4 Reverse gears and 1 Forward (S2, 336 Trans)

[bozman]

I don't want to sound silly, but how did you determine that the transmission was in reverse?  Did you actually run the engine?  Also, what engine is it?
I cannot figure out in my mind how the transmission could be assembled with 4 reverse and one forward.

I was not there mind you, but I am being told that the engine was started (for the first time after complete restoration) while the rear wheels were off the ground.  It was put into 1st gear, and the wheels went backwards . . . and then (apparently) it was put into reverse and the wheels went forwards . . .

[jbcollier]

This was an infrequent, but not unheard of, outcome with air-cooled VW transaxle overhauls.  You just put the ring gear on the wrong side.  Or, you fit a bus transaxle into a Beetle.  It shouldn’t be possible with a Renault transaxle though.  Interested to hear what you find when you open it up.

[bozman]

Indeed, we have discovered that the ring gear has been installed on the passenger side and should be on the driver side . . .

[Pfreen]

I never imagined a hypoid gear could be installed backwards.

Congrats on "the find"

[jbcollier]

Before you take it further apart, please run a pattern check with bluing so we know how well the teeth were meshing.

[dakazman]

   Interesting, If the gears are meshing correctly now , maybe that all we need to do on a renault gearboxes to get out of the four reverse ,one forward .    It also would open up more donors.
 dakazman

[Grumblebuns]

I'm a bit confused here, not the first time. If the R16 336s can't have the ring gear flipped over, per an earlier discussion, how can the Lotus 336 be able to have it's ring gear flipped over? Supposedly, only the ring gear and pinion gear are different between the two transaxles with everything else remaining the same.

As an FYI, while taking a Manual Transmission class at my community college, I tried to flip the ring gear over to the other side as an experiment. At that time it did not look possible since no matter what I did, I could not get the pinion gear to mesh with the ring gear. Perhaps I didn't try hard enough. I really would like to see what your shop did to make this possible.

[bozman]

I would argue that the ring gear can be flipped over, because that is exactly what we did (incorrectly) the first time.  I am asking if the meshing was properly checked the first time around, but I can confirm that there is space for ring gear and differential to be swapped to either side. 

[jbcollier]

Always known there was the room but the gears are not supposed to mesh properly if the ring gear is flipped.  Absolutely you can shove them together and get the "correct" freeplay but you shouldn't get a proper mesh.

[bozman]

She is home with me now.  I am sure they didn't check the meshing initially, which has me concerned about what other corners were cut.

Anyway, it's now my turn to make this right.  Thanks for all the input!

[shootingsight]

It's not really the 'transmission' that has 4 reverse and 1 forward, it is the 'differential' that has the ring gear flipped, so the engine and transmission are spinning correctly, but the diff makes the wheels go backwards.  Of course, in this case, the transmission and differential are integrated, but conceptually they provide separate functions.

Interested to hear how this resolves, because I had always heard they just flipped the ring gear.  Of course this was casual talk, I never had anyone with Collier's level of knowledge to point out this was not possible with a slight helical cut.

[jbcollier]

Here's a '67 article on the Europa in Renault UK's own in-house publication:

http://lotus-europa.com/literature/Autoworld-Jan-Feb-1967.pdf

Regarding the gearbox it says:

"The gearbox retains the standard ratios of the 16 saloon, but new final drive gears, cut to rotate the other way when installed 'backwards' in the Lotus, give a slightly higher drive ratio of 3.56 instead of 3.77 to 1.