Trying to help a coworker.

[mudmobeeler]

I have not looked at this truck to try to figure it out, just talking with a coworker through texts and phone calls. He has a 98 Chevy with a vortec 305, has a non stock tune in the computer, headers and exhaust, and NOS (why I don't really know, he is a young kid and the truck isn't really anything) other than that stuff and a mild shift kit installed in tranny, nothing else is done performance wise. A couple of months ago he had an issue where the truck felt like the brakes were still applied after leaving a stop sign or stop light. According to him it was also giving other problems associated with a balloning torque convertor according to his diagnosis from the internet. He didnt take the truck in to a tranny shop or anything. So he bought an aftermarket torque convertor that had a higher stall, cant rem what for sure. Said he thought it fixed the problem but now its back and he also is thinking back that the TC didnt really fix the problem but helped it or masked it more. Now he says it shifts extremely hard also after leaving the stop with it feeling like the brakes are still applied. He says it still feels the same in neutral as far as the brakes go and in neutral if he revs it up his rpms r slow to go up. Obviously in neutral he doesn't get the hard shift.

I had a 97 do the same thing as far as the brakes go and it ended up being the booster was faulty. I never tried mine in neutral or anything though so the symptoms still occurring in neutral and the slow revving as far as the rpms go kinda stumps me. Being that everything other than the hard shift occurring in neutral it leads me to believe that it isn't anything with the tranny. But I have been wrong before so I wanted to run it by you all.

Thanks in advance.

 

[ryoken]

ya need to start isolating the issues as you've alluded to about the trans.. first, if it feels like the brake are doing that, you need to rule them out as an issue.. jack each end of the truck up and see how they freewheel, work, etc.. than move on to the next possible culprit...

 

[mudmobeeler]

He says its not the brakes, just described it as if it is the brakes. He thought he had a dragging brake but had it up on the lift and all brakes are releasing, none dragging.

 

[ryoken]

try unbolting the converter and see if the slow revving goes away.. it sounds like a trans issue to me...

 

[diesel4me]

I've heard about a tranny someone had (Th-400) that cracked the case internally and the passages that had the crack allowed some pressue to cross-feed and be applied to clutches that shouldn't be applied in forward gears (like a trans-brake?) and the owner said it always felt like the brakes were dragging or it had a tire almost flat kind of feeling....it lasted a year before he got disguted enough to pull it back out ,and bring it to a tranny shop--they said evidently the case where the valve body bolted up either had a crack and it went un-noticed,or it cracked shortly after the first rebuild it had in another state the previous owner had done--said all the "guts" were installed correctly,but the forward clutches showed signs of being overheated....

 

[mudmobeeler]

Yeah I told him to unbolt TC and slide it back enough to start it. Haven't heard back from him yet.

 

[Bowtie85]

That sounds like my old blazer, started shifting hard. Next thing I no it wouldnt shift into drive. had to manually shift it, and it was dragging pretty hard. About 10k later it pretty well locked up. I ended up getting rid of it, my buddy just swapped the trans out. So I dont know what really ended up going in it

 

[diesel4me]

I've heard of the stator in the torque converter failing and can cause it to act like its "dragging",it'll feel like its taking off in second gear ,even in first gear--once its up to speed (35 mph or so) it will seem "normal"...when the stator doesn't work right you lose the torque multiplication it provides and you'll notice the engine refuses to accelerate like it should on take offs..