I just bought an '88GT with manual five speed, what fluid do you put in it, mine is low and the local Pontiac dealer didn't even know, they just said use manual transmission fluid(like i didn't already know this). Is there a certain brand or weight I have to use, plmk what you use, thanks..jim
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10:41 AM
PFF
System Bot
Indiana_resto_guy Member
Posts: 7158 From: Shelbyville, IN USA Registered: Jul 2000
GM recommends Synchromesh for it's manual trannies. Just don't buy it at a GM dealer, they want too much $$$. It's available at Autozone for less than $5 a quart.
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10:50 AM
CC Rider Member
Posts: 2037 From: Cameron Park, Ca Registered: May 2001
I was speaking to the head tech over here at the GM dealership in Oregon, and he said that they have had better luck with the royal purple than the syncromesh. I personally used it in mine and it helped noticably better downshifting into first. The rest seemed about the same. just my .02 cents
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01:00 PM
beachbomb Member
Posts: 1028 From: Screven, GA Registered: May 2000
Is that considered "gear oil"..the 5w10, also where would i find the GM Syncro Mesh at..thanks
NO!! Gear oil is typically 80w to 90w. 5w10 is regular motor oil. As has been stated, the original owners manual says use 5w10 motor oil (same as in the engine, not gear oil and not ATF), but technical bulletins released later said to use Synchromesh.
I used to use motor oil in my transmission and it worked. I now use nothing but Synchromesh and the transmission shifts noticeably smoother.
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07:59 PM
vlatus Member
Posts: 394 From: Raleigh, NC USA Registered: Mar 2003
NO!! Gear oil is typically 80w to 90w. 5w10 is regular motor oil. As has been stated, the original owners manual says use 5w10 motor oil (same as in the engine, not gear oil and not ATF), but technical bulletins released later said to use Synchromesh.
I used to use motor oil in my transmission and it worked. I now use nothing but Synchromesh and the transmission shifts noticeably smoother.
Never seen 5w10 @ Autozone or Advance Auto unless I'm not looking in the right location. You are right, however, in that typical gear oil is 80w to 90w. Red Line MTL and GM Synchomesh ( I wanna say) are both 80w. Shifting is nice w/ Red Line MTL once the tranny is warm. However, it is a pain to get the car into 1st gear at a stop (have to put it into gear before car stops moving. I don't know if this is associated with Red Line, damages synchros, and damage Red Line has caused to my tranny. Tranny was rebuilt about 4 to 5 years ago and 1st gear has always been a bit of a bear.... I doubt it is Red Line as it is compatible (friend checked into this years ago) with GM sychromesh. Apparently, GM uses 'yellow' metals like copper and brass in their trannies. That is why they recommend using GM sychromesh as it has properties designed for those 'yellow' metals. Evidently, Red Line also has the same properties for the 'yellow' metals as does Sychromesh....
If you read the posts, the one said slightly less than 2 quarts, key word there genius is slightly, I was quoting what the actual owners manual said. I'm glad we have people like this on the forum, just keep flipping burgers pal, one day you'll get your "GED" and actually be some-one!!!
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08:47 PM
FieroOilAnalyst Member
Posts: 719 From: Indianapolis, IN US Registered: Feb 2004
Not sure I've heard of any recommendations to use a 5w10 in an engine. 5w20 is the lowest I've seen to be recommended as an engine oil. As low as the viscosity is on a 5w10, this is usually a hydraulic fluid (used in air lines to keep valves lubricated).
Not saying that I'm the duty expert--but that is my opinion.
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09:18 PM
88-DOHC Member
Posts: 442 From: San Jose, CA, USA Registered: Dec 2001
I think the 5W10 is a typo, since its actually suppose to be 5W30 if regular oil is used. But as others have said, GM put out tech bulletins that changed the recommend from 5W30 to Synchromesh when the 5 speed Getrags showed up as options. Prior to that, both the 4 speeds and Isuzu's used 5W30 oil.
And I said slightly less then 2 quarts since thats what mine took when I did it. Besides, it should be obvious that by that statement you would need to buy 2 quarts regardless.
[This message has been edited by 88-DOHC (edited 03-26-2004).]
