# Man. Tranny/Diff oil



## khurst (Nov 13, 2009)

Need to change the tranny and diff oil (05, LS2 6 Speed) only 9K miles but as advised from the members here want to change it out. What is the capacity and weight I need for the axle and tranny? I know I'll need to add friction modifier but not sure how much of that to add with the diff oil. Any info appreciated. 

Is it pretty easy to drain and refill and tips/tricks to help appreciated also?

Kirk
Corpus Christi, TX


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## jpalamar (Jul 22, 2008)

M6 you can get the fluid cheapest at Maryland Speed. 4.5ish quarts cap. I used Royal Purple w/ Synromesh

Rear figg needs less then 2 quarts that I just bought at Pep Boys cause it was local. Royal Purple rear dif fluid(already pre mixed with friction mod so its ready to go.)

There are other brands but I wanted to give RP a try. No issues yet with it and it is very easy to get ahold of.


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## B-ville Goat (Oct 5, 2008)

+1 on the RP fluids. I have had them in my '05 for 3 years now with no problems. Some do need additional friction modifier in the rear, I did not and have had no issues. The SynchroMax is great stuff and will smooth out the M6's shifting real nice. I use 85w140 in my car, depending on your location and whether you drive the car in the winter, you may want to go with 75w90(I think that's what the weight is).


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## jpalamar (Jul 22, 2008)

Its funny cause our owners manual states to use 75-140 for the rear but GM discontinued it and now states to use 75w90... I stuck with the 75-140 though.


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## GM4life (Mar 18, 2007)

khurst said:


> Need to change the tranny and diff oil (05, LS2 6 Speed) only 9K miles but as advised from the members here want to change it out. What is the capacity and weight I need for the axle and tranny? I know I'll need to add friction modifier but not sure how much of that to add with the diff oil. Any info appreciated.
> 
> Is it pretty easy to drain and refill and tips/tricks to help appreciated also?
> 
> ...


Search around on the forum you should be able to find the capacity and tips on how to change out the fluids. I'm using Dextron VI in my tranny and the stock fluid in my diff. I've used Royal Purple in my old diff, I can't say too much about it because it didn't stay in there long.


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## MTUGTO (Jan 22, 2010)

I put Mobil 1 in my trans and it still has a hard 1-2 shift when its ice cold out, see my local, but seems to be butter smooth in other gears once warm. Put Mobil 1 in my diff, 1.6 qts, I believe, with Ford friction modifier since its a cone LSD. But perhaps I added the wrong amt as I get bad one wheel spin unless I'm rolling in a straight, then both grab...


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## batmans (Aug 16, 2007)

Is there any risk of damaging the reverse sensor when filling from here?


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## jpalamar (Jul 22, 2008)

batmans said:


> Is there any risk of damaging the reverse sensor when filling from here?


Thats were I filled mine.


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## GM4life (Mar 18, 2007)

batmans said:


> Is there any risk of damaging the reverse sensor when filling from here?


Thats where you suppose to fill it.


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## batmans (Aug 16, 2007)

Why are their 2 fill plugs?

I've been driving with just the lower fill plug used for the last 40k miles.

Any damages?

Is the reverse light fill for lubricating the shifter portion?


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## GM4life (Mar 18, 2007)

batmans said:


> Why are their 2 fill plugs?
> 
> I've been driving with just the lower fill plug used for the last 40k miles.
> 
> ...


GM calls out to fill it at the reverse switch. It don't matter where you fill it as long as you get the required amount in there. When I had the tranny out the fill switch on the driverside is alittle lower than the fill reverse switch side. Some folks have filled it on the drivers side without any problems.


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