VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Highway gears for 30 Chev.

I'm considering installing a set of highway years in my 30 Chev.
When I drive the car around town I generally leave the car in 3rd gear whenever I can make a turn at an intersection where I don't have to stop since I haven't mastered the art of down shifting these square cut gears without a lot of grinding. With the 3.50:1 gears in the Diff. my guess is that I would have to start gearing down when making turns on the fly.
Just finished ground up restoring on this 30 Coach two years ago. I would like to get the extra 10mph out of her but not at the expense of trashing the transmission.
I'm currently using SAE80W-90 gear oil in the gearbox.
Sure would like to hear from anyone who has installed the highway gears and any advise you can offer concerning installing and operating the car with the highway gear set installed.
Maybe I just need more practice downshifting from 3rd to 2nd gear!

Hi There and Welcome to Chevy Chatter II. Glad to have you with us.

Regarding the highway gears from Larry Jackson, there have been many discussions on this subject in the past. You might want to do a search on Chevy Chatter II to bring up all of the past discussions regarding the 3.50 gear set.

I installed the highway gears almost ten years ago. It's made driving a lot more fun. However, they will not make downshifting easier. The gears make driving at 30 plus mph a lot smoother. For me it was well worth the cost and effort.

I put my first set in my '31 in 1986. I've never regretted it since then. I had a '31 Coupe for a while with 4:11 gears and it was somewhat annoying. Sure is nice to go all the way across the intersection before having to shift to second gear.

Downshifting with the square-cut gears does require a little learning curve, but once mastered, it's "the only way to drive"!! ha ha.

Thanks Karl
I will give this some further consideration.

Cheers,
Dave

Thanks Bill,
I know what you mean about getting across the intersection.
Most drivers be hind me probably wondering what's taking me so long. Maybe the gear set is worth it just for the get-up and go.

Cheers,
Dave

A major part of your problem in downshifting is the 85W-90 lubricant. It is too "thin" for that transmission. Put 140 or better yet 160 (aka 600W). Shifting will be much smoother and grinding less. Just remember to hesitate with the shift lever between gears to allow the gears to get to the same speed. That includes both up and down shifting.

The problem is not the square cut gears. The transmission does not have syncronizers and it is necessary to double clutch when going from gear to gear.
It is necessary to depress the clutch, then place lever in neutral, quickly release the clutch and depress it again and move lever to next gear. Sounds kind of draged out but can be done in less than a second.
You can also try to matach the engine speed to what it will be in the next gear.
The early 1932 has square cut gears and a syncronizer and could easily be down shifted (when the syncronizers were working correctly)

Do a Google search on term "Double Clutching" still used today by truckers. Al W.

Thanks fellows for your comments and advice. I will go ahead and up the oil viscosity in the transmission and with a little more finesse on my part down shifting it sounds like these old cars become a little more road worthy with these highway gears. I have put my request in with Larry Jackson.

Happy New Year!
Cheers,
Dave

You won't be disappointed with the highway gears or dealing with Larry.