What trans fluid should i use in my getrag.

I always use GM Synchromesh fluid.

5W30 engine oil was originally specified by GM, but with the development of Syncromesh, GM recommended it instead. Either is acceptable although the engine oil is considerably less expensive.

so 5w30 is good enough right, i heard somewhere else to run atf which is better. I'm not going to spend $15/qt for syncromesh.

I bought some of this this week. Real cheap and when cold weather comes you will thank me. Makes shifting real smooth.

http://shop.advanceautopart...10944&ci_sku=7070062

Spoon

quote Originally posted by ckrummy: so 5w30 is good enough right, i heard somewhere else to run atf which is better. I'm not going to spend $15/qt for syncromesh.

http://www.amsoil.com/storefront/mtf.aspx you can get it for much less than 15$ a quart. You rarely change transmission oil, why cheap out and have a poorly shifting transmission, if you just spend 15$ more and can feel the difference.

quote Originally posted by ckrummy: so 5w30 is good enough right, i heard somewhere else to run atf which is better. I'm not going to spend $15/qt for syncromesh.

The Pennzoil synchromesh is about $6 or $7 per quart. And you only need 2 quarts.

is it really only 2 quarts. i had the transmission out and tipped a bunch of different ways.

quote Originally posted by ckrummy: i heard somewhere else to run atf which is better.

Never run ATF in a manual transmission. It is hydraulic fluid with different properties than engine oil and was never meant to be used in manual transmissions.

quote Originally posted by ckrummy: is it really only 2 quarts.

Yep! The oil capacity of the Getrag 5-speed is 1.9 liters, or 2.0 quarts.

The funny thing is the Haynes manual doesn't list the oil capacity of the Getrag 5-speed. It gives specs for the 4-speed and 5-speed, but neglects to mention that the 5-speed they're talking about is the Isuzu, not the Getrag. I wonder how many Getrag owners have accidentally over-filled their transaxle, because they were following the fill spec for the Isuzu 5-speed?

Oh, and oddly enough, the Haynes manual says you can put Dexron ATF in your Isuzu 5-speed. I'm not sure what's up with that.

[This message has been edited by Blacktree (edited 07-18-2010).]

Discussed this today with an american car garage today and they said dexron, but also that a 20/50 oil was far better and improved shifting

quote Originally posted by ckrummy: so 5w30 is good enough right, i heard somewhere else to run atf which is better. I'm not going to spend $15/qt for syncromesh.

A. never use ATF! see cave, stick
Haynes and "american car garage" is wrong.

B. $15 at dealer maybe... see cave, same article.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 07-19-2010).]

quote Originally posted by Spoon: I bought some of this this week. Real cheap and when cold weather comes you will thank me. Makes shifting real smooth. http://shop.advanceautopart...10944&ci_sku=7070062 Spoon

I didn't realize Advance Auto was now selling Pennzoil Synchromesh, good info. GM changed their recommendation in 1988 for our cars, all Fiero manual transaxles should use synchromesh. I changed my '86 GT 5spd. Muncie/Getrag to Pennzoil synchromesh and cold weather shifting was greatly improved. You could get by with regular engine oil but synchromesh is so much more than that. You can read the specs. here and decide for yourself (.pdf file):

http://www.pennzoil.com/doc...%20Trans%20Fluid.pdf

Synchromesh isn't all that expensive but transaxles can be so I don't see the point of using anything else.

Mike

Not sure why anyone would put anything other than what was recommended by the manufacturer in their gearbox. That's like saying you know better than the engineers who designed the transmission. Putting ATF in a transmission that was designed for motor oil is a crap-shoot at best. I don't pretend to know all of the reasons why it would be foolhardy, and I'm sure there are lots of people who will chime in with "I've been running ATF for a million miles", but bear these few facts in mind:

1. ATF wasn't designed with syncronizers in mind, especially bronze/brass syncros. The additives to ATF (including sulphur based additives) can form a chemical bond to brass/bronze and then peel off later causing foreign object damage. Some later manual transmissions do indeed use ATF under the recommendation of the manufactuer, but these use alternative materials. But I'm not sure I'd take the recommedation of a local mechanic over that of GM/Munice/Getrag engineers;

2. Transmissions are designed for a specific weight or range of weight oils depending on the contact patches and operating pressure between mating components. If you reduce the viscosity of the oil below the design point, you'll lose the thin protective film between the gears and you'll have metal to metal contact without lubricant. From the internet: At 100 C here some viscosities (in Cst):
ATF Dex III = 8
5W30 = 11
10W-30 = 11
10E-40 = 15
10W-50 = 19

Clearly ATF doesn't provide the same level of protection for the gears especially under hard use. Experiment with alternative lubricants all you want, but at least do it with your eyes open.