Hey folks, here's the deal:

2000 4L80E with a stripped rear fitting (the long nipple one). I know Heli-coil makes kits to fix NPT threads, but they're like $150 for the kit with the special tap. Because of the cost, this is my last resort. Can I tap the fitting hole one size bigger and use a bushing? will the reduced depth of the nipple cause negative effects/long-term damage to the transmission? alternatively, does anyone know of "oversized" rear nipple fittings? ( I've not found any online yet.)

The transmission is not going to be used for a serious race vehicle or extreme off-roader, more likely just an overbuilt street/dirt road truck that pulls a camper once in a while. I would post pics but the case isn't here with me at the moment.

thanks in advance for any help and insight.

 

So, the 80e is unique with this fitting.

If you don't use the long fitting in the rear, you'll burn up the clutch packs. That fitting provides fluid for cooling/lubrication/etc for the clutch packs. (thanks to transbuilderguy for his FB post referencing this)

Your best bet is to try and heli-coil it and use the long fitting. I'm not sure what bushing you are referencing.

 

That long fitting needs to go inside a hole in the center support to lubricate what's inside there. If the return oil doesn't reach that area you'll burn it up pretty quick.

 

i dont think that hole is npt to begin with. i think its straight thread

 

I'm pretty sure it is, but I'll check the other cases I have.

Yes, and the bushing I'm talking about is the type of reducer/adapter/bushing you would use if you were trying to put a 1/8" NPT fitting in a 1/2" NPT hole in a cylinder head, or in this case, a 1/4" NPT in a 3/8" NPT hole in a transmission case. (3/8" after I drilled it out, right now, it's the factory size).

Yes, I know, but does it have to bottom out in there? or can it just go most or half of the way in there?



Guys, I know I have to use that fitting, that's not what I'm asking. I'm trying to figure out how to fixed the stripped hole it goes in. If this was in a cylinder head, I'd just drill the hole bigger, NPT tap it for the next size up, and use a reducer/bushing to get to the size I need for the fitting. Can I do that here? Or will the transmission burn up if the nipple isn't bottomed out all the way?

Thanks for all the replies so far, I appreciate it.

 

Sonnax even makes a cooler line kit for Chrysler transmissions. anyone know of something similar for other types?

http://www.sonnax.com/parts/1816-cooler-line-repair-kit

 

It's a straight pipe thread, so it would be NPS not NPT.

 

looks like you're right. thanks!

I was looking at that since TrendSetter mentioned it earlier. I'll look for a helicoil kit for that size. since the coils are steel and the case is aluminum, will that cause issues down the road? dissimilar metallurgy and all that?

 

No, helicoils are stainless steel.