Anybody know what size gears came default in the BW t-10 in 1965? I have an all original '65 I am parting out but keeping the drivetrain to put in my '66. The '65 is not a gran sport, but it did come from the factory as a 4 speed and with the 300 Hi-Po engine. How rare is that, I don't know, but if anybody does let me know. I was wondering what gears came in the tranny, and if GM would have put a posi in the rear. It's a 10-bolt, but there is no tag. I have tried spinning the wheels but they don't spin the same direction. Which I know means it's not a posi, but could the posi be worn? Thanks in advance for any help you might offer.
Can't say for sure, but you can check it when its out. Starting in first, spin the input shaft once and count how many times the output shaft turns. If you don't have a shifter on it and don't know if you've put it in 1-2 or 3-4, the more rotations is the numerically lower gear. 4th gear will be 1 to 1. Anyway, if it turns like 2 and a half times, its got a 2.50 1st gear. Get it? So its not an exact formula, but it'll get you ballpark. Plus you'll know for certain if its a close or wide ratio. Good luck! :3gears:
The 65 and 66 GS used a special T-10 with high nickel gearset. regular T-10 will work fine, gears just not as beefy. GS versions have a GS cast into the case and rings cut unto the input shaft that denote the high nickel gears. Patrick
Thanks Guys I guess I'll have to pull the tranny to find out. If I open the case is there a ration of gear teeth/ inches I could determine?
Have to agree with cheryl, the B-W t-10 for 65 was a close ratio 2.20 to 1. the GS had a 3.36 rear with 4 speed and a 3.08 for automatic. hope this helps Al :beer
I am convinced the 65 Special and Skylark came with the wide ratio 4-speed gearbox, and the 65 GS Skylark came with the close ratio 4-speed box. My 65 manual shows the wide ratio 4-speed box for the Special and Skylark, but the 65 GS Skylark trans here and all the others I know of have the close ratio. My 66 manual shows the close ratio 4-speed trans for the 66 GS Skylark, but shows the 3 speed as the only trans available in the Skylark and Special. The 67 manual also shows the 3 speed as the only trans available for the Special and Skylark. I dont know if you could have special ordered a 4-speed for a Special or Skylark in 66 and 67, but I am sure it would have been a wide ratio like the 65 if available. The wide ratio gives the smaller 300 or 340 more grunt off the line and uses a broader rpm range. The 401 does not need that kind of help to get going and will perform better in all gears through a shorter rpm range. Clear as Mud Cheryl
Well I stand corrected. Thanks for setting it straight :TU: When I rebuilt the T-10 4 spd in my 65 GS back in '78, I was almost certain that it was the wide ratio box. I looked high and low for documentation last night but couldn't dig anything up. And I thought I had a decent memory............jeeeez, this gettin' old is a b****. But its better than the alternative! It was the original trans in that car, everything on that car was original.
I have the casting number I found the casting number on the tranny. T10 1B WG DIV. Any hints. I found some info online that says this is a 63 tranny that went into hi-po chevy's but I don't know how much truth there is to it. So I thought I'd ask the experts. So what do you think Cheryl?
Roy, send me a picture of the transmission and I will tell you what it is. Need to see the input shaft, and both sides of the tailhousing--where the shifter mounts and the casting numbers on the other side. Your car is extremely rare--more valuable than the '66 you are putting the stuff in. All the '64 and '65 Skylarks with a 300 engine and a 4-speed came with a wide ratio BGW T-10 (I have a '64 and a '65 both with 300 engine and 4-speed and know for a fact). I also have a '65 GS with a 4-speed and it is the close ratio box. Tail shaft housing is different between the GS and regular Skylark. GS tail housing has two different shifter mounting locations on it--one is 1" further forward than the other. The regular skylark has only one mounting position. Regular skylark tail housing should say T10-7D on it, and the GS one should say T10-7K on it. It also has the letters GS cast into it between the shifter mounting holes (can't see it with the shifter bolted on). The mounting pad location for the rear transmission mount is also in a slightly different location on the GS tailhousing--it is about 1" further forward than on the regular skylark tailhousing. The GS tailhousing also has an extra, smaller rear mounting pad that is not used. The regular Skylark tailhousing only has the one. stonesautomotive@juno.com
The Old Facts and Figures book listed the ratios for the two different 4-speeds; one for Specials, Special Deluxe and Skylark, another for Wildcats. In another section of the book they detail the GS trannies- they are the same ratios as the Wildcat. 3-speed 1st 2.58:1 Wildcat 2.49:1 2nd 1.48 Wldcat 1.587 third 1:1 4-speed 1st 2.51 Wildcat 2.20 2nd 1.89 Wildcat 1.64 3rd 1.51 Wildcat 1.31 4th 1:1 After driving the Wildcat with the close ratio trannie, I wish it were the other one, it is a bog meister with the 2.2:1 1st gear. Thats why I was thinking that a 3-speed GS would be extra cool. Ted
I have heard the early 3-speed GS Skylarks were fast. The gearing is similar to the TH400 so they should be. I know where there is an original 66 GS Skylark convertible 3-speed with a blown motor. I am waiting for the Chevy loving owner to get tierd of trying to find parts for it and sell it to me. You could not torture the location from me! Cheryl
