Hello,
Is the final gear of an original 914-6 gearbox the same as a 914-4 trans or is it shorter because the six has its top power at a higher rpm?

Thanks in advance,
Walter

Hey Walter,

I'm no gearbox guru, nor do I play one on TV
But I think the final drive is the same.
Some of the gears are different between the /4 and the /6 though

Yep, I believe the 6 box just has different gears and the 5th is lower than the 4 box. But I believe the final drives are the same.

When I converted my six from tail shifter to side shifter, I used the 914-4 5th gear, it's a ZD or DZ gear, cause it's taller. Dropped my engine rpm at freeway speeds 400-500 rpm. Now I'm doing 3900 rpm at 80mph instead of 4400 rpm at 80mph.

So, based on that, I'd say the gearing between the two is different. Oh yeah, acceleration with the taller gear is just fine. I also get around 25 mpg at freeway speeds. With todays gas prices, every little bit helps.

The story I always heard:

the -6 had a lower fith in order to intentionally raise rpm while cruising... It might not matter so much with the 65 and 75mph speedlimits....

but the engine cooling air is directly dependant upon engine rpm.. And the story I had heard was that the stock -6 cars needed a bit more cooling air forced over the heads for constant highway cruising.....

brant

914-4 is A-F-N-V-O
914-6 is A-GA-O-V-ZA

The 914/6 gears have the same first, a much taller second , a slightly taller third, the same fourth, and a shorter fifth than the 914/4. Basically the six has a closer ratio gearset from second to fifth.

914/4 - A, F, N, V, ZD
914/6 - A, GA, O, V, ZA

Thanks guys,
I think all posts combined answer my question quite extensively
Reason is, I saw such a box for sale quite cheap, but if 5th is a shorter gear, its not for me.

regards,
Walter

Fifth gear in a 914 is easy to change, but you have to pull the gear stack from the transmission, and you have to have the socket to remove the nut on the input shaft. 5th gear is the very front one. I have done a lot of checking on this lately, and IMO, you should use 5th from the 4 cylinder cars. It wil lower the RPM at freeway speed. If you have a 4 cylinder car, and you can find one, get second from a sportomatic, and flip it. Joe Yoder did that for his 2.0, and that car cruises nice on the freeway.

Thanx, Vegas Racer for correcting me on the 914-4 5th.
It IS ZD, not O.
My tongue got in front of my eye tooth and I couldn't see what I was saying !
Thanx Vegas Racer