Gear selection rebuilding T56
12-11-2010, 10:14 PM
#1
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Gear selection rebuilding T56 Ive seen a broad array of gear sets available for T56s, mostly ranging from 2.97-2.66 1st gears and .67-.50 6ths. Ive seen 1st gears advertised as low as 3.36. My question is if a t56 is being rebuilt can new gear ratios be used to get the widest gear spread? Could you take a trans that was normally a 2.97-.62 spread and change first to 3.36 and 6th to .5?
12-11-2010, 10:24 PM
#2
No. A 3.36 first / .62 sixth (used in 2.73 rear 1993 F-bodies can't be geared to have a .50 sixth without custom gears being made.
The 2.97 first / .56 sixth is a really good (steady % drop from 1-2, 2-3, 3-4) ratio set if you like a wider set than the 2.66 first boxes. I always liked the 2.9x first gear T5s I previously had.
If you sit down with the different speed gear tooth counts and countershaft tooth counts and do the math (read: make a spreadsheet), it's obvious how they got the 2.97 first / .56 set from basically existing parts back in the 90s when previously there were only the 3.36 / .62, 2.97 / .62 and 2.66 / .50 in production.
If you have a heavier vehicle, the SSR has a nominally higher 3.0x first gear but the already-existing boxes out there are really good already.
The 2.97 first / .56 sixth is a really good (steady % drop from 1-2, 2-3, 3-4) ratio set if you like a wider set than the 2.66 first boxes. I always liked the 2.9x first gear T5s I previously had.
If you sit down with the different speed gear tooth counts and countershaft tooth counts and do the math (read: make a spreadsheet), it's obvious how they got the 2.97 first / .56 set from basically existing parts back in the 90s when previously there were only the 3.36 / .62, 2.97 / .62 and 2.66 / .50 in production.
If you have a heavier vehicle, the SSR has a nominally higher 3.0x first gear but the already-existing boxes out there are really good already.
12-12-2010, 09:41 AM
#3
If you sit down with the different speed gear tooth counts and countershaft tooth counts and do the math (read: make a spreadsheet), it's obvious how they got the 2.97 first / .56 set from basically existing parts back in the 90s when previously there were only the 3.36 / .62, 2.97 / .62 and 2.66 / .50 in production.
I highlighted most of the math and tooth-counts for the T56 in the Appendix of the 32-spline conversion:
http://www.eecis.udel.edu/~davis/z28..._Fbody_T56.pdf
