Ratio(s) Required in Orderto Get Close-ratio 4-speed.

[Chicken Hawk]

This transmission Dick shows in this post (number 14) is definitely a GM input shaft and in my opinion the ring(s) on GM inputs have no relation to the Stude inputs. The trans Dick shows in post number 9 is definitely a Stude input shaft so I'm still of the opinion the Stude inputs with the ring is a 2.54 and no ring a 2.20.

To tell for sure what you have, if the transmission is out of the car, the easiest way is to put it in low, rotate the input one turn and note the turns of the output. If it turns about 2 1/4 turns it would be a close ration and if it turns about 2 1/2 turns it would be the wide ratio.

If you want to pull the side cover off and count the teeth, here are the teeth counts on the two ratios: The wide ratio is:

Input shaft is 25; third 29; second 30; first 36

Cluster front is 30; third 23; second 19; first 17

Close ratio is:

Input 27; third 29; second 32; first 36

Cluster 28; third 23; second 20; first 17

You can see to change from one ratio to the other, you only need to change the input, second gear and cluster gear.

If the transmission is in the car, follow Dick's instructions in post number 9.

Hope this helps rather than confuses.

Ted

Here is the T10 out of my Chevy powered Starliner...



This was very definitely a 2.20 low transmission, but notice the one groove.

It could be Chevy pilot shafts were marked differently than Studes?

I wonder if the one Pat originally asked about and that I pictured above is actually a GM trans?

I wonder if pilot shafts can be changed between different ratio transmissions?

[Dick Steinkamp]

This transmission Dick shows in this post (number 14) is definitely a GM input shaft and in my opinion the ring(s) on GM inputs have no relation to the Stude inputs.

I'm sure this is correct. I did some more research and GM T10's can have between 0 and 6 grooves on the input shaft. AMC ones can have 0 to 4 and none of the AMC ones cross to the same ratio GM ones. It follows that the Studes don't either.

Also, I checked the parts manual. The main drive pinion changed from 27 teeth in all of 61 and the first 200 1962 4 speed cars, to 25 teeth for the remainder of 62. If I got my gearing correct (someone check me on this), then the low gear ratio went from 2.20 in 61 and early 62 to 2.54 for the rest of 62. No alternate 4 speed transmission was available during this time.

The clutch HOUSING, however, is listed as the same PN for ALL 1961 and 62 4 speed cars. This MAY tell us that while the low gear ratio changed early in 1962 production, that the Chevy style bolt pattern didn't.

There was only one 4 speed available in 63 and that was a 2.54 low.

In 1964 BOTH 2.20 and a 2.54 low 4 speeds are shown in the parts manual. One of them MAY have been standard, but both look like they were available.

[tomhoo]

Dick, you beat me to it.

I distinctly remember the 1st 200 being Close. And that was the end of the Close for Studebaker.

As far as the Chevy bell housing. I have only seen 2 4-speeds "in the wild." A Hawk I stripped from a junk yard - it was a 62 with a Chevy housing and my 63 Super Lark which was also a Chevy housing.

As far as identifying them, out of the car just put it in first and count turns. In the car it is obvious. If you get sick when you shift into 4th, you definitely have the Wide.

I would never, never, never put a Wide in a car unless it had a 3.07 rear end. This is because the Wide is a 3-speed with a "super high ratio OD." If you ever plan on winding 3rd all the way out at full throttle and shifting into 4th, DO NOT GET THE WIDE. PERIOD. END OF STORY. But maybe you have a stronger stomach than me (!) HaHa (humor-pulling your leg.)

(Actually, maybe I take that back a little. If you plan to NOT shift to 4th in the 1/4 mile, it would be OK. Because if you do shift to 4th in the 1/4, its like standing on the brakes and dropping anchor. Very depressing - even if you like Beethoven's Fifth.)

The most fantastic thing about the T-10s is that you can machine off the brass ring teeth and make a fabulous transmission for power shifting. The WIDE complains just a tiny bit when you shift into 4th, but the CLOSE is a DREAM. When you power shift it, seriously, I kid you not, if feels like you are shifting a transmission with nothing in the case. The added bonus is that the low mass of the puny T10 makes it very streetable in this form - you can actually shift it gently and get full synchronization - just apply some pressure with your fingertips.

I have a real soft spot for the T10. I don't know what I would do if I ever came across a M or N series gearset(!)

Regards,
Tom

PS. I threw in the towel and put a 2.78 low Top Loader in my Super Lark w/3.73 rear. These days, I'd break something in my body if I power shifted and so I wish I had a 3.07 "retirement" ratio.

[Dick Steinkamp]

This is because the Wide is a 3-speed with a "super high ratio OD."

Wide ratio trans is...
first 2.54
second 1.75
third 1.51
fourth 1.0

Close ratio is...
first 2.20
second is 1.64
third is 1.31
fourth is 1.0

Both have a 1/1 high gear. I don't believe any T10's (including super T10's) were made with a 4th gear overdrive. The Super T10's in the early C4 Corvettes (4+3) did have have an overdrive that worked in the top 3 gears, however.

[tomhoo]

You missed my point and my grammar too. I said, "This is because the Wide is a 3-speed with a 'super high ratio OD.'" Yes the T10 is not a 3-spd (this was obvious) but I put the OD in quotations. Quotations means its not to be taken literally. Maybe I should have said "is like a 3-spd..."

The bottom line is the Wide is not really a "4-spd" like the T56 is not really a "6-spd." The T56 is actually a 4-spd with double overdrive and yes, both 5th and 6th are over driven. 6th is actually 0.5 to 1 which is a tremendous over drive ratio.

Another irritating thing about the "Wide" is that it is really a "Close" until you get to 4th. In actuality the Wide is a Close with a "wide" 4th. If you went through all the gear P'N's and tooth counts, you will see the only difference between the W and C is the Main Drive and Cluster gear. So it is clear all they did was "drop" the first 3 gears "down" relative to the input. OD is another way to describe that. Shelby refused to succumb to the W and used a compromise. Finally, there was the N series "close ratio" Wide - a very nice 4-spd but strictly aftermarket and not a Super T-10.

If you use a W, do 3.07 or 3.31 if C, do 3.73 or numerically higher. 3.54 could go W or C but poorly in my opinion. If 4.09 or higher, DO NOT use the W! Please!

Tom

PS. There is an interesting point though, the Top Loader actually came in a structurally weak "3-spd + OD" variant where "4th" was actually an overdrive ratio (meaning less than 1:1). It had a very wide 3-spd complement of ratios. I think low was something around 3.00 or 3.08 or something like that.

[WCP]

This afternoon I pulled a T10 off the shelf for possible transport to York. This trans came from a late '62 Hawk and has the 2.54 1st. It has no ring on the input shaft. I also have another T10 with an "M61" serial no. I would guess that is for Dec. 61. I believe it is also a 2.54 1st. It is currently packed in boxes. I will have to dig out the input shaft to confirm the 25 tooth count. It is also for sale but not this trip to York. Both these T10's are the wide "Chevy" bolt pattern.

[WCP]

Checked the input shaft of the disassembled T10 and it does have the single groove and a 25 tooth count. Looking at the other T10 there is a darkened ring on the input shaft at the same location of the groove on the other trans. This may have been a dye or inked ring rather than the groove. So, the groove is not a definitive indication of ratios.