I have a 1995 Z28 with the 6 speed manual tranny, 350 etc....all stock. When im doing anywhere from 70-80mph, my car will suddenly act like its bogging down, loses power, and starts to rattle, from the back of the car. When I floor the pedal, it will eventually stop bogging and start accelerating after 4 seconds or so. It only does it in 6th gear, unless ive been driving alot that day then it sometimes does it in every gear. Lastly, when I idle in 1st gear (through a parking lot etc...) it makes a loud "pop pop pop" sound, around what i think is the transmission. Does anyone know what this is or how to fix it? Thanks

 

Hard to understand how a u-joint of a faulty T56 would suddenly, and intermittently cause the engine to bog. Why are you trying to accelerate in 6th gear..... its a 0.50:1 overdrive and only useful for cruising.

It does sound like you may have a few teeth missing off the ring gear though.

 

Well thats the thing, when it starts to bog a little bit I'm not accelerating when it does, I'm just cruising at 75. I have to floor it to make the tranny kick in it seems. I don't think its the engine, it feels like the transmission cant keep up with the engine, just because it doesn't feel like its lost power, just feels a little off

 

But how can a manual trans slip?????

Maybe your clutch is shot. Do the RPM drop with the MPH, or does the engine stay at high RPM while the car slows down?

 

The way it works is, if I'm in a gear, say 4th at 2k rpm (I have 3.23, so that is about 40 mph) and I get on the gas, the tachometer will go right to around 4k rpm, but the car will sort of bog, and after 3 or 4 seconds start gaining speed. So it's almost like the engine is telling the tranny what to do, but the tranny just is very slow to respond to the engines command. But to answer your question, the RPM does NOT go down when the car starts to shake, which leads me to my hypothesis on the whole thing that the transmission is getting orders from the engine, but the power is getting lost somewhere in the translation.

 

You sir, are in need of a new clutch.

 

Well that sucks if it's the transmission, looks like i'm gettin under it. Any suggestions on clutches that arent crazy priced?

 

IT'S NOT THE TRANSMISSION.

IT'S THE CLUTCH.

They are two separate parts.

A manual tranny can't slip "all of a sudden". Its a series of interconnected gears, not like an automatic trans with fluid couplings, friction bands, etc.

 

Yea just put transmission there on accident, was thinking to myself id have to drop the transmission to fix it. My Grand National is automatic, so never really had to deal with clutch before. Thanks for the help.