changed tranny and rear diff to amsoil synthetic haveing issue's
 

hello i recently decided to flush my manual 6speed tranny and rear diff fluids and use amsoil fully
synthetic manual gear oil in the tranny and severe gear in the diff.

now i did this 2 or 3 months before i put my car away for winter, i remember hearing a whining type
noise which sounded like it was coming from the rear diff, if i let off the gas it would go away then
then i accelerated it would come back for a bit

the gears would some times grind from first to second. sometimes third.
it wasn't that it was colder operating temperature as well and i didn't seem
to have this issue until i switched to synthetic, i may have to switch back to infiniti gear oil.

any ideas if there is an additive that i can put in, what im thinking is maybe the gear oil is now to thin, but that's just a guess.

also,i did use the recommended capacity and viscosity grades that it showed on the amsoil look up

From all the other threads I've read over the years, the G's transmission doesn't like anything other than Nissan fluids. Most drivers who flushed out the fluid and replaced with Nissan fluids and didn't run into problems.

(Correct me if I'm wrong guys.)

You should be using J-Matic (or now S-matic) fluid only.

The OP has a 6Mt not autobox.

Yep...
Been there done that in my 6MT

1st off, I'm a big Amsoil believer, I've used their product for years.
I put in the Amsoil tranny fluid & shifting was immediately rougher.
I had a 1st to 2nd grind (minor)

I put the Nissan MT fluid back in & everything was fine again.

My apologies, I fail. I've been up for over 24 hours, still working. My brain is fried. :dunno:

thanks for all the help,
i thought i was the only one with this issue.
i will have to stop by nissan and pick up my fluids before summer hits

I noticed the exact same thing with Motul fluids. Once the car warms up (5minutes) the sound goes away. The whirling noise happens when im at about 2k rpm. It also happens when I am shifting, if I put the clutch in and bring the shifter into the gate for a gear without actually putting it in gear(also when im actually shifting), the sound happens again. The noise doesnt bother me to much seeing as how once it warms up, it shifts like a hot knife through butter!

just wanted to update, Infiniti/Nissan Fluid in the Transmission and Pennzoil gear oil in the Diff. no more issues
.. not useing ams oil anymore unless its engine oil

I think you meant Infiniti/Nissan Fluid in the Transmission and Pennzoil gear oil in the Diff.


I am planning on using this combo

Tranny

http://i33.tinypic.com/2hs2ej7.jpg


Diff

http://www.lachoppers.com/images/pro...0824164346.jpg

http://img704.imageshack.us/img704/194/dsc01821iz.jpg

I'm not sure what happened to the OP's or the others here, but i've used amsoil in my transmission and rear diff and absolutely made a big improvement over OEM fluids....you guys sure you bought the right ones?

Nissan is cheaper and more people have had better luck with shifting. I can only find one thread but others had the same experience. I am only changing out the fluid as a maintenance item and clean up shifts. I think any fluid you change will make a difference over old fluid but Nissan fluid should help with keeping shifts smooth. The money saved from aftermarket fluid will easily cover the diff fluid :biggthumpup:

https://g35driver.com/forums/v36-eng...options-2.html

thats exactlly what i ment Infiniti/Nissan Fluid in the Transmission and Pennzoil gear oil in the Diff., lol i should look over what i write

yes i did use the correct fluids that ams oil said to use for the 2003 g35 coupe 6mt, i sell this product at my store in ontario canada and figured i would test it out but in my case it made it worse , once i flushed it out and went back to oem product it was smooth shifts and no noise, not saying not to use ams oil product but it dident work in this case for me.

....:icon18:....I don't believe that's advisable in his 6SPD MT as he posted in his first paragraph....sorry Tofu!
Go ahead and run the synthetic for a while, get it hot and if it's still making noise and not allowing the trans to shift like normal switch back to Nissan fluids. This is not the normal results when using quality synthetic....:dunno:
Gary

I have been meaning to change out my 6MT fluid and Dif fluid for the same Amsoil products. I already have them on my shelf but now I am hesitant about doing that.

Is the issue more related to the 6MT fluid? I thought I read good things about the sever gear lube. Should OEM be used in both or mainly just the 6MT?