We bought a used '99 1500 4x4 for my son to drive. Truck has 143000 miles on it. Tranny fluid smells like http://www.dieselplace.com/forum/images/smilies/Throwup.gif and looks like http://www.dieselplace.com/forum/images/smilies/censored.gif . I don't think it has ever been changed.

Now don't laugh too hard, but here's the question. Can I expect the tranny to go out shortly after I change the fluid?http://www.dieselplace.com/forum/images/smilies/confused.gif The reason I'm asking this is because of a posssible myth (or fact?) I've heard that if you let it go significantly over the recommended change interval and then change it that the new fluid will cause the clutches/bands to fall apart, clog the filter, and essentially burn up.

Is there any truth to this????

Are you sure it is a 4L80? They only went in the 8600 GVW trucks and up. I suspect you have the 4L60. I think that if it fails after changing the fluid, it would have failed about the same time anyway.

If its working fine, dont touch it. You are asking for trouble if you mess with high mileage stuff like that that has a poor maint history. I cant explain it, but it happens. Ask any tech on this board and they will tell you the same. I can show you countless examples of it at work as well....

Eric,

Would you suggest the same regarding the Allison as well?

Thanks for the replies. I gonna leave it alone.



Gary