Well crap, the input shaft seal behind the torque converter started leaking on my IROC. I replaced it when I installed a new Hughes Stall Converter around 1500 miles ago and there was no signs of any leaks until now.

I have always adjusted my TV cables so that the transmission will shift into second gear at 17 MPH and have never had a pump seal go out; I wonder if maybe the line pressure was a little too high and blew out the seal? Either way, it looks like I'll be pulling the transmission next week.

 

dang, that sux.
IDK if theres really any pressure on that seal? maybe if the vent was plugged up?

 

I had a similar problem, but I think mine was just that I did a complete rebuild with a kit from Probuilt, which raised line pressure and I failed to drill out the relief hole in the pump. If all you did was a new converter, you should inspect the front pump bushing for excessive wear, check the converter shaft runout for wear marks that would show if it's off center or not. If the converter is ok, pull the transmission and take the pump out. Split the pump and enlarge the hole to 9/32. I drilled to 5/16 because I couldn't quickly get a 12" long 9/32" bit. If you are not comfortable doing this, you could take the pump to a transmission shop, they'll know what to do.


This is only the front of the pump, you have to drill the horizontal hole that meets this one. On mine, that diagonal hole was already 9/32", but the horizontal hole in the front half of the pump was 1/4" and the horizontal hole in the back of the pump was smaller than 1/4" so it was one restriction after another. Mine only leaked on full throttle runs, it's nice and dry after I drilled it to 5/16".

 

Interesting, I'll check it all again, but everything looked great when I installed the new converter; hopefully it's just one of those things and it was just my turn with the angry seal gods.

 

something about adjusting the tv cables differently than what GM intended scares the hell out of me. I'm pretty sure you're not supposed to control shift points via the tv cable.

 

I've done that for many years and to be honest, most of them shift out right at 17 mph adjusted by the book; I've never had to do more than just barely adjust it to get it to shift at 17 mph.

 

MSgt, if the seal popped out make sure to get the metal retainer for it. This was a GM upgrade that occurred someplace along the years of manufacturing these transmissions.

Here is what it looks like:

http://www.coanracing.com/Catalog.as...uctDetail=1047

Note that this link is just for ID purposes.

RBob.

 

Now this is some handy info!! I work on so many vehicles, I don't recall if mine had this retainer on it or not, I'll be picking a new one of these up.

 

Changed out the seal, reinstalled transmission and it still leaks! Since i cleaned the crap out of everything while i had it out, when it started to leak while still on the lift, I was able to see that it's not coming from the input shaft seal, but looks like it is coming from the pump housing O ring instead. Damn it! Pulling it back out next week to replace the pump housing O ring seal; lesson learned.

 

There's a paper pump gasket, pump o-ring seal, and bolt o-ring seals. None of those make sense to leak when replacing the converter. I feel your pain, I have pulled my transmission so many times that I can now have my transmission out, on the floor in about an hour now. Did you remove the pump and split the pump halves to replace the seal? If so, how did you center the pump halves during reassembly? My only thoughts are bolt seals or pump not aligned.

 

I won't have time to yank it back out until some time next week, but it's got to be the big O ring that goes around the pump housing that's leaking; the car sat up for a few years before I got it and started the build on it, so maybe the seal got dry and cracked. I'll update this when I have more info.

 

aww man, sorry to hear that. i'd be pulling my hair out.
if it makes you feel any better, i broke 2 pumps, an input shaft and a converter last year. uhhggg.

 

Well, we pulled it out and and pulled the pump, all the seals were fine, but the case is cracked; it didn't take long for the stock 700r4 transmission to **** to bed behind the new 383. Not sure if the transmission was already on its way out before the engine swap or not, but it's history now. I pulled the trigger on a new Level 3 Hi Performance 700r4 rated to handle 600 horse power and a new 2600 rpm stall converter. Like they say, that's hot rodding.................

https://transmissioncenter.net/produ...700r4/level-3/

 

The new Raptor 700 transmission installed and all I can say is holy cow, I had no idea how bad off the other transmission was. *This thing is a beast with the new transmission and the best way to describe the acceleration now is violent; the transmission shifts out at 5500 RPMs when the car is floored and zero to 100 MPH is damned impressive.