700 R4 help?

[evilklown4u]

1991 3/4 ton chevy with a "new rebuilt" upgraded to everything turbo tranny. Getting onto freeway at on ramp, everything going fine a "bang" sound, tranny instantly started to fail, truck pulled the grade with NO POWER, coasted off of the freeway. You can feel hook up in each gear but tranny will not pull? Any ideas? Does this sound like a converter? local shop says that is what it is? Any help would be appreciated. Thank You.

 

[PenguinLTZ]

This must be one of those light duty 2500s with the 6 bolt wheels??
If it is slipping at all, it's over.

 

[evilklown4u]

I guess you didn't notice it said 3/4 ton? I've never seen a 3/4 ton with 6 lugs! Thanks for your input!

 

[66nova]

I guess you didn't notice it said 3/4 ton? I've never seen a 3/4 ton with 6 lugs! Thanks for your input!

I don't want to put words in Scott's mouth, but I'm guessing he is basing his response based off of the 700r4 part.

A 91 3/4 ton should have the 4L80E unless it was an early production and it could possibly have a TH400. The 4L80 is basically a 4 speed version of the TH400.

Regardless, he's correct. If it's slipping, it's toast. Could possibly be very low on fluid, but if that's the case where did it go?

 

[PenguinLTZ]

I guess you didn't notice it said 3/4 ton? I've never seen a 3/4 ton with 6 lugs! Thanks for your input!

Yes I saw it.

Yes they had light 2500s in 91 with 6 lugs

Regular 2500s did not come with 700R4s

I really was trying to help.

Welcome to the site

 

[Black02Silverado]

It could be the TC. How does your fluid look? Just for it to completely fail means something let loose, especially if you don't have any reverse as well.