Switch from MerconV to Type F to salvage a slipping trans?

[dwcopple]

4r70w in my Stang GT is slipping when babied. Shifts awesome when beat on. Should I try a drain and fill or 3 with some type F before I have to spend the big $$$ on a trans rebuild?

 

[brianl703]

I've heard (and experienced) that the valve body bolts on those 4R70W sometimes need to be retorqued.

 

[slacktide_bitog]

When is the last time you changed it?

If it's slipping, it's probably too late, but you can try Lubegard or maybe Redline D4

It sounds like you have a drain plug, which is good

 

[dwcopple]

I just replaced the 1-2 accumulator piston and spring, the shift solenoids, the filter, cleaned the magnet, and installed a new pan with drainplug. At the end of summer. What fluid would you recommend I try? Car is stored until Spring but wanna try something as a possible cheap fix, if I can. Car only has 139k on it.

 

[ripcord]

Whoa, that's a lot of friction material in that pan. My guess is the frictions are probably toast. You might eke a few more miles with some Lucas transmission goo. It increases the viscosity of the fluid so there's higher apply pressure when shifting. It's not going to fix anything, though, and if it helps, it's just kicking the can down the road a bit.

 

[Lubener]

Just run it. Nothing is going to add new friction material where it has worn off.

 

[mattd]

That is a TON of friction material in that pan. It needs an overhaul . No magic elixir is going to fix it.

 

[dwcopple]

That is a TON of friction material in that pan. It needs an overhaul . No magic elixir is going to fix it.

Every trans guy I showed that pic to said it was normal for a pan that'd never been dropped before. My plastic plug was still in there when I dropped it.

 

[dwcopple]

Just run it. Nothing is going to add new friction material where it has worn off.

Run what? Type F? Lucas? What?

 

[mattd]

Not any that I have done . Even your symptoms of slipping are telling you something isn’t right.

 

[zrxkawboy]

So you’re saying it doesn’t slip with full throttle?

 

[Fordiesel69]

In all gears or OD?

If just OD then it is a common problem on 98~00 and was finally fixed in 2001. There are some mods ou can do to firm up the OD.

If all gears then above is correct, too much friction material has worn off.

 

[ripcord]

Paging Dr. clinebarger

 

[dwcopple]

So you’re saying it doesn’t slip with full throttle?

Correct. Shifts firm & fast when hammered on

 

[zrxkawboy]

Correct. Shifts firm & fast when hammered on

I'm sure no transmission expert, but it seems strange that it would be capable of this if it were worn out.

 

[Lubener]

Run what? Type F? Lucas? What?

Drive it with what you have in there. The transmission is already in a damaged state and on borrowed time. There's no long term fix for slipping, worn out clutches. I can try cartoon illustration if you need further clarification.

I have never had that much material on the bottom of my transmission pans ever, including a 4R70W transmission.

 

[Greasymechtech]

Drain 24oz and add a bottle Lucas Transmission Fix.

 

[dwcopple]

I'm sure no transmission expert, but it seems strange that it would be capable of this if it were worn out.

That's what I'm screamin!

 

[supton]

I'm sure no transmission expert, but it seems strange that it would be capable of this if it were worn out.

I’m of the same opinion.

Is there a TV cable? something that adjusts line pressure. Wonder if that is out of whack. or just a worn pump, or something else that won’t build good pressure at low engine rpm, but does ok (or good enough) with some revs.

 

[Kira]

Or maybe, just maybe, you're unit is a candidate for a "soft parts" rebuild?

Doesn't romping on an automatic result in just plain wear?