Hey ya'll. Answered my C4 questions on my own kinda.. just decided to pull it apart and pray it'd go back together with the new tailshaft :D Now, on to my next set of questions..

I have a Dana 20 out of a 69 or 70 EB. (relatively certain anyways.. mfg date stamped on the case is June/69). It's a t-shift t-case if that helps at all.. my questions are..

1. What's the low range reduction in this thing? I've seen it referenced a billion different ratios.. but I think its 2.46:1. I've heard that the 6 cylinder 20's are different than the 8's... the early ones are different than the laters production ones.. all kindsa crap. I'd just like to know if I have a 2.46:1 case or not..

2. Where can I find a C4 to Dana 20 stub shaft? I guess I managed to get a 20 stub shaft for a manual trans from my local vendor here.. even though he KNEW I needed a freekin auto shaft. And the manual shaft is about 1.5" too long? I'm hoping he'll be nice and cough up the right shaft for me (since I was overcharged to start with..) but if he doesn't... where can I get one for a decent price? I hope I don't have to drop another $100 for one of those things.

Thanks.
:skull:

I can answer one of the questions. I can pretty much guarantee you have 2.46 gears because even if it is true that 6cyl. xfer cases were different than the 8, only '66 and maybee early '67 broncos had 6 cyl. in them. 1973 is when they went to the "J" shifter which are not as low geared.

Yeah, despite what some may say, almost all EB D20s had the 2.46 gearing.

Maybe I misunderstood Albino Man, but it sounded like he was saying they stopped making 6 cyl broncos after 67. (I think he meant different ratio xfercases, but....) Well they did make 6 cyl broncos into the 70s... I've got a '69 EB w/a 6 cyl out behind my house.


As for your tailshaft.... maybe it's the correct tailshaft, as the C4 used a different adapter to connect to the D20. If you don't have it, you're probably fawked. Plus, you'll need the C4 adapter just to get it to bolt up anyways. These adapters are rare, and in great demand. I think Advance adapters makes one though... but be prepared to get raped in the wallet. $$$ :eek: Also, the length difference could be due to the possiblity that the adapter is from a 6 cyl bronco... they are supposed to be shorter (by about 1.5") than the v8 adapters. Hope this helps!

The T-shift cases are 2.46 and the J-shifts are something different/higher (lower number). Is doesn't matter what engine. THe 6 cyl were more likely to have 4.10 or 4.56 axle ratios. I have a 68 that was a 6cyl and have seen 69/70 model sixes, and think I have seen later ones but can't swear on it.

T-shift D20s are 2.46:1, and the J-shift are 2.34:1.

I think this is like the 31 spline rear axles:rolleyes: .

I have 2 J-shifts (both '74) and 3 t-shifts ('69, '69, '71) and the gears inside are all identical between them - 2.46. same tooth count, same diameter etc. Unless they had been re-built before and had gears swapped.

Only difference is the J-shift rear output was a larger main dia than the t-shift, and the T-shift front output was a larger main dia thant the J-shift.

I have been told the 6 cyl T-cases had 2.67 gears in them, but I have not been able to verify that.