changing all fluids

[therealdeal770]

after reading this part of the forum ive decided to change all fluids in my 00s10 and my 97cavalier.with 127k on the s10 and 173k on the cavalier i guess its about time to change something besides the oil.i have 2 questions. the manual transmission in my truck is a nv1500 5 speed and i know it says to use Synchromesh fluid but i remember seeing something about adding a bottle of friction modifier.anyone know where i can get this stuff.also what weight oil should i use in the rear.

 

[labman]

If it ain't broke, don't fix it. I would stick to what the manual recommends. Too many tales here of people causing more problems than they solve doing things they didn't have to.

 

[unDummy]

Read your owners manual if you have it.
When in doubt, contact the dealer and use the OEM fluid.

I'd grab the fluids from Redline/Amsoil/SF/RoyalPurple/.... and not worry about it.

 

[dailydriver]

If I'm not mistaken there are multiple GM Synchromesh fluids available. I believe one variant does contain a friction modifier. Anyone know for sure?
I also would consider using one of Specialty Formulations (molakule's) fluids. Many have had great results with them (smoother, grind free shifting, etc.).

 

[unDummy]

Yep, the RoyalPurple is good stuff. But, I think that the RP synchromax is a little thin for the manual transmission.
Better off buying a boutique fluid online for the transmission, if you can't find any of the below at your favorite speed/4x4 shop.

I'd use the RP Maxgear in the rearend. Mobil 1/Pennzoil also have GL5 synthetic gearoils at some stores.

RP ATF is good also.

Siphon/refill is excellent for the PS and BF.
But, the brakes still need to be bled every year and at every brake job.

For the manual transmission requiring Pennzoil Synchromesh, try one of these:
Amsoil MTF
Redline MTL
Torco MTF-R
SF Synchroglide or MTL-P

 

[therealdeal770]

well i got the brake and the power steering fluid changed today.i just siphoned the resovoirs dry with a pump and refilled .im gonna do this at every oil change for the next year or so to make sure i get all new fluid in there. i cant find the transmission fluid anywhere.i did find some royal purple synchromax.is this the same as synchromesh fluid.i found out the rear calls for 80w90.whats a good brand.is the royal purple maxgear good stuff.one more question how do i go about getting all the old transmission fluid out of my cavalier.im going with the royal purple maxatf and dont want it mixed with much of the old stuff if i can help it.is taking the pan off enough to get most of the old stuff out of there.

 

[therealdeal770]

little update i got the rearend fluid changed out today with valvoline80w90.seems to feel smoother but it could just be in my head.still haveing trouble finding the synchromesh transmission fluid and really done wanna order anyhing offline cause i dont have a credit card and most places wont take anything else. i was looking on the amsoil site at this oil and see that its listed as a 5w30.would a good 5w30 motor oil work.
https://www.amsoil.com/storefront/mtf.aspx

 

[therealdeal770]

well i went ahead and went with gm synchromesh at 10 bucks a quart,ouch.on top of that i spilled half a quart so i gotta go get 1 more quart to top it off.still hae the input shaft bearing noise that ive had since the truck had about 40k on it.was hoping the fluid change would clear it up.wonder if adding a quart of 90wt would help clear things up.

 

[John_E]

quote:

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Originally posted by labman:
If it ain't broke, don't fix it. I would stick to what the manual recommends. Too many tales here of people causing more problems than they solve doing things they didn't have to.

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I concur sometimes, but not always. ZF claims the ATF in their automatic transmissions is "lifetime," but I have heard several horror stories of failure at the 80 to 100k mi / 130 to 160k km mark.