Tranny swap

[navybee]

Hello all,
I currently have a 79 CJ7 with a 360/t150/d20tc. I am interested in swapping in a auto. The choices I have are a th400/qt out of a 75 j20, or a 727 auto tranny with 208 tc. Which would be a better choice strenght wise and ease of intallation? Other mods I have done includes: pw steering and brakes upgrade, fiberglass tub and all most all the other body parts, one piece axles, painless wiring, hei, stainless brake and fuel lines, swinging the alt up like a chevy, and remote oil filter & cooler among all the little upgrades.
Thanks for any help,
Rob

[jeepsr4ever]

Your rear driveshaft become very short. It has been done lots of times just be aware you will need a high angle CV shaft. You could go 904/999/998/727 and a dana 300 without adaptor or a TH400-dana 20 with the factory adaptor and the factory 20 case. The Dana 20 had two different bull gears and the early ersion matched the th400-dana 20 bullgear so you may need the T case from the original combo.

[navybee]

Thanks for the info. I do have a dana 300 in storage. With the 727 do I have to worry about the pan. I only have a 2 1/2 lift.
Thanks,
Rob

[1980_Cj7]

With the 727 do I have to worry about the pan. I only have a 2 1/2 lift.

YES!

[Lifted79CJ7]

Steve Friend on the Jeep-L list on yahoo is doing this swap right now. Here is a link to some clearance issues, even with a modified pan:
http://www.jeepshots.com/users/sf/JeepMod/

"I am back to not having any clearance to the drive shaft again. The
clocking ring did it's thing in getting the Tcase out of the way and moved
the drive shaft out away from the pan, but it also moved it up and I only
have about 1/4" clearance. I am hating this project.

I have a call into Tom Woods to see what he thinks.

SF (made myself a two wheel drive rock crawler!)"


A reply to an earlier post about the differences in the tranny's:
"The TF999 is the lighter duty of the two trannys, The cases are the same between the TF727 and the TF999 But the pan is slightly different to clear the front driveshaft's on wranglers and cjs.

The TF727 was used in Wagoner's and full size jeeps for a couple of reasons. One, you didn't have the clearance issues you did in the wranglers because they are full width. Two, Much heavier then a wrangler so they needed a medium duty tranny to handle the V8 horsepower and the weight of the fullsizes.

Think of it this way, in the Chevy word the TF999 is made for cars or 1/4 ton vehicles, The TF727 is made for trucks or 1/2 ton and up vehicles."


And here is another post:
"The 999 and 727 are Mopar trannies which Jeep 'borrowed' and the internals are identical to their Mopar brethren. Save for the portion of the case that bolts to the engine and the output shaft and tailhousing adapter (in most cases), they're externally identical as well, so the pans are not CJ/Wrangler specific. The 999 is a medium duty trans based on the 904 and was used in 6 bangers on up to small V8's...the version used in Jeeps is a low gear version similar to the Chrysler 5th Ave 318 V8 version used in the 80's. The 727 is heavy duty and obviously physically larger and beefier. The 999 is plenty for a mildly built rig, just keep the TV linkage properly adjusted, keep it cool, and put a real vent on it if you're going to run it through mud or water."

I also did the tf727/dana300 swap in my CJ7, but I was running about 9" of suspension lift, so clearnce wasn't an issue for me.

Another site to look at is here:
http://www.jeeptech.com/convtrans/conv727.html

Hope this helps!
Jack

[dan58]

I run a TJ999 with a 360. It's a MUCH tougher tranny than it's given credit for. Keep it cool, and you'll have the hot ticket. I also run a D300. I have twin sticks, and I couldn't be happier. With that combo, you won't have to worry about front DS clearance.

[dbesade]

I would simply find an AMC Pattern TH400.. get the adapter kit for the Dana 300 and have no clearance issues. But thats my 2¢

-Dave

[tufcj]

Isn't the 208 a driver side drop? That would mean a front axle swap.

Bob
tufcj

[navybee]

Thanks for all the info guys. Sounds like I will call the guy about the 400, then call dad to get the d300 out of garage and bring it up. The tranny allready has the amc bolt pattern. I don't think $200 is to bad. Any other issues I should be worried about?
Thanks,
Rob

[jinpdx]

The 208 comes in both driver and passenger side drop. The 400 is a tough tranny, but it tends to eat up alot of horsepower to run it. If it is a amc 4x4 400, then it probably has a 10 spline output shaft specific for the quadratrac transfer case, you will have to change it to run any other transfer case.