- Better but still lacking
..............Penzoil Syncromesh -- Much better

Thanks again.
~Bob

quote Originally posted by Erik: To be honest I first used normal motor oil 5 30 which really sucked ..it was like shifting a tractor then I used Mobile 5w 30 synth which improved the shift but was still clunky notchy feeling and then Penzoil syncromesh which really made a difference ...

no offense, but i had the exact opposite effect in my 4 speed. 5w30 mobil 1 shifted significantly smoother than syncromesh. i never tried regular motor oil, just synthetic. the only reason i can attribute this to is the fact that syncromesh is designed for the newer modern manual trannies, which have clutch-disc style syncros in them, whereas the muncie 4 speed is an old design that uses the old style REAL syncros.. syncromesh is friction modified, slightly abrassive, almost like dextron is..

[This message has been edited by stickpony (edited 06-04-2008).]

syncromesh is still tops!...compared to synthetic and 10w-30. It costs more but worth it!

quote Originally posted by rlloz: syncromesh is still tops!...compared to synthetic and 10w-30. It costs more but worth it!

in a getrag, i would whole hartedly agree with you, but i dont think so in a 4 speed. my experience tells me otherwise

For twenty years I've recommended Mobil 5w30 for every application that originally specs ATF, except the obvious AT and PS, anything clutch less. Fluid type consolidation doesn't always mean best.

Synchromesh is good, but I prefer using either Royal Purple or BG Synchroshift (I believe its BG that makes synchroshift). Also, the actual GM stuff works quite well... I had synchromesh in my 92 eclipse and I noticed a difference for about 200 miles, then back to grinding 2nd when cold and being notchy as hell when I shifted. Switched to BG and it worked great, almost like sliding a hot knife through butter when I shifted.

If you are going to spend 6-8 bucks a quart for a pennzoil product, might as well spend an extra couple bucks and go with a better brand. BG runs about 12 a quart I believe. Royal purple is about 10.