Hey guys, I am converting my '63 Pontiac T-10 from a close ratio to a wide ratio. I rebuilt this Trans once (I did it twice, so I did it right). So, I have some knowledge and ability to start with. It made it from here to Norwalk & back fine, so must be OK. Here is what I am working with: Existing: close ratio '63 T-10 T10C8 cluster 28,23,19,17 and main drive gear T10 C16 L27-s36t New: T-10A8 cluster 30,23,20,17 Main drive gear T10D16 L25-s36T My questions are: 1. I know I have to change the main drive gear, and I have an NOS cluster gear that goes with it. I ***ume I have to change both of these right? This is confusing b/c my parts book says that they offered the 25 tooth main drive gear in '63 but only lists the cluster that goes with it for '62. I don't think the year of cluster Manuf. makes any difference it terms of fitment, but it got me thinking as to whether I needed to change that or not. Sure seems like you would though. 2. The cluster tooth count numbers - which number applies to which gear? 3. Do I need to replace 1st, 2nd and 3rd gears with the above swap? I need a new 2nd anyway b/c it is worn to the point it will not stay in gear (got the science on this already). It looks to me from my T-10 parts list that they only made one tooth count for the 3rd gear and one tooth count for 1st gear, but the cluster tooth count is different. Thanks for any help. I am trying to get all the stuff I need together before I pull out the trans. I think I have sources for all the stuff except possibly 2nd gear if it requires specific tooth count to match with cluster. I also need the speedo circle gear, which needs to be changed to a 1.84" OD.
go to www.umtrnorth.com and post this on the "****** tech" section of their forum. It is a stick shift only website. You will get a quick reply.
Yes, because as tooth count changes at one end the other as to as well. Thats how the ratio's are made up.
Now i'm just as confused as you. After rereading what you wrote it would seem that only second gear would be changed. Then theres the inputs, there both 30 teeth but differant tooth count on counter shaft. I will admit that I never got into a T10 but have played with Muncie and Saginaw.
The input shaft, cluster gear, 1st, 2nd, and 3rd gears all have to match. The reverse gear is the only one that stays the same. If you have a heavy foot or do any drag racing with sticky tires that T-10 will give up in a hurry if you are putting this in a heavy car.
I know it is not a really stout trans., but I am not going to beat on it too bad, & it all just bolted right up for a reasonable price. Could have done a Richmond possibly by now with the tinkering, but there are install issues with that. I went back to a peg leg to go a little easier on it, but with the current set-up there is no danger of any stop-light drags.
Yeah I know. That is what I think. The 30 main drive gear on the input shaft matches up with the cluster I got, so that is covered. I am kind of confused as to which gear in the cluster applies to which gear. Even with all the exploded diagrams I have etc., I can not figure it out 100%. Once I know that I will know which I have to change. Pretty sure it is just the 2nd, which is worn anyway. The one thing I do know is that starting out on a hill a 4000# car with a 2.20 1st and a 3.08 rear does not work very well. I knew this going in, but I don't want to go up on the rear end b/c I want to do a lot of Hwy driving. I have a car with a 3.42 and that is just no good at 70 MPH. What I really need is an old GMC grain truck trans. I just hate tearing stuff apart that "works" before I know what I am in for.
Did a quick lil search on T 10 parte on line. Seems the answer maybe as simple as a 1st and 2nd design. It's possible the centerline between the main shaft and counter shaft are differant. If this is the case then the parts you have won't work. Here's hoping that someone will confirm because I'd like to know as well.
All you have to change is the cluster and input shaft. You do not have to change the 1st, 2nd, or 3rd gears. They were the same tooth count for both close and wide ratio pre 1964 transmissions. -Matt
This is good news. It would save some $ if all I had to replace was my worn 2nd gear. So, does that mean you can use either the 30t or 32t 2nd gear with either cluster? '63 is funky b/c it has the nut on the main instead of a snapring and a shallow bearing. I was lucky to find a 25T with the threads. JG- Check this out. Link was not working right when I tried it just now, but usually OK. The BW catalog pgs with the part Nos. exploded diagrams etc. are all in PDF form here. You can download and it helps figure it all out. http://fiedlerh.home.att.net/BW.htm This link works and has the same PDF. Very helpful: http://www.autogear.net/pdfs/T10 booklet.pdf
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