RBodeman

I could not even imagine plastic blocks behind the dash making this clunking sound. It sure is not a plastic clunk that is for sure. But I would be interested in hearing about this. Anything to fix this would be great.

I think I read some place that the 5spd transmission in the HHR SS was provided by Saab. Not a great place to get a transmission being that Saab has since gone under. Way to go Goverment Motors...oh I mean General Motors.

87silver

Or that the electric power steering motor that they won't recall was sourced from Denso, subsidiary of Toyota, who rarely steps up to the plate to take accountability for anything until somebody gets hurt or worse.

cgbaroudi

Hi everyone,

Please read the following carefully then let us argue about this as long as you want to.

1. The clunk noise you hear after you switch gears and engage at the new speed is 100% normal. Your dealer is right. It is not crappy chevy/saab/swedish design or quality. Nothing is broken.

2. High performance transmission/clutch all act the same way i.e. Ferraris, Porsche's etc.

3. After some time, I now drive my manual HHR SS without hearing any clunk, whether I'm slowly accelerating or driving competitively.

I have posted a similar response to this 2 years ago on this very same site. The reason why you hear the clunk is because the speed of the engine is drastically different then the speed of the car's transaxle for the new gear you are engaging.

Depending on your style of driving, you will hear the clunk while switching from 1st-2nd or from 2nd to 3rd but not always for 3rd to 4th or 4th to 5th. Why? Because at higher speeds the engine is at lower RPM relative to the transaxle speed, therefore the speeds are somewhat similar. You release the clutch and there is no clunk.

How to avoid the clunk:

This may require you to learn a new method of driving manual.

a. You take off on 1st gear

b. when its time to switch gears, release the clutch and change gears as usual.

c. now the trick is releasing the clutch to continue at 2nd gear
-while releasing the clutch do not wait for it to engage, instead start slowly pushing the gas pedal. This allows the speed of input shaft to match the speed of the engine at 2nd gear. Make sure the engine starts spinning again before or while you start re-engaging the cluth.
- the trick is figuring out where exactly does the clutch grip and when the speed has to be more or less matching with the input shaft. You will learn with experience.

d. the result: you will not hear a clunk.

e. The first time you try to do this you may rev your engine too high or not high enough. With time you will learn how much gas is needed. The clunk sound will tell you whether or not you are synchronized.

f. Repeat the same process for 2nd to 3rd.

g. For 4th and 5th gears you will notice that the manual synchronization you are having to perform is not so necessary at higher gears since the engine is at lower RPM at higher speeds.

h. When downshifting, the same rules apply otherwise you will hear the clunk at any gear you are shifting to, including 4th. When downshifting from 5th to 4th remember your engine will spin faster therefore you must rev the engine up before you engage 4th. Don't be surprised to hear the clunk at speeds of 80 mph or higher.

i. How long does it take to get used to this new method of shifting? It took me about 3 months and today I sometimes do cause the clunk. It drives me crazy just like most of you, but at least I know what I did wrong.

j. Is there anyway to minimize the clunk without having to manually synchronize? Possibly if you switch from 1st to 2nd very quickly, leaving less time for the engine to wind down. Of course for shifting down you still have to rev up.

k. Why is my HHR SS like this? Why can't it be like my Honda stick shift? :-)
This is because your HHR SS is a high performance racing inspired vehicle. For explanation please read the provided Wiki link. I have included below an important paragraph from the article which pertains to this topic:

http://en.wikipedia.org/wiki/Manual_transmission

"Even though automobile and light truck transmissions are now almost universally synchronized, transmissions for heavy trucks <http://en.wikipedia.org/wiki/Truck> and machinery, motorcycles, and for dedicated racing <http://en.wikipedia.org/wiki/Automobile_racing> are usually not. Non-synchronized transmission <http://en.wikipedia.org/wiki/Non-synchronous_transmission> designs are used for several reasons. The friction material, such as brass <http://en.wikipedia.org/wiki/Brass> , in synchronizers is more prone to wear and breakage than gears, which are forged steel, and the simplicity of the mechanism improves reliability and reduces cost. In addition, the process of shifting a synchromesh transmission is slower than that of shifting a non-synchromesh transmission. For racing of production-based transmissions, sometimes half the teeth (or dogs <http://en.wikipedia.org/wiki/Dog_(engineering)> ) on the synchros are removed to speed the shifting process, at the expense of greater wear."

Regards,
Chris

cgbaroudi

Why are you on this forum if your car is Government Motors? I am so sick and tired of this comment. The fact that the transmission is Swedish made is on the car sheet when you buy it. It is no secret. SAAB did not go under because they made bad transmissions.