Changed auto transmission fluid and being a dummy listened to the wrong advice actually both by parts store and dealer. I put in DexronIII/Mercon instead of Mercon V. Now transmission slips. Can I flush it out and put the correct fluid in, or is it too late?
R

What about putting in some Lucas Transmission Fix?

I'm assuming you have an automatic then? How long have you been driving with the wrong fluid? You might be able to just change it out.

I suspect one drain and fill will not get all the old fluid out of the system. I would recommend draining and filling it. Drive it for a bit to get the transmission through all the gears and repeat at least two more times. I don't know how much fluid comes out with each change, so this is only a guess that three will clean it all out. If the fluid capacity is the same as a 1998 Ranger with an automatic, you have 9.5 quarts (4X2) or 9.8 quarts (4X4) to change out.

Some people like to do a flush but I've heard of people having problems after doing that. So I would recommend the drain and fill method.

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Sgtsandman's Work in Progress
2011 Ranger XLT, 4X4, 4 door Super Cab. 4.0L, 5 Speed M50D-R1HD, 3.73:1, 8.8" open differential, Jason Pace cap
2019 Ford Ranger STX FX4, Super Crew, 2.3L Ecoboost, 10 speed automatic, 3.73:1 with rear locker, Leer 100XR cap

I would take it to a transmission or lube shop that has a machine to actually flush it out the right way. Most other DIY ways are not really complete flushes.

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(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
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Let it fuck up your tranny then take it back to the dealer and tell them "fix it, bitches".

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1997 Ford Ranger 2.3L
It's lowered and stuff.
My Build Thread

what year is the ranger? how many miles? did you do a drain and fill or did you disconnect a line and pump it out?

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

It is a 2001 Edge 3.0 4x4 automatic. Bought it used from a local dealer and bought the used car warranty to use in case of this situation arising. Original trans started slipping shortly after the the warranty ran out . The same dealer gave me a filter and gasket set and a case of fluid when I bought it with 86,000 miles on it. I was told that this is not a warranty thing but here's the stuff to do it yourself. I went to a local lube center and had a flush done along with new filter. That was 20K ago. It is going on winter so I changed the fluid and filter and the transmission started slipping immediately and after a few test runs started slipping bad. Called around and came to the conclusion it was toast. Found another in a local salvage yard and put it in. Soon this one is slipping too. Trans supposedly had 73k on it. I pulled the pan and cleaned it all up and installed it. A major pain!. After it started slipping I pulled the pan once again and found no large amounts of heavy glitter but the sediment looked more like it had been in there for several thousand mile not about 200. Stuck in a new filter and changed out as much fluid as I could and still slips as though I didn't do anything at all. Sorry about the length of this, but that is the story up to this point.

You can keep swapping out the transmission fluid every week which obviously accomplishes nothing. Or you can take it to a transmission shop and have it fixed. Not sure why you keep doing things to it that aren't going to fix it.

__________________
(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
Info: 300+ intake threads here on FRF
Info: HID Projectors
How To: NO HEAT Troubleshooting Guide

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Used car dealership gave you the fluid & filter and gave you the wrong stuff?

If that's the case, then they should be payin the bill.

Mercon V replaced Merc III..........if your gonna do it yourself, I would recommend goin to your local Ford dealer, get 7 quarts of Merc V, filter, & 2 bottles of XL3 friction modifier.....then do the service.

If it still slips after that, then its gonna need rebuilt/replaced.

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ALL THROTTLE, NO BOTTLE!!!

Daily Driver: 98 Thunderbolt

TOY: Green 94 Pro Street

I always thought the XL3 was only for diffs.?
if not here is some on ebay if can't find it local
http://cgi.ebay.com/ebaymotors/FORD-...Q5fAccessories

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2001 Ranger Edge 4x4 , Stepside,FRF decals, 4.0L SOHC decals, Primus IQ brake controller, curt 2" rec. hitch, custom winch mount,
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No, it's call friction modifier (skunk oil) and does just that...

I put a couple bottles of it in both my Ranger & towpig.

You need to get all the Mercon out before you fill up with Mercon 5 because the two aren't compatible. Now I don't know if that's a corrosion thing, a water absorption thing or a it'll make your transmission slip kinda thing.

Are you experiencing late shifts followed by a rough engagement or what? Define slippage a bit better. Has the 2nd transmission used the same control modules or did those get switched also?

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08 4.0 Sport 4x4
Stock

Yeah I know that if it does a considerable amount of slipping it is a goner. Got the parts coming for rebuilding my original trans from Makco. Besides my boat needs a new anchor. Just thought the off chance it would be savable, ho=hum