Clunk (hard shift?) when accelerating up a steep hill? Other noises too.

[Mean_Green]

I live on the crest of a hill on a rural country road. Speed limit is 35, but I never get close to that knowing I'll need to stop to turn into my driveway. While the hill is steep, it isn't very long, maybe a few hundred feet at most. When I start up the steeper side of the hill, I may have to push down on the gas pedal a bit more to maintain constant speed of around 15-20 MPH. At some point while climbing, it shifts and there is a some kind of clunk. I can't tell if it's a hard shift or not.

There are some other noises at various times that I can't really identify. Almost seems the sound a heat shield might make if loose ... a metallic type rattling.

Sometimes when staring out from a dead stop (traffic light, stop sign), I'll hear/feel something too, but that seems like a U-Joint or similar.

I'm not mechanical enough to express these better, or to get under it and do much testing/checking. Just wondering fi I need to have it looked into deeper that the simple inspection done a couple of weeks ago where there was no road test done.

 

[Doubeleive]

I live on the crest of a hill on a rural country road. Speed limit is 35, but I never get close to that knowing I'll need to stop to turn into my driveway. While the hill is steep, it isn't very long, maybe a few hundred feet at most. When I start up the steeper side of the hill, I may have to push down on the gas pedal a bit more to maintain constant speed of around 15-20 MPH. At some point while climbing, it shifts and there is a some kind of clunk. I can't tell if it's a hard shift or not.

There are some other noises at various times that I can't really identify. Almost seems the sound a heat shield might make if loose ... a metallic type rattling.

Sometimes when staring out from a dead stop (traffic light, stop sign), I'll hear/feel something too, but that seems like a U-Joint or similar.

I'm not mechanical enough to express these better, or to get under it and do much testing/checking. Just wondering fi I need to have it looked into deeper that the simple inspection done a couple of weeks ago where there was no road test done.

is this vehicle new to you? or are these noises and such something that has just cropped up since you have owned it?

 

[Mean_Green]

is this vehicle new to you?

Ummm, yeah. About a month.

 

[Doubeleive]

Ummm, yeah. About a month.

well it is probably a good idea to have it checked just to be sure but sometimes a hard shift is not a bad thing it's just how it is, particularly on the older ones.

 

[89Suburban]

Spider gears in the rear could be getting sloppy.

 

[NickTransmissions]

I live on the crest of a hill on a rural country road. Speed limit is 35, but I never get close to that knowing I'll need to stop to turn into my driveway. While the hill is steep, it isn't very long, maybe a few hundred feet at most. When I start up the steeper side of the hill, I may have to push down on the gas pedal a bit more to maintain constant speed of around 15-20 MPH. At some point while climbing, it shifts and there is a some kind of clunk. I can't tell if it's a hard shift or not.

There are some other noises at various times that I can't really identify. Almost seems the sound a heat shield might make if loose ... a metallic type rattling.

Sometimes when staring out from a dead stop (traffic light, stop sign), I'll hear/feel something too, but that seems like a U-Joint or similar.

I'm not mechanical enough to express these better, or to get under it and do much testing/checking. Just wondering fi I need to have it looked into deeper that the simple inspection done a couple of weeks ago where there was no road test done.

Sounds like a harsh, late 1-2 shift. Could be a couple things:

1). Valve body/TCC regulator valve/bore wearing

2). Broken 1-2 accumulator springs

A light “clunk” from 1-2 or from 3-2 is normal, especially if a shift kit and “corvette” second gear apply servo piston has been installed

This assumes its the transmission and not something else.

Metallic rattling is likely a heat shield, esp if its coming from around the transmission area (trans heat shield). Check to make sure the 10mm bolts holding it on arent loose.

 

[Eman85]

Yes it should be checked out, it's a 25yo vehicle.

 

[east302]

For drivetrain, there was a TSB issued to “address” complaints of slip yoke clunk. It kind of sounds like one of the things that you mentioned when you’re starting from a stop sign.

It was a fairly common complaint when these were new.

Here’s the link:

https://ww2-secure.justanswer.com/uploads/heavychevy396/2010-01-02_122225_Slip_Yoke.pdf