Quote:
Originally Posted by kent olsen
Bill Verburg
If I understand your chart the 72 915 in my car has 4th gear just short of 1:1 and 5th (0.76) just a little over, interesting. I'm putting a TREMEC 5spd in my 65 Corvette and it is 1:1 in 4th and 0.68 in 5th.
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IN '72 there were 5 different 5 speed 915s, counting the special order as 1 and 2 different 4 speed 915s
All 5spds except the S/O had 29:22 5th
There were numerous detail improvements/changes over the years
here are a few
1972 - Start of production; magnesium case; 7:31 ring and pinion; mechanical speedometer; early style clutch throw out bearing tube.
1973 - Change to input shaft seal design to address service issue flaw.
1974 - Change (final) to input shaft seal design to address service issue flaw. Transmission disassembly no longer required.
1975 - Midyear change from 7:31 to 8:31 ring and pinion
1976 - Change from mechanical to electronic speedometer.
1977 – Start of transition from magnesium to aluminum case. 915/60/61 aux spring on the trans exterior, - Change to 1st and 2nd synchros, split lock before, double lock after, asymmetrically pointed teeth for 1st, smaller syncro ring for 1st stronger guide sleeve 1 & 2
1978 - Reinforced differential side cover (addition of extra ribs), nodular cast iron p/p, cast iron clutch, rubber ctr clutch, All models 5 speed now
1984 - Reduction in diameter of input shaft bearing in differential case.* This significantly helped in the reduction of problems with bearing bore ovaling.
1984 - Addition of oil pump and cooler for 915/67 & 69(RoW), 915/69 uses 930 output flanges
1985 - Improved bearing assembly, input shafts uses cylindrical roller bearing from 930(smaller OD) this was actually introduced 12/16/83 on 915/67 from trans # 915/67 02340 w/ small(100mm) cv flanges, 915/68 02192 small(100mm) joint flanges, 915/69 10081 lrg((108mm) joint flanges, 915/70 10217 large(108mm) joint flanges,
double lock gear syncros for 1 & 2, 3-5 syncros have smoothed and round end syncros(R2.5), lsd modified graphite cast iron case w/ larger holes for fluid flow and fewer disk count, only 1 ea outer and inner (also far less effective than previous lsd versions(sometimes called a 'snow belt' lsd)
all have the large 105mm joint flange
1986 - End of production