Colonel

A couple of weeks ago I noticed that my 4L60-E tranny (it has a TCI shift kit but is otherwise stock) was shifting a bit sloppy. It was quickly getting worse over the course of a couple of days. I thought my stock clutches were finally ready for the dumpster but I REALLY wanted to head to the track that night. I needed a bandaid. Something to hold the tranny through one more night of racing abuse. So, I took it to the local Pennzoil 10 minute oil change and had them do a tranny flush using F-type fluid. Afterwards we checked the fluid level and we noticed that it was two quarts low. See, their fluid exchange is a 1:1 ratio. If it's 2 quarts low to begin with then it'll be two quarts low afterwards. We filled it back up to normal and chalked that up to a leaky line at the tranny cooler. The result? Well, not only was it back to normal (due to getting the level back to normal) but it shifted NOTICABLY better than ever due to the F-type fluid!

This is not the first time I've seen this with F-type fluid. I've used it in all of my 4L60-Es at one point or another. It never fails to deliever quicker and firmer shifts.

quickWS6

I've never seen F-type fluid at a parts store. Do you know any name brands that offer F-type?

Gotta change my fluid/filter soon anyway, might as well give it a shot.

ngozer

iTrader: (1)

hmmm...how long does it hold up using f-type?

Colonel

There are lots of different brands of F-type. Most (maybe all?) of your major brands make it. You should be able to find it at the parts house.

The less the clutches slip the longer they will last. So, clutches should last longer when using F-type than when using Dextron. Dextron fluid was designed to make trannys shift smoothly...not what I want in a performance application.

fastlif

iTrader: (1)

I've always changed over to F type. It just shifts better with it. FLP actually recomended it.

DrkPhx

iTrader: (15)

Be careful with that stuff. It is similar if not the same as B&M Trickshift fluid made specifcally for older trannies that use Dextron II, not III (which they did come out with a newer version). It's has a gritty feel to it. Years ago I used it in my 85Z28 with good results, but I wouldn't put in a newr tranny. It will also void your warranty. Your call.

Colonel

"Be careful with that stuff."

Or what? FLP recommends it. My tranny guy (who's been building them right since before I was born) recommends it. Yank likes it. I've been using it in 4L60-Es since 1999 (and other tranny's long before that) with nothing but good results. Do you know of any tranny failures linked to using F-type fluid?

BTW, I've used Trick Shift before too. IMO, it's just expensive F-type. Seems to perform the same anyway.

Colonel

"It will also void your warranty."

I hadn't thought of that and it's a good point but it begs the question...how are they going to know? If your warranty isn't voided already then you're probably not making enough power to worry with F-type. The Dextron slip-N-slide will work just fine.

ngozer

iTrader: (1)

maybe colonel can jump in again but that gritty feeling is probably friction modifiers. which if you feel them is probably a good thing. yes i know friction leads to heat but you can curve that with a tranny cooler and or a deep pan also friction means less slipping. i may be off on that but it makes sense to me if it reduces slip and if a big time tranny specialist like yank recommends, it i'm gonna go with it.

Colonel

That's exactly why it feels "gritty." It is, thankfully.

Better friction properties means less slippage which means a firmer shift and LESS power converted into heat. It's kinda like letting out the clutch on a manual car slowly. You have less friction while the clutch is not fully applied so the car starts off slowly but you're generating MORE heat overall than if you released the clutch quickly due to more slippage and the process taking longer (more time spent generating heat.)

DrkPhx

iTrader: (15)

Colonel - The dealer could simply check the fluid and have it analyzed if they were inclined to. Even if you changed the fluid back to stock-type there would be some residue. But,you're right a moot point if the warranty is already voided.

I dont' have any links to trannies failing due to F-type. The couple of shops that I talked to including the one who installed my TC specializes in GM trannies didn't recommend using that or B&M. I also had some unexpected tranny work done in SD on my 93 Jimmy by a trans shop who told me the same thing.
Has anyone ever monitored the trans temp to verify it's lower compared to stock-type fluid? I guess to each their own, I will stick with stock type fluid and let the LS1Edit firm up the shifts.

fastlif

iTrader: (1)

using ls1 edit to firm shifts will do more damage than fluid will any day. Increase in line pressure is what kills pumps. But hey people do it everyday. Warranty? what is a warranty?

DrkPhx

iTrader: (15)

I didn't increase line pressure, but just quickened the shifts. The HPP3 will increase just line pressure. There is noticeable difference in how the car shifts between the two.

Jorday

I run type F in my Pro Yank 4L60-E, and have since I got it. Mike from Yank specifically told me to run that, and he also said that it works great in stock 4L60-Es as well.

gator's 99TA

iTrader: (2)

i have noticed that trick shift stuff from B&M is pretty darn good but damn it is too expensive. next time i dump the fluid in my art car 4L60e, no doubt i am going with a f-type tranny fluid. anything to keep the clutches from slipping.

AK's WS6

Can f-type be mixed with dextron for a little less slipage??? Like say you are changing the fluid and you put 4qts of dextron and fill the rest with f-type??

RPM WS6

iTrader: (3)

Odd. I was just at FLP two months ago getting my current trans installed and they didn't mention anything about that. All they (Chuck included) recommened to me was to use NON-synthetic fluid. I told them I use regular DexIII and they said great. They never mentioned anything about Type F.

If they told you to use Type F, why don't they tell that to all their customers? Maybe they fill their trans' with Type F when they install them? As far as I know they used DexIII in mine, they didn't tell me otherwise?

jimmyblue

iTrader: (11)

Trans is designed for Dexron. But, you might have issue
with certain design compromises and decide you like the
effect of different friction modifiers found in Type F. It's
an old Chebby trick and I guess it still works.

quickWS6

Colonel, is there any need to flush the Dextron out of the tranny cooler and converter? Can you just drain the pan and add in the Type-F, or should the entire system be flushed?

Gage

TTT id like to know as well