4r70w front seal leak questions

[410Fortune]

The torque converter seal is called front pump seal
It’s not any harder to change then the engines rear main

 

[Cobraguy]

There is also a front pump seal...it's a large o-ring and thin paper gasket that fits under the front pump assembly and around the housing. It is rare for these to leak...but possible. If you have to pull the pump for any reason, these will have to be replaced. And you just might have to pull it. Check the converter for wear (grooves, etc) If they are there, you MUST replace the converter and bushing in the pump!! If you don't, you will have another leak in no time. With that many miles, I will be shocked if there isn't unacceptable wear.

 

[JK080]

Just to throw this out there, the converters themselves can leak too, we have seen them leak from the pads that the studs are on leak where they are welded to the cover.

 

[Cobraguy]

^^^ Good advice

 

[JerseyBear]

Bump! Well I've had it apart for months now, noticed oil sitting where the front pump seal is, already pulled it & the bottom bolts were rather easy to undo, like 1/4" drive tight. Rest took a good tap to undo, noticed blue threadlocker on each bolt as well but damn near yellow. Seems like the front seal is Ford original or dealer seal. The o ring doesn't look bad, nor does the gasket behind the pump, just flattened & old. Bolts being loose on bottom says it may have just been time.

 

[410Fortune]

Drain that converter it has a plug (I’m sure u know)
Fluid looks nice!
Replace all gaskets and o rings associated w pump
Vaseline or assembly
Lube on the new front pump seal / converter snout before you stab converter
Carefully check converter hub for wear : knicks

 

[JerseyBear]

Wife said the same except draining the fluid. Picked up Valvoline full synthetic max lifeul multi vehicle which covers dexron 2, 3, 6 & CVT but also mercon LV & V. I will need threadlocker for the pump seal bolts right?

 

[JerseyBear]

I've got repair sleeves to new trans filter, even a rear main seal but alas I don't haveuch of anything that'll assist in a flush install & neither are leaking. Will the o ring & gasket need any sealant?

 

[JerseyBear]

TBH I'm hoping it's a quick & less painless install vs uninstall, sure y'all saw the thumb in the pic, plus I'm on my back with the truck on one set ramps, now I've got 2, to get this in and done, miss my truck & its reliability.

 

[410Fortune]

Add a bottle or lubeguard red once all is said and done
That max Life fluid is fine I run it too where Mercon v is called for
I run lubeguard red in all our personal vehicles it adds all the stuff your ford auto needs

Yes thread locker on the bolts
I use Vaseline on all o rings and seals
The pump paper gasket goes on dry can use a couple of dabs of Vaseline to help it stay in place

 

[JerseyBear]

So Lubeguard has what Fords crave?..... Electrolytes? Sounds like Brawno having what plants crave

 

[Cobraguy]

If I'm seeing what I think I'm seeing, that converter is junk. You need a converter and a pump bushing. You MIGHT get away with a speedi sleeve if you can find one, but I wouldn't go that route.

Am I the only one seeing that huge groove in the converter? Also, what are the clearances in the bushing?

 

[JerseyBear]

I'm not sure, I'd have to get under it tomorrow. I'm not sure of the groove you're talking about but I'll post pics tomorrow morning after the weather breaks. The truck developed a leak, just kept pouring fluid in it til it was leaking too much. Shifted fine even with the leak, no shuddering or anything. Bottom pump bolts were kinda loose vs the others when taking it apart though.

 

[410Fortune]

Here

If that is a lip that you can catch w your fingernail and it is where the seal rides then you need a new converter
I don’t use the sleeve kits either
Converter are like $90-140

 

[JerseyBear]

I can catch it with my nail, but it's not sharp at all. I've got two types of pump seals & a speeding sleeve but the sleeve doesn't exactly go over it by hand, have to work it a little. It fits perfectly into the seals, even the existing one, new seals glide right over the groove but the National seal is harder to slip off the TC vs the SKF but doesn't the seal sit further down the shaft of the TC past the groove?

 

[JerseyBear]

Also very little wiggle with the existing seal and the pump resting on the TC covered under the truck with a tarp. My first transmission drop, mostly just filter changes or took it to a shop for rebuild

 

[410Fortune]

I wrote an article on how to properly install the 4r70w
It is part of my 07 ranger Build thread

Consider a new converter call local transmission supply houses see if you can get a deal

 

[JerseyBear]

Is that lip where the seal rides or is it further down the TC shaft?

 

[410Fortune]

I believe the seal is further in on the hub
The groove in your hub appears to be right at the base of the “square notch”
The seal for sure rides at least 1/4-1/2” away from that notch
It’s just a lot of labor to r and r a auto trans so we consider parts cheap expenditures
New converters are cheap parts considering if you still had a leak because of a groove in the hub, you would be dropping the trans again

Ask me
How I know! I’ve had a trans in and out 3-4’times in a week for stuff like this. It used to take me a week just to remove one! Hahahaa

 

[JerseyBear]

Yes man, I see firsthand with no shop, lifts, tools, jacks, etc how much of a PITA it is. Why I ordered everything I might need ahead of time. Actually saw a 4r70w torque converter on FB marketplace in VA back in the summer, just bad work hours prevented a lot of progress. Got hungry animals to feed as well so work is priority. I appreciate everyones help, taking time out to reply & get my Ford back in service. Knowledge y'all have is priceless & thankfully there's an online forum where we can get together for it all.