t-14 with tera low gear set or sm465?

i've been pondering the last few days about this. how well would a t-14 hold up to some serious wheeling with a tera-low kit in the d-18? I have a '71 with the v6, t-14 and 4:27 gears with an overdrive. I also have a sm465 sitting in the barn along with the bellhousing needed to do the swap. The trans (sm465) should be gone through before installing. I would need the adapter for the t-case too. it would almost be the same money between the two but not sure how well the trans would hold up verses the sm465.

 

The Tera gears are definitely less work. But you don't get nearly the reduction with the Tera gears that you would with the truck 4-speed.

Is the T-14 the weak link? I suspect one of your axles would pop first, but maybe not. Typical failure is related to impact load, so a lot would depend on your style of driving.

It's hard to beat the truck 4-speeds as an upgrade... if you do good work, the 4-speed should be worth more at sale time than the Tera gears.

 

Agree with Tim.

 

It takes less energy (torque) to turn a lower geared transfer or diff. The real work is seen by the diffs and tera gears so I agree with Tim.

 

The T14 is the weak link , as the others have said

 

The V-6, SM465 with 4.27 gears is an awesome combination. I really like the way it performs.

 

i guess it would be easier to find replacement parts for the 4-speed as opposed to the t-14 too huh?

 

scott, do you run an od with your setup? i would have to purchase another bull gear in my od to run the 465 right?

 

No. I thought about it. I figured I would do the 4.3 ltr TBI motor to get better gas milage, and it did help. I think I my put in an overdrive in it one day.

 

Oddfire,
So you have a Warn OD with your T14? If you go with the SM465 you can get a 10 spline output shaft with the conversion kit to allow use of the current OD setup. The Novak kits come with either the 6 spline or a 10 spline output shaft.

Don

 

This.
I converted from a T-14 and OD to an SM465. Make sure you get the right shaft.
I agree with the others, ditch the T-14. I broke mine then went with the 465. It's been trouble free ever since.

 

As someone who rebuilds a LOT of T-14's (when parts are available) I also say swap transmissions. Quality or oem parts are getting hard to find for the V-6 T-14 and it is not the strongest transmission. I see lots of them with broken main drive gears and cluster (counter) gears. Usually 2nd gear and the 2-3 synchronizer assembly is worn as well. Even good cases are getting hard to come by.

 

alright it looks like i will continue to gather parts for the sm465 swap. i will have to look to see what it costs for that conversion for the od.

 

so you run an od with your 465? did you have to get a different bull gear?

 

X2, I ordered my adapter from Novak and still run the OD. Went together very well.

Just for reference on overall "crawl ratio" with the 2 set ups.
T14 1st gear 3:1, Terra Low 3.15:1, Diff 4.27:1 = 41.6:1
SM465 1st gear 6.55:1, D18 2.46:1, Diff 4.27:1 = 68.8:1

Still one of the best upgrades I have ever done. Much less speed to crawl up, over and down. Much less skinny pedal which equals less abuse and you get a super strong tansmission.

 

One more consideration for you to get confused about. there are other after market D18 gear sets available.
I chose this one because the amount of work for the SM465 and the cost is close to the same, I estimated it at $1500 ish.
http://www.earlycj5.net/forums/show...of-O-brien-4-Wheels-West-is-still-in-business

My T14A is good, but I have not done much extreme stuff. The 3.6:1 with 4.88s in the axle is nice. I do not have many miles on it yet.
The conversion for the Rockeaters (assume the Terra Low is similar) is not bad to do. I had some assembly problems, but those were my mistakes and impatience.
Leaves the stock look and no other changes besides the D18.

SM465 things to change:
bell housing
SM465 adapters, make sure you get the right output shaft.
Crossmember
front drive shaft, be careful to check the angles
rear drive shaft, be careful to check the angles
floor pans

When ever this question comes up I must point this out.
I do not have the tools, skill or patience to do the SM465 swap.
I even got one cheep.

Which ever you choose have fun, be safe and take pictures for us.
Jim

 

Would anyone recommend running the truck 4 speed and the d18 gear reduction together? This would bring the crawl ration into the 88 to 1 range.

I have questioned this because I have a t18 and 4.10 gears with the stock d18 t case and has been great with a 64 to 1 crawl. Huge upgrade over stock and runs the Rubicon well each summer. If i added the d18 t case kit it would put me into the 80 to 1 crawl ratio. Is anyone running this and does that work better all around? Just curious if anyone has this combination.
Peter

 

I thought about this but could not justify the cost. A few things to remember.
The Terra Low gears by themselves are not cheap, I think in the $700 range.
If you have and want to keep an OD the costs go up over the $700 range, I believe Herm has them listed for $940.
I know 4.88 D27 axle gears are getting hard to find but it may be a cheaper route. I am not sure what year your Jeep is but Randy's sells 4.88's for 65-71 and maybe more years for rear 44's for about $260. My 71' with 4.88's has a crawl ratio of 78.6:1.