2001 Ford Explorer Transmission Swap - Seeking Fluid Recs

[batook]

I'm swapping in a used transmission on a friend's 01 Explorer XLT 4.0 V6 with 5R55E 4WD Transmission. The original transmission failed by no longer going into reverse gear. I pulled a replacement with 125k miles from a 2000 Explorer in the pull-a-part that had been in a bad wreck, so with any luck the transmission still has some life left in it. The fluid that drained out of it didn't look terrible, but probably was never changed. Planning to change out the filter when installing it.

I'm wondering what to use in the transmission and transfer case. Ford specs Mercon V in the transmission and regular Mercon in the TC, but I've had good results with Redline and Amsoil synthetics in other vehicles and would be interested in other's experience with any good synthetic substitutes. Hoping to get as much life as possible out of this replacement transmission. Thanks much

 

[Black_Thunder]

I did a trans swap in my parents 05 explorer 4dr a couple years ago, same model transmission, put in a reman and filled with valvoline/napa Mercon V

as long as its mercon V I don't think the brand really matters that much as I think they are all synthetic blends

the reason it failed wasn't fluid related, it would no longer move in drive but would move in 1st 2nd and reverse. I believe one of the sprags in the rear of the transmission broke

I did add an External filter mount with a spin on filter after the trans cooler so that should help keep fluid clean and debris out of the fluid.


Just make sure you change the seal on the transmission on torque converter/pump before you install it, like a 7 to 10 dollar seal and better to change it now before you put it in.

should have a borgwarner transfer case and I've never had an issue with any of mine just running regular whatever brand Mercon in it.

 

[tig1]

M1 ATF has been in my various Ford Trans for the last 25+ years. Never a failure.

 

[92saturnsl2]

Myself, I use Amalie (or Wolf's Head) Univeral Synthetic ATF for all applications except those that require ATF+4 (that is one of the few specs left out of the recommended applications-- probably would work just fine but I'm not the gambling type!).

Amazon has it for $64 / 12 pack with free shipping. I've run it in lots of vehicles, always works great, seems to be a high quality fluid in every way.

 

[JamesBond]

With a junkyard transmission in that vehicle I'd use a cheap merconV and drive it for a few months before I spent $$$ on boutique oil. Any merconV should be decent stuff.

 

[slacktide_bitog]

Ford is too stupid to include a drain plug on their transmissions, so you will need an aftermarket pan that has one. Use Maxlife or Castrol Full Synthetic ATF

 

[dave1251]

Originally Posted by slacktide_bitog
Ford is too stupid to include a drain plug on their transmissions, so you will need an aftermarket pan that has one. Use Maxlife or Castrol Full Synthetic ATF

No matter the vehicle make and model I have purchased the last 17 years did not have one. Thus 4 different manufacturers most be stupid by your logic

OP Valvoline Maxlife ATF.

 

[batook]

Thanks for the replies. I didn't realize the pan didn't have a drain plug--will definitely look into replacing it with one that does. I would venture a guess that the trend away from including transmission drain plugs is correlated to the trend of specifying 'lifetime' fluids... 🙄

I like the idea of running some cheaper Mercon V for a few weeks to flush things out prior to using a pricier synthetic. I've used and like the Lubegard Red additive in Dexron applications...any thoughts on using it with the Mercon V and/or a synthetic fill? Seems like most here are recommending Maxlife or M1 ATF, so I'll probably try to use one of those for the final fill after a few drain and fill flushes with regular Mercon V.

 

[slacktide_bitog]

Originally Posted by dave1251

No matter the vehicle make and model I have purchased the last 17 years did not have one. Thus 4 different manufacturers most be stupid by your logic


Correct.

The Japanese almost always have a transmission drain plug . I know Honda, Toyota, Mazda, and Nissan all provide drain plugs.

The best part is that when Ford owned Mazda and they shared transmissions, the Mazda version had a drain plug while the Ford version didn't

For example, the 4F27E they used extensively in the previous decade, including the Focus and Mazda3. The Mazda has a drain plug, and the Focus doesn't.

GM doesn't typically include a drain plug on their transmissions, except their European transmissions like the 4L30. The 4L30 was used in many GM and even non-GM European cars such as BMW. The European GM cars sold in the US, like the Saturn Astra and Cadillac Catera, do have drain plugs.

Originally Posted by batook
Thanks for the replies. I didn't realize the pan didn't have a drain plug--will definitely look into replacing it with one that does. I would venture a guess that the trend away from including transmission drain plugs is correlated to the trend of specifying 'lifetime' fluids... 🙄

I like the idea of running some cheaper Mercon V for a few weeks to flush things out prior to using a pricier synthetic. I've used and like the Lubegard Red additive in Dexron applications...any thoughts on using it with the Mercon V and/or a synthetic fill? Seems like most here are recommending Maxlife or M1 ATF, so I'll probably try to use one of those for the final fill after a few drain and fill flushes with regular Mercon V.


The lack of a drain plug predates so-called "lifetime" fluid. You do not need to do any drain and fill flushes with regular Mercon V before switching to M1 or Maxlife or any other ATF

 

[Black_Thunder]

Originally Posted by slacktide_bitog
Ford is too stupid to include a drain plug on their transmissions, so you will need an aftermarket pan that has one. Use Maxlife or Castrol Full Synthetic ATF

it varies, some do and some don't.


the 5R55e transmissions do have a drain plug from 2002 on, but no dipstick so you have to fill the pan from underneath.

the 4R100 in my 98 f250 LD has a drain plug, as does my parents 2000 Superduty with the same transmission.

usually if you are draining the fluid you are doing a filter swap anyways so the pan needs to come off as well.


or if you are just draining fluid only you can do so by draining the torque converter as most of those had a drain plug.

 

[slacktide_bitog]

@Black Thunder

even if you still want to drop the pan anyway, the drain plug will still come in handy. Because you can drain from the plug, then drop the (empty) pan. It is still easier and less messy

 

[batook]

Haven't been able to find much on fluid recommendations for the Borg-Warner transfer case in this vehicle. Ford specs regular Mercon, not Mercon V. I have read reports that Mercon V can have bad results in the transfer case, but apparently only when the transfer case is the automatic-engaging clutch type? Many just say to use regular Dex/Merc in there. Would prefer to use a synthetic for better performance but I don't want to use something that will cause damage. Would the M1 or Maxlife ATF be good choices to use in the transfer case? I also have a case of Redline D4 in the garage I could throw in there too. Or just go with regular Dexron/Mercon as specced?

 

[slacktide_bitog]

Originally Posted by batook
Haven't been able to find much on fluid recommendations for the Borg-Warner transfer case in this vehicle. Ford specs regular Mercon, not Mercon V. I have read reports that Mercon V can have bad results in the transfer case, but apparently only when the transfer case is the automatic-engaging clutch type? Many just say to use regular Dex/Merc in there. Would prefer to use a synthetic for better performance but I don't want to use something that will cause damage. Would the M1 or Maxlife ATF be good choices to use in the transfer case? I also have a case of Redline D4 in the garage I could throw in there too. Or just go with regular Dexron/Mercon as specced?


M1 and Maxlife can be used in that T-case with no problem

 

[DONWATERS]

T case gets dex merc and trans gets merc 5. Nothing special. I would only use merc 5, these transmissions are finicky and not very good.

 

[batook]

I like what I've read about Maxlife and am inclined to use it over regular Mercon V, unless anyone has had a bad experience/slipping/failure with their 5R55E transmission using it.
For the transfer case, I'm leaning towards Mobil 1 ATF given its slight thicker viscosity over the Maxlife. Having a hard time going with Ford's recommendation to just use regular Mercon in there...

 

[nthach]

I used Kendall VersaTrans part-synthetic "universal" fluid for a friend's 1998 Explorer with the 5R55. I was tempted to use MaxLife, but Merc V works fine.

 

[ka9mnx]

Pulled transmission with 125k miles and unknown history. Fill with SuperTech Mercon V and run for 100 miles or so. Drain fluid. If it comes out nice and red and smell ok, refill with Mercon V. If not repeat. Mervon V is a hard spec to meet and is usually full or part synthetic. SuperTech would be my choice (or whatever is cheaper) for that vehicle.

Transfer case. Mercon was the original spec but is no longer available. Ford DOES NOT want Mercon V in the transfer case. I went online and purchased the MotorCraft transfer case fluid (XL-12).

 

[stanlee]

I used Castrol Mercon V in my 5r55e but I don't think it matters what brand as long as its Mercon V spec. The Castrol was affordable and available. I bought the truck at 200k as a beater so who knows when or how often it was serviced.but the fluid wasn't burnt and I'm at 235k miles on it so far, still shifts great. Whatever you do DON'T put Mercon V in the transfer case. I used Valvoline transfer case fluid which is spec'd appropriately for Ford transfer cases and it literally eliminated an undiagnosed thump I had on deceleration. The old fluid was black and probably never changed.
As for loosing reverse, that has NOTHING to do with maintenance and there is no "cure" for it. Its an arm inside the tranny that fatigues and breaks off randomly. While it will still drive fine in forward gears that broken arm bouncing around in the transmission will eventually destroy the transmission if you continue to drive it. It is not a reverse "band" as people who try to sell them broke with no reverse often say ("just needs the reverse band replaced"). Transmission actually needs a rebuild to fix properly which cost as much or more than the vehicles with this transmission is worth so junk yard/used is definitely the best solution.

 

[stanlee]

Originally Posted by slacktide_bitog
Ford is too stupid to include a drain plug on their transmissions, so you will need an aftermarket pan that has one. Use Maxlife or Castrol Full Synthetic ATF

No Ford knew people would never change the transmission filter if they could drain the pan without taking it off. This makes it 1000x more likely you will change the fluid AND filter.

 

[slacktide_bitog]

Originally Posted by stanlee
Originally Posted by slacktide_bitog
Ford is too stupid to include a drain plug on their transmissions, so you will need an aftermarket pan that has one. Use Maxlife or Castrol Full Synthetic ATF

No Ford knew people would never change the transmission filter if they could drain the pan without taking it off. This makes it 1000x more likely you will change the fluid AND filter.


I don't think Ford's reason was a noble one like you imply. They are just cheap and stupid. If they wanted you to change the transmission filter THAT bad, then they should've used a spin-on filter

The Saturn S-series has a spin-on filter for the trans, and I think some Subarus do, too. Both have drain plugs.

The Japanese don't seem to care about draining the pan without touching the filter. Most transmission filters don't do much, anyway. You can't even change Honda's filter without taking the trans apart, and there has never been a problem with this. The Ody's frequent trans failures have nothing to do with the filter!

GM typically doesn't include drain plugs in their transmissions, except for their non-US-designed cars, and the units they sell to foreign companies like BMW. The Saturn S-series has a drain plug, but Saturn was run completely separate from the rest of GM at the time.

There is NO GOOD REASON not to include a transmission drain plug