ZF Question - Fact or urban legend
 

Another Corvette owner was told by a repair shop that resting your hand or forearm on the shifter while driving leads to transmission destruction.

I visited zfdoc.com and did not see that concern posted. Can resting your hand or forearm on the shifter while driving lead to destruction of the transmission? :willy:

Bob

Well....I can't tell you anything about a C4.

But, I can tell you from experience, that in a C2, it will wear the synchronizer fork and the mating groove in the synchronizer collar badly over time.
It was not uncommon for the shifter assembly to rattle on C2s. And, it wasn't uncommon for the driver to rest his arm on it to keep it quiet. And, it wasn't uncommon for that to wear the parts I mentioned above.
Twenty five years ago, I had to replace these parts in my C2 for that reason.

So, it may be an urban legend in a C4, but it is a fact in a C2.

Tom Piper

Generally speaking, it's not considered a good practice. Whether it could hurt or not or how much is probably dependent upon on the design of a particular transmission. But in some it can definitely put preload on the sliding sleeves and/or the forks that engage them (in a constanst mesh tranny) and so should be avoided as a matter of course.

Thanks for the replies, transmission in question is of course a ZF 6 Speed in an 89.

Bob

Thats a new one! (I have never heard this one):eek:
I have 2 89 6speeds and I usually keep my hand on shift knob while driving and have never had any tranny issues!

It is and it isn't bad, it all depends on the individual. The trick is to not apply any pressure on the shifter when your hand is resting there, otherwise your pushing the shifter forks against rotating parts, and this is what causes the excessive wear.

I would imagine that putting constant fore/aft pressure on the lever could wear some internals, but if the pressure in only in the vertical axis it shouldn't harm anything.

Larry
code5coupe

in all the manual cars i've driven, i've always rested my hand (not applying extra pressure though) on the shifter knob. in my vette most of the resting weight is at the elbow as it naturally rests/pivots on the center console lid anyway. i've never had any problems with transmissions.

I would imagine there is a difference between resting your arm on the shifter and actually applying a load. I don't know about you guys, but since the back of my arm rests on the arm-rest, and my hand just rests on the shifter, the actual force on the shifter is gonna me like a couple of ounces. Now if your arm weighed 700 lbs it might be a problem.

Almost all shifters, including the one the put on the ZF 6 spd, are designed to take heavey loads from the speed shifting public. If you take one of these mechanical marvels out of the car and look at them, resting your hand on the shift handle is not going to break anything or cause problems. With the shifter or the tranny.

The only shifters I have broken included the 3 spd on the column 63 ford fairlane. Had to replace the collar on the steering column. It wore out when you slamed 2nd gear and broke at the pivot. Then there are the hurst compitetion pluses that slide out of connection with a slight miss-shift and save the tranny.

I put the hurst ZF shifter in at 110,000 miles and it improved the shifting and tightened everything up. An from time to time I use the shifter to rest my hand while adjusting the radio. By the way the stock shifter worked just fine, but a little sloppy and long. Sloppy can be fixed with new shims from the top. But the hurst is more fun.

good luck. Polo