which in turn

[dn3805]

Hi, I have a question about the meaning of ' which in turn' in the sentence below. This text came from automotive topic about transmission gears operation.

"Reverse on mainshaft rotates reverse idler gear which in turn rotates countershaft reverse gear in the opposite direction."

I am still confused what which in turn implying to or referring to ,reverse on mainshaft or reverse idler gear ?

Thank you.

dn3805

 

[Cagey]

Hello dn3805.

Welcome to the forum.

If I knew more about automobile transmissions, this would probably be clear to me, but relying only on my understanding of English syntax, this is what I think. (I have added 'the' where the manual has left it out.)

Reverse on [the] mainshaft rotates [the] reverse idler gear
which in turn
rotates [the] countershaft reverse gear in the opposite direction

Grammatically, "which" could refer to the action "rotates the reverse idler gear'"

(=the act of rotating the reverse idler gear causes the counter-shaft reverse gear to rotate in the opposite direction)
​

Or it could refer to the noun it follows, the reverse idler gear.

(= the reverse idler gear causes the counter-shaft reverse gear to rotate in the opposite direction)
​

The second seems to me the more natural reading, but I don't see much difference between them in meaning.

In most cases, the relative which will refer to whatever is just before it. Here will not refer back to "reverse on mainshaft", though it might refer to the motion it causes, "rotates the reverse idler gear."

Someone else may interpret this differently.

 

[Beryl from Northallerton]

Hello dn3805, and Welcome to the Forum !
My interpretation is similar to Cagey's - 'which' refers to the 'reverse idler gear'; 'in turn' indicates that there is a chain of causation: rotating 'idler gear' >>> rotating 'reverse gear'.

 

[dn3805]

Thank you Cagey for your help. Now it becomes clear after I read your explaination. By the way, the source was from Honda CRV service manual.

 

[dn3805]

Thank you Beryl for your help. Now I understand and it makes sense.