Thread: Noise after losing 4th

Lost 4th gear today, but not sure what this noise is. Any thoughts?

03 Grand Prix No 4th Gear Noise - YouTube

Likely that call that.. crap from the 4th splines on the filter restricting flow.

Go get it Tiger
http://www.grandprixforums.net/how-t...ess-54448.html

I'm interested to know the result of this issue. Any updates?

Eh after about a week it stopped making that weird noise.

4th hub is being replaced on the 20th so I can give you more updates then.

my last truck i had the dealer rebuild the tranny, and it was whining just like that 2 days later. mind you this was the second attempt at rebuilding my tranny and i only brought it in for because i could make it slip in reverse only, ever so slightly.


cut the filter open, im dying to see whats in it.

ha i'm gonna ask to keep the filter and the hub.. and my guess is i sheered every spline off that hoe. it's probably a smooth hub. there was no slipping in 4th or any signs of it going. just gone.

Oh you're taking it somewhere? I'm going to attempt it on my own soon. I have 4th though, as of now. My old pcs will sit on my shelf of failed parts from my car, lol. And the 4th gear hub will too, just as a "was going to fail" part.

btw what mileage were you at when you lost fourth? I'm interested in at what point they often fail.

well what burns me up is the fact is an 03 model, and 03's had hardened 4ths. but I'm guessing mine was too early in production before they changed.

i was at 140k miles when it went. i don't think it would have broke if it wasn't for the 4-2 downshifts. i was cruisin in 4th, passed a car, never went back into 4th lol

Well maybe that was the "last straw" but by no means should flooring it on the freeway have to = 4th gear death. But that's how it is when they get weak. After the new one is in you should feel free to use 4th as you please like a normal car lol.
That's why I want to change mine while I'm there changing my pcs. So I can stop worrying about not giving it too much gas in 4th. I keep thinking, now I hope I'm not going to see my rpm's jump up and not go back down after giving it some gas. Driving will be a bit more fun once I don't have that on my mind.

i didn't even floor it. it's just the 4-2 skip shifts are hard on it. after time i suppose it'll break. but with the hardened one i won't worry so much.

Oh yeah, you'll be fine after the new one is in. Have you just been driving it without overdrive?

hell yeah lol its my only car.

cruisin at 3k+ rpm like a bauce

Originally Posted by brandonl2000

hell yeah lol its my only car.

cruisin at 3k+ rpm like a bauce

lol. I did that once not realizing right away I had the selector in 3. I could hear the engine revving higher than it should at 70 mph, horrible for fuel economy I'm sure.

got that right

What is bad on the hub is the stuffing it to the floor in 4th. All that torque hits the hub before the downshift to third. I had my bonnie trans rebuilt at 188K and still had 4th. However.. that hub was mighty close to telling me to kiss it's butt.

Got an impala in the garage and a trans on the floor. Yawn.. off to the other house.

Yeah that's what I was thinking. That's why when I'm on the freeway I'm always careful on how much gas I give it. It shouldn't have to be that way though. I just want to replace mine and stop worrying about it.
It's the same when people go past like 120 mph and go into 4th gear while still flooring it. That's a way to kill it if it's worn.

Edit: then again back when I first got my car it entered max adapt, and slammed into 4th gear. If it didn't break then, I'll bet it's still a ways away.

me being 05 impala do i still have to worry about 4-2 shifts?

From Triple Edge Performance:
"Again a common problem with this transmission until GM made an upgrade in later models. There is a clutch hub inside this trans for 4th gear and has a long hollow shaft with splines on one end, and lugs on the other end for 4th clutches to key into. The splines on the small end will turn razor sharp over time and eventually wear off. Constant in and out of 4th gear and lockup in 4th gear puts stress on the splines with constant hammering back and forth from driveline load change puts a lot of stress on the splines which eventually leads to failure and no 4th gear. Later GM parts as well as the aftermarket both offer a 4th clutch hub with heat treated splines which eliminates the problem. Most* all 2003 and newer vehicles came from the factory with the heat treated version. Unfortunately the transmission has to be taken half way apart to to get to this and is quite a chore to do in the vehicle though it can be done. Below is a picture of an early non heat treated shaft with stripped splines next to a newer shaft with heat treated splines. To date I have not seen a heat treated 4th clutch hub/shaft fail"


So yeah, you should be fine. It's probably one of those mid 03 changes where some 03's do, and some don't

I saw a couple of 03 Bonnies (both 10/02 or 11/02 builds) with non hardened shafts. GM used up what they had and then changed. Question on an 03 is... which part did it get?

I think mine was 10/02 as well..