90_4x4_4.9I6

Anyone know why a mechanic would recommend atf+4 in an e4od when the dipstick says mercon? Thanks in advance

Just call me Sean

iTrader: (1)

Not sure of the difference. I have heard of using type F though, to firm up the shifts.

armstrong4x4

I'd stick with mercon if that's what it calls for

qdeezie

Maybe he recommended it because its synthetic, but you need to stick with Mercon. E4ODs will let you know quickly if you put a junk ATF in it. Does the ATF4 he is recommending meet Mercon specs?

sylver91

ATF IV is just the synthetic stuff. Most of the bottles will have labels on them telling you whether its compatible with Merc III and other applications but I do believe it is.

Not exactly relevant but I did do a flush on a 99 GMC 1500 last week and it called for ATF +4 being the new standard and since its reverse compatible with DEX III.

90_4x4_4.9I6

Thanks for the info guys. He did my flywheel and flushed my tranny. Refilled with atf 4 and now shifts hard from 1st to 2nd. But from reading this site that is caused by a number of things I need to look into.
Thanks glad I stumbled upon this site to help with my 90 lariet.

90_4x4_4.9I6

Not sure but I will look into it

qdeezie

Just an FYI, my 90 Lariat shifts silky smooth with Valvoline Maxlife ATF. I tried other fluids and had that rough 1-2 shift that you're mentioning.