4r70w front seal leak questions

[RLWatHCSA]

I just got this 97 xlt awd 5.0 with 4r70w, and first thing i noticed was it took a second to ingage in drive. i drove it around for a few and after a while, it slipped when trying to go from being at a stop sign. I checked fluid and is was real low so when i looked under, it was leaking out the front seal. It drove fine for a while with no issues other than the delay putting it in drive until it slipped. I was wondering with 200k on it and what its current issues are, what needs fixed in this tranny. Reccommendations on what should be replaced or fixed would be appreciated. TIA

 

[BrooklynBay]

Welcome to this forum! It has a lot of mileage so it's possible that it might need to be rebuilt in the near future. If you are going to remove the transmission to replace the front seal, then it would be a good time to rebuild it.

 

[410Fortune]

Automatic transmissions wear out.
200K is a LONG life for that transmission in a 4500# suv.
The transmission needs to be removed and rebuilt.
the transmission cooling system needs to be flushed.
The rebuilt transmission and new torque converter need to then be re-installed and tested.
After a break in period the filter and fluid should then be changed again.

Then you will be ready for another 200K miles as long as you keep the transmission cool and use a reputable builder, make sure to get a warranty

 

[Cobraguy]

And I would try and start with a core from a 1999 or later if possible. There are some upgrades in those that are desirable.

 

[JerseyBear]

BUMP!

I have a similar problem with my 97 Ex 5.0 XLT that has gotten worse today. I've checked here and other online forums, not to mention other online searches. Also the Haynes manual doesn't go in depth.

Backstory-
My wife and I have a mini farm, the Ex has served us well, kept up with general maintenance, parts when needed but never did anything with the 4r70w. Bought it used 3yrs ago with a rebuilt motor-which was done horribly and/or in a rush with what I've seen outside and inside it with oil changes-, been through a few fuel pumps til the last one which wasn't an advance AP part... ty rock auto, shifter bushing-it was tied in place with bale twine...amazed the stub never broke most recent was new injectors, DIS packs, wires and filler neck. It's towed numerous trailers full of hay for our horses-mare had a foal 6mos ago- plus our pregnant mare last year, our move two years with multiple trailer trips and it's been an absolute champ.....til today sadly.

Past few days I've noticed a burning oil smell, opened hood and thought maybe the PCV was in need of service and on a 5.0 it's a PITA....sadly I noticed transmission oil leaking from the bell housing. Mainly work travel til we need animal feed and essentials so it wasn't leaking a lot BUT when heading over the mountain to get straw it started smelling worse from burning more of the ATF. After making the trip back to my start point which is 8mi from home, I took a pic.

I usually don't push the ex to save fuel, I've gotten 400mi to a tank before but I avg 18 to 20mpg. Based upon all that, does it sound like a front pump seal or rebuild? I've yet to check the lines and tube BUT I've seen it drip directly from the bell. Weather holds good I'll try to take and post more pics. Last time I had a trans issue was in my 88 Grand Marquis and it was a rebuild over 12yrs ago due to a dryrotted trans cable bushing at the throttle body and it cost 1400.
We ain't got a garage and me being a local coal hauler for half the day, time ain't on my side either.

 

[Cobraguy]

Front pump leaks can be from several reasons...converter seal, pump seal, converter wear, converter seal has fallen out, etc etc. The only way to find out is to pull the trans and inspect it. At that point...with that many miles...I would probably get it rebuilt. Where time is of the essence for you, just buy a rebuilt trans and converter from a reputable rebuilder and send back the core.

 

[410Fortune]

Well first make sure it’s not a busted cooler line or fitting

Make sure the converter drain is not leaking (not likely but we have to check)

Once you determine where the leak is coming from then can move forward. Leaky front pump seal can be replaced just the seal, but depending on your miles and fluid condition, what is found in the pan it maybe just time for a reman

 

[JerseyBear]

I appreciate y'all's help and feedback, glad I use this place as my go-to for problems with my explorer and TBH if I tear into my Merc GM itll help some.

I've only added a small amount of fluid, it is a brilliant new color, no slipping at all, hesitation, flares, etc that I've had in trans I've known will go or simply changed the filter and it ran fine til something major happened in the vehicle at the time which forced a new cheap vehicle....back when I was much younger.

That being said I'll start simple if there's time this weekend and at least drop the pan and take a few pics. Trans lines are in excellent shape and color which brings me to it being a replacement or just very well maintained. It's been a WV truck it's whole life, sold in Huntington back in the day. When purchased I had no maintenance records passed on so it's been fun to say the least. Wife and I dived under to see with daylight what's going on and with her trans rebuild experience she thinks it's somewhere in the bell housing, which men's pulling and poking around. As you can see in the pics, pan and around the lines aren't leaking but where it makes to the motor and converter drain plug is wet. OP gasket probably needs done but if I had time and a garage to keep it safe from perk-possums, meth monkeys and five-finger discount crackheads, I'd have our car up to par so the Ex could get the TLC it needs now plus more thanks to it's service it's given.

 

[410Fortune]

Are you sure that’s atf? Usually the 5.0
Leaks oil there from the valve covers and the rear main seal

If it is Mercon v for sure then you may consider just changing the front pump seal. Have to drop trans and converter for that.
With the converter off the trans you can check the hub for any grooves that the seal that May have worn into the hub. If you have a groove then there are steps that can be taken to ensure the new seal Does not leak. If no groove then maybe just a new seal will do the trick

Again 95% of leaks right there are oil
Usually from a rear main seal that has let go, the 5.0 rms rides right above the cat converters and those suckers can get hot = leaks

 

[Cobraguy]

Looks red to me from a couple of those photos...

The drain plug was a good idea. That is easy to check. Pull the inspection cover and take a peek. But the last two 4R70W converters I had didn't have one...

 

[410Fortune]

From the factory they had a drain, aftermarket nope

 

[JerseyBear]

Sadly it'll have to wait but yes it's red, oil, coolant and trans all have excellent color. I thought it was an oil leak at first too, I've changed the PCV which is a hand wrenching PITA but I though maybe it had clogged from lack of a breather filter....why it was left out in their rebuild is beyond me and also cheap to buy. No fluid drop noted either BUT if it's engine oil I'd still have to drop the trans and get to it either way. Bet it'd be a good idea to do both depending on age/wear.

Wife's ex is an absolute moron, he wanted to go-to Penco tech back in the day but she did all his work, his loss my gain so she'll be an asset in this endeavor as well as y'all's knowledge.

 

[410Fortune]

Check the breather vent of the trans make sure it is clear

If the breather was plugged it could force fluid out past the seal

 

[JerseyBear]

Breather back on the tail end is free, spins when I twist it. One thing I did check yesterday when underneath, plus it's not wet. Infigure that's the only one and if it isn't then I'll be back under there very soon

 

[410Fortune]

There is only one vent yea and it’s near the tail

Make sure the hose is not plugged w dirt
Or bugs the trans case must be able to breathe

 

[Cobraguy]

Wait...that breather should be connected to hard tubing. I'm trying to recall. I built one of these for my 68 Torino and I'm almost positive there is a hard tubing that makes a loop and drops down by the front of the trans. Wish I could remember for sure how that goes... Maybe that hard tube is a 4X4 option??

 

[410Fortune]

It’s a metal stub about 2” long, 90 degree coming out of trans.. from there it goes rubber up to a metal line that hangs on the bellhousing bolts

Not often are the piugged up with dust or mudd or bugs, but when you have a fps leak this is the first thing to check

 

[JerseyBear]

I'll have to check it, thought it was just the button towards the back. Up late ordering seals and filter from rock auto, plan on pulling the pan and going from there hopefully Sunday. Had to work last Saturday and sadly my M-I-L wanted to go shopping Sunday too, which made it leak worse due to the route we took. Been keeping fluid in it, still shifting fine but leaking as well....stinks but at least with the heat wave the windows are down. Any advice on what seals besides torque, fluid pump, output shaft while I'm at it and crankshaft? Couple different ones with varied specs and I doubt Haynes has the specs needed

 

[410Fortune]

So you are wanting to replace the rear main seal on the engine
Replace the front pump seal on the transmission
You could also get a transfer case gasket
The pan gasket is re usable

 

[JerseyBear]

So you are wanting to replace the rear main seal on the engine
Replace the front pump seal on the transmission
You could also get a transfer case gasket
The pan gasket is re usable

Considering I've no clue of the filter change history, I figure I'd best use a new one.
How about the torque converter seal or is it a PITA? Basically I wanna have it and not need it than be down completely needing said seal BUT also not waste my time with it out and do what could be done while the opportunity is there ya know.