What transmission is sitting in my garage?

My Intermediate began life as 2 different jeeps:

1973 w/ 304
1975 w/ 258

It is more 1975 than 1973. I used the 258 and the trans/xfer case from the 1975.

So,... what transmission is sitting in my garage in Ohio? (I now live in Florida...) Is it a T-15? If so, is it geared lower than the T-14 in my Jeep now?

Thanks all,


mug

 

My knowedge is that the 258 came with the T14. But check out http://www.novak-adapt.com/ for tons of info.

 

73 FSM lists T-14 for all 232-258 and T-15 for all 304 equipped CJ's with a T-18 being optional for both.

 

Look at the side of the transmission. If it's marked T15 or 1307 it's a T-15. If it's marked T14A or 1302 it's a T-14.

From 1972 to 1975, all 304 CJs and 304 3-speed Commandos got T-15s. All 3-speed 232/258 CJs or Commandos in that era got the T-14. From 76 to 79, all 3-speed CJs got the Tremec T-150.

IMO the T-14 is not stout enough for V8 power. Additionally, the T-14 ratios are not well spaced (2nd is way too low - no passing gear). The slightly lower 1st gear is not a compelling reason to use the T-14. I am not a big fan of the T-14. The T-15 is stronger, has better ratios, and is way more desirable IMO. Both of these transmissions will bolt up to either the 258 or 304.

The CJ T-18 from 71 through 76 was a close-ratio transmission and not available with the V8. The CJ 304 reportedly was available with the wide-ratio T-18 from 77 through 79.

 

What Timgr said. I can also confirm that '77-'79 you could get the T-18 behind the 304 V-8 as I've seen several bone stock CJ's in that configuration.
I will also confirm that the T-15 is much stronger than the T-14 having rebuilt many of both transmissions. If you see them side by side where you can look at the gears and shafts the strength difference becomes obvious.

One other thing Tim, I've found the I-6 version of the T-14 has a different second gear ratio than the V-6 version. I forgot to write down the numbers to figure out the ratio difference but there is a difference as the cluster gear and second speed gear tooth count and diameter is different. Irks me that I forgot to write it down and figure out the ratio's.

 

That's interesting - I remember reading that in another thread too. When I had my CJ-6 with the T-14 and 258, I really hated the big gap between 2nd and 3rd. On long steep upgrades (desert highways particularly), I either had to downshift and really wind it out, or lug it down in third and lose speed. I'd guess that the V6 and I6 ratios aren't that different, but it would be good to confirm the numbers.

 

WOW, thank you all. I am shooting a link of this to my Dad. If it IS indeed a T-15, I might do a swap. I absolutely hate the gear spacing on the T14.

 

So, I read through the novak links. It states the following about the T14:

The T14 always used a 10-spline transfer input gear.

It states the following about the t15:

The T15 always used a 6-spline transfer input gear.

I am unfamiliar about transmission lingo. Are they speaking of the splines that go into the transfer case (what it sounds like to me) or are they talking about the input splines to the front of the transmission from the flywheel?

If it is the former, I am good to go for my swap. If it is the latter, I guess I'll have to find another flywheel that will accept 6 splines...

 

That's the gear that goes into the transfer case and bolts to the main shaft coming out the back of the transmission. Use the gear that goes with the transmission. I would call this the transmission output gear, but I suppose it's really part of the transfer case.

BTW the flywheel has no splines. The splines are on the clutch disk.

 

So, the $64 question is this: Is a 1973 T-15 (From a V8 CJ-5) a direct drop-in replacement for a T-14 in a 1975 CJ-5 with a 258?

 

I'd have to look up the details of driveshaft lengths and mounting, but otherwise yes.

Ok, model 83 with 3-speed all use the same propeller shafts. The mounts may have some minor differences that you'll have to sort out. Should be very easy though.