Quote:
Originally Posted by MUSLCAH
W hat gear ratio came with 1964 GTO Tri power with Automatic trans ? Thanks
|
PMD announced a revision for the standard Axle Ratio for the '64 Tripower GTO, the change was effective with production starting January 27, 1964 at which point the 3.23 axle ratio became standard.
That doesn't tell the whole story. The Tempest Axle Charts were fairly complicated since the standard axle ratio could be affected by several option selections.
But since you only asked about the Tripower GTO with Auto Trans, I will focus on that application.
From January 27 on, the 3.23 axle was the standard release with standard brakes except when the auto trans Tripower GTO was optioned with A/C but NOT with either of the two Trailering options.
For such a build, the standard release (from Jan 27) was the 3.08 axle with standard brakes.
To be clear, the Tripower GTO with Auto Trans (from Jan 27) when optioned with EITHER of the two Trailering options WITH or WITHOUT A/C, got the 3.23 axle with standard brakes as the standard release.
For each of these combinations, you could special order the 3.08 axle with standard brakes. Since the 3.08 was standard for the A/C WITHOUT either Trailering option, obviously you couldn't special order in that case.
You could special order the 3.36 axle with standard brakes for all combinations but NOT with A/C.
And you could also special order the 3.55 axle with standard brakes for any of these combinations except you could NOT order the 3.55 with A/C.
Although the 3.90 axle with standard brakes was produced you could NOT order it for any GTO.
The combinations with Metallic brakes were the same but with one exception since you could not get the 3.08 axle with Metallic brakes.
The 3.23 axle with Metallic brakes was the standard release from Jan 27 for the Tripower GTO with Auto Trans WITH or WITHOUT both Trailering options and WITHOUT A/C.
The 3.23 axle with Metallic brakes was the standard release from Jan 27 for the Tripower GTO with Auto Trans WITH either Trailering options and WITH A/C.
According to the Axle Chart, you could NOT order Metallic Brakes with A/C UNLESS you also ordered one of the two Trailering options. This would seem to have been due to the fact PMD didn't produce a 3.08 axle with Metallic brakes.
Same as for the standard brake special order axles, you could specify the 3.36, 3.55, or 3.90 axle for any Tripower GTO with Auto Trans except you could not specify any of these choices with A/C.
PMD claimed the change to the 3.23 axle in '64 for the Tripower was "to further satisfy performance and fuel economy requirements".
This never made sense to me. The 3.55 was largely satisfying the performance desires of Tripower GTO buyers and quite a few were specifying the 3.90 axle.
But this is what PMD announced, make of it what you will.
Prior to January 27, the 3.55 axle was the standard release with standard brakes except when the auto trans Tripower GTO was optioned with A/C but NOT with either of the two Trailering options.
For such a build, the standard release (prior to Jan 27) was the 3.08 axle with standard brakes. Note, this standard release was the same as indicated for this combination from Jan 27 on, so was not changed.
However, prior to Jan 27, there was no standard release indicated for a Tripower GTO with Auto Trans with either Trailering option AND A/C. This combination could be had with the 3 spd or 4 spd Man Trans (3.23 axle). I believe this was an oversight because the special order chart shows this combination could be had with the 3.23 axle as a special order. There would be no reason to allow a special order axle but not a standard release. I doubt they would have allowed the 3.55 with any A/C combination so perhaps the 3.23 should have been listed as the standard release with no special order axle indicated for this combination. But no way for me to be sure.
WITH or WITHOUT either Trailering option and WITHOUT A/C, the standard release was the 3.55 axle. You could special order the 3.23.
You could also special order the 3.36 axle with standard brakes for any of these combinations INCLUDING with A/C with or without either Trailering option.
The 3.55 axle with standard brakes could NOT be special ordered for any Tripower GTO combination (since it was the standard release for most).
Although the 3.90 axle with standard brakes was produced you could NOT order it for any GTO.
The combinations with Metallic brakes were the same but with one exception since you could not get the 3.08 axle with Metallic brakes.
The 3.55 axle with Metallic brakes was the standard release prior to Jan 27 for the Tripower GTO with Auto Trans WITH or WITHOUT both Trailering options and WITHOUT A/C.
The 3.23 axle with Metallic brakes was available for any Tripower GTO with Auto Trans combination as a special order prior to Jan 27. Again, there was no standard release WITH A/C, so the 3.23 axle with Metallic brakes was apparently the standard release despite being listed as a special order.
You could also special order the 3.90 axle with Metallic brakes (they were mandatory with the 3.90 on the GTO). A/C was not offered with the 3.90.
I have tried to be thorough here and hopefully I have not listed anything incorrectly.
If you see anything that appears incorrect, just ask and I will be happy to recheck the Axle Charts.