Problems With Downshifting Into Second

[Dawizman]

I bought my '96 firebird at the beginning of december, and never noticed this problem on the test drive because I never downshifted into second to decelerate.

Anyways, here is my problem:

When ever I downshift into second without either hitting a perfect rev-match, or over revving it, I get a horrible wheel-hop like effect going on. Like the whole rear end bounces till I put the clutch back in and rev it up befire I let it out again.

This has me worried. What do you think is wrong? Could it be the second gear syncrho? Or should I check my u-joints? Or is it just a crappy clutch (I doubt it, because its only on the d-s to second). Is it my rear end possibly?

[HokieBird]

To me it sounds like you are poping the clutch and spinning the wheels, but you are getting wheel hop instead of actually spinning them. If it is wheel hop then a set of lower control arms and letting the clutch out smoother will solve that for you.

It wouldn't be the synchro if the shifter goes into the gear smoothly without any grinding. I don't see how it would be u-joints, clutch, or the rear end either, but maybe I'm not understanding whats going on.

[shenanigans]

Iv your getting the shifter into 2nd its not the syncrhos... If you have to rev match to get it to go in it sounds like the syncrhos


it jsut sounds liek maybe you are dropping tyhe clutch and the motor isn't spining up fast enough to match the wheels and its kind of like you are draggin the wheels with the motor.

[Dawizman]

Originally posted by shenanigans:
it jsut sounds liek maybe you are dropping tyhe clutch and the motor isn't spining up fast enough to match the wheels and its kind of like you are draggin the wheels with the motor.

Yes. Thats exactly whats happening. Would this signify damaged drivetrain/suspension components, or it is simply the nature of a car like this? I'm used to driving a FWD 4-banger with a 5-sp.

[98Camaro3.8]

Originally posted by Dawizman:
</font><blockquote>quote:</font><hr />Originally posted by shenanigans:
it jsut sounds liek maybe you are dropping tyhe clutch and the motor isn't spining up fast enough to match the wheels and its kind of like you are draggin the wheels with the motor.

Yes. Thats exactly whats happening. Would this signify damaged drivetrain/suspension components, or it is simply the nature of a car like this? I'm used to driving a FWD 4-banger with a 5-sp. </font>[/QUOTE]Just let the clutch out slower?

[shenanigans]

Originally posted by 98Camaro3.8:
</font><blockquote>quote:</font><hr />Originally posted by Dawizman:
</font><blockquote>quote:</font><hr />Originally posted by shenanigans:
it jsut sounds liek maybe you are dropping tyhe clutch and the motor isn't spining up fast enough to match the wheels and its kind of like you are draggin the wheels with the motor.

Yes. Thats exactly whats happening. Would this signify damaged drivetrain/suspension components, or it is simply the nature of a car like this? I'm used to driving a FWD 4-banger with a 5-sp. </font>[/QUOTE]Just let the clutch out slower? </font>[/QUOTE]Sounds like the solution...

don't think your really supposed to that in any car, if it DIDN'T do that its possible you have a lack of compression maybe?

[Dawizman]

Well, it happens when I let the pedal out fast or slow. If My engine RPM is more than a couple hundred RPM lower than the RPM it should be going down into second gear, it'll do it. It wont do anything similar going down into any other gear or any RPM. I actually noticed today that when I upshift into second and let the rpm drop down before I let out the clutch that it has the same effect. Now it has me totally confused.

[Vracer111]

Originally posted by Dawizman:
Well, it happens when I let the pedal out fast or slow. If My engine RPM is more than a couple hundred RPM lower than the RPM it should be going down into second gear, it'll do it. It wont do anything similar going down into any other gear or any RPM. I actually noticed today that when I upshift into second and let the rpm drop down before I let out the clutch that it has the same effect. Now it has me totally confused.

Um, you just answered what your problem is... you are letting the clutch out with the engine spinning to slow for the drivetrain. I know because I've done it on track (along with needing to grab third under braking for a corner but accidentally going into second...brain fade :( )...2nd has to be near perfect timing when you are downshifting in a hurry(especially when going into second at 4000+ rpms) or the rear end will hop because you've "engaged" the driveline at too low an RPM for the actual speed the car is traveling - so the tires and rear drivetrain/suspension are jolted and hop to match the actual speed you are traveling at. It's only really noticeable in second because of the gear ratio when compared with the other gears (though first gear would be worse...) A couple hundred rpms off of where you should actually shift is a LOT! Whether you are upshifting or down shifting doesn't matter at all, shifting too far from the ideal RPM (either too high or too low) is what really matters! The solution is to match engine/drivetrain to the correct rpms when shifting (it's a lot easier on the synchros and drivetrain when you do that too!)

[ January 18, 2006, 12:19 AM: Message edited by: Vracer111 ]

[Dawizman]

Originally posted by Vracer111:
</font><blockquote>quote:</font><hr />Originally posted by Dawizman:
Well, it happens when I let the pedal out fast or slow. If My engine RPM is more than a couple hundred RPM lower than the RPM it should be going down into second gear, it'll do it. It wont do anything similar going down into any other gear or any RPM. I actually noticed today that when I upshift into second and let the rpm drop down before I let out the clutch that it has the same effect. Now it has me totally confused.

Um, you just answered what your problem is... you are letting the clutch out with the engine spinning to slow for the drivetrain. I know because I've done it on track (along with needing to grab third under braking for a corner but accidentally going into second...brain fade :( )...2nd has to be near perfect timing when you are downshifting in a hurry(especially when going into second at 4000+ rpms) or the rear end will hop because you've "engaged" the driveline at too low an RPM for the actual speed the car is traveling - so the tires and rear drivetrain/suspension are jolted and hop to match the actual speed you are traveling at. It's only really noticeable in second because of the gear ratio when compared with the other gears (though first gear would be worse...) A couple hundred rpms off of where you should actually shift is a LOT! Whether you are upshifting or down shifting doesn't matter at all, shifting too far from the ideal RPM (either too high or too low) is what really matters! The solution is to match engine/drivetrain to the correct rpms when shifting (it's a lot easier on the synchros and drivetrain when you do that too!) </font>[/QUOTE]Well, I guess I learned something today. I learned to drive stick in a 1996 ford escort, and it never had that issue.

[98Camaro3.8]

If you let the clutch out slow, it shouldn't do it. By releasing it slowly you're giving it time to slip, which brings the engine up to the correct speed gradually...rather than just dropping the clutch which puts a huge shock on everything.

You can be cruising in 3rd gear and downshift smoothly into 2nd without using the throttle, just by releasing the clutch slowly. It's not great for the clutch, but it shouldn't be jumpy.