TheSamba.com :: View topic - 388 ring and pinion vs 412 ring and pinion

Thu Jan 13, 2011 1:07 pm

I have a 4.12 with a 225/70/15, I believe its around 27in tall. With a .82 and works lovely but I do have a bit bigger motor. With my old 1914, it was a little rough from 3 rd to 4th

Fri Jan 14, 2011 1:59 pm

mark tucker wrote: my 2028 has a 4.12, my 2332 had a 388. the 2332 would blow away the 2028 badly.so size does matter !! and the 2332 had 31"x16 wide tires.and the 2028 has 28" kinda skiny 8" wide tires.witch gives it more gear.
All your example proves is your 2028 has way less power than the 2332.

Mon Aug 04, 2014 11:00 pm

Sorry if I'm beating a dead horse y'all but I'm "learning".
I am in the early stages of rebuilding my '67 bus transmission. I have heard from friends that the 388 is the way to go. I have access to a 412 too.

Background:
*Trying to keep it "close" to stock, but would like a little better 3rd and 4th gear for freeway driving.
*1600 cc (going to go with a 1641 cc)
*rear tires are 195 R15 (currently 165 R15)
*keeping reduction boxes
*single port/single carb
*not a daily driver but plan to take it camping in mtns and beach, mostly freeway driving and around town, but would like to climb a little better up the hills
*average amount of weight being carried/hauled

Please give feedback on anything you feel might help and why. Also, I would like opinions on the 388 vs. 412 "debate".
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Tue Aug 05, 2014 4:53 am

You would be making a huge mistake putting a 3.88 in a splitty Bus with a near stock engine. VW geared them correctly from the factory. I personally would not go any larger then stock gearing with your 1641. If you had a larger 2000cc + stroker engine then a 4.12 might be OK. You will have to understand that 55 MPH is the only way your engine is going to live a long life.

Tue Aug 05, 2014 5:08 am

The '66 & '67 vans originally came with 8:35K (4.37) R&P (contrary to a popular "authoritative" list) for a reason. This is a strong 8-bolt R&P (in contrast to the early 8:35G Bug 6-bolt R&P). Of course, this was still paired with a .82 4th gear (and later 1.26 reduction gears) yielding a decent highway cruising speed.

Very few early vans today have their original transaxles. Many have been replaced with bug transaxles, with flipped ring gear, 8:33G (4.12) R&P, and .89 4th gear. This combo will yield approximately the same highway cruising rpm. The R&P may not be as stout, but it's a decent replacement.

The 8:31G (3.88) R&P is the strongest of all Type I (& EARLY Type II) R&Ps .. but the resultant rpm drop of the taller ratio MAY cause engine overheating .. ESPECIALLY if paired with the .82 4th gear. There are always exceptions (and of course there's the no-reduction gear crowd). But if you have hills to deal with, you should approach the R&P change with caution. I've even done this mod myself, but resigned myself to using 3rd gear on hills where I could previously use 4th.

Wed Aug 06, 2014 1:59 am

Thanks for the info guys. Back to the drawing board for me. :roll: