Wrong tranny fluid

Alright so i belive i screwed up. i went and and got all the fluids for my 240 a few weeks ago and filled her up and put prob 100 or so miles on her now. ive noticed the tranny is notchy into gears specifically 3rd.

ive noticed i bought 75-90w gl-5 fluid wasnt paying much attention when buying it. i think all the gear oil they had there was gl-5 so i said oh well.. after looking more into it i read that its gonna eat my synchros and bearings and shit. so i think im going to go out and get some amsoil gl-4 and drain this gl-5 stuff to use for the diff

my question is.. did i do irreversable damage to the tranny you think in the 100 or so miles ive put on it? and what would be the best way to get all that crap drained out. not like i can run some gl-4 when dump it. shit aint cheap. lol

suggestions?

GL 5 should be ok to run in an older trans. You can usually always go forward, but not backward with oil, gear oil, etc.

ok sounds good. i have read on other forums that the gl5 is corrosive to the yellow metals in our case the synchros

no where on the bottle said it was backwards compatible (i bought advance auto parts synth blend 75-90) but on the other brands it says its backwards compatible...

and in the fsm it says gl5 for rear end and gl4 for the tranny.. i just wanna be sure im safe. i mean the tranny dont feel the same as it used to.. not as easy to pop into gear when driving

plus after frequenting all the auto parts chains in milwaukee no has gl4 spec gear oil.. where can i find that mt-90 stuff of the amsoil gl4? do i have to order online?

I had nothing but problems using GL5 Mobil 1 75-90 fully synthetic.

I switched to the GL4 specific AMSoil and noticed a night and day difference. Yeah, I know its supposed to be backwards compatible (meaning GL5 meets the standard of GL4) but I don't believe that to be the truth for our specific application. Will it shift? Yes. Will it shift better with GL4? Yes.

I'm not saying GL5 can never be used in a GL4 application. I'm just saying in our specific case, it makes a difference. I found this to be true with Mazda, Nissan, Dodge (Cummins tranny, forget the name off the top of my head) where GL4 is the best fluid.

The Mazda was an RX7 we had issues with, switched from GL5 to GL4, made all the difference. Nissan was SR20 trans (my personal vehicle), again, switched and made all the difference. 3rd instance was coworkers 02 3500 with a cummins, made a night and day difference switching from GL5 to GL4.

3 instances of switching and it making a world of difference...not likely a fluke. All 3 manufactures specified GL4 for trans fluid.

AMSoil GL4 was available at my local parts store. Bumper to bumper.

Thats all the convincing i needed. i will be getting amsoil as soon as i find a store that has it in the milwaukee area... from what i read i dont need to flush it. just put the new stuff in. whatever gl5 is left will be diluted.. ill save the gl5 for my diff. im sure it hasnt wrecked my tranny or anything when i bought the tranny it was running royal purple and shifted bleh like but this cheap advance auto parts crap makes 3rd feel like shit. im afraid to spank it into gears because it seems i have to force abit. so i go gental and its still got a notch to it. nolt 2nd to third do that and sometimes 1st to second. the rest of the gears are fine. they were fine before the fluid change aswell.. well thanks for the input. like i said just gotta find amsoil locally otherwise i gots to order it

Good info Riggle, I stand corrected.