Missing a gear shift - ZR-1 Net Registry Forums

32valvZ · 10-02-2020

Quote:

Originally Posted by Norwegianmopar

"If the revs were right"...I guess I was in the 6-7000 rpm range (as usual). I have driven it hard and a lot and never missed a gear before, so that's why I ask if it's bad or not.

I love "using and abusing" it as it's an awesome sports car with an amazing power band.Attachment 13100

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6-7k I would say is worse than if you were just driving the car around town casually.. Is it popping out of gear on deceleration? Is it grinding under normal driving condition... if not, youre probably ok.... for now. Keep doing it though and youll need a rebuild...

Norwegianmopar · 10-02-2020

Quote:

Originally Posted by 32valvZ

6-7k I would say is worse than if you were just driving the car around town casually.. Is it popping out of gear on deceleration? Is it grinding under normal driving condition... if not, youre probably ok.... for now. Keep doing it though and youll need a rebuild...

It happened just once, I was full throttle going from 1st to 2nd and my foot slipped off the clutch pedal and I missed second gear, hence the grinding sound. It was all fine afterwards, no problem shifting in any gear.

I just wonder how much wear and tear this grinding may cause...

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32valvZ · 10-02-2020

Here is a video of whats happening when you shift gears. The whole idea of a synchro assembly is to match the speed of the gear shaft with the teeth on the gear itself. So when you "miss a gear", what actually is happening is the shaft and the gears are spinning at different speeds and dont mesh when they should. That causes the grinding sound and since the blocker rings are generally made of brass, they will wear out the fastest. The teeth wear out as well as the cone portion of the blocker ring. I have not opened up a ZF, but many Borg Warners when I was wrenching for a living. We used to rebuild them in house when I worked for Anheuser Busch many years back. The principle is the same.

https://www.youtube.com/watch?v=0Bqs-oHBBQk

tccrab · 10-02-2020

The ZF6 is a very stout transmission, but there are limitations.
Speed shifting won't hurt it a lick.
Missing a gear while speed shifting, we'll not so much.
The 2nd and 3rd gear synchros are fairly delicate.
You will know if they need attention.

'Crabs

10-02-2020	#3
32valvZ Join Date: Nov 2007 Location: Sunshine State Posts: 1,061	Re: Missing a gear shift Here is a video of whats happening when you shift gears. The whole idea of a synchro assembly is to match the speed of the gear shaft with the teeth on the gear itself. So when you "miss a gear", what actually is happening is the shaft and the gears are spinning at different speeds and dont mesh when they should. That causes the grinding sound and since the blocker rings are generally made of brass, they will wear out the fastest. The teeth wear out as well as the cone portion of the blocker ring. I have not opened up a ZF, but many Borg Warners when I was wrenching for a living. We used to rebuild them in house when I worked for Anheuser Busch many years back. The principle is the same. https://www.youtube.com/watch?v=0Bqs-oHBBQk

10-02-2020	#4
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,663	Re: Missing a gear shift The ZF6 is a very stout transmission, but there are limitations. Speed shifting won't hurt it a lick. Missing a gear while speed shifting, we'll not so much. The 2nd and 3rd gear synchros are fairly delicate. You will know if they need attention. 'Crabs