Scout II 727 Output Shaft Conversion

img_1180.jpg


The finished product, ready to install
 
It's been a long arduous journey,with at least one major setback, but the project is complete. Preliminary testing in the driveway points to a major improvement. Crawl speed in low/low 1st gear at 2500 rpm is less than normal walking speed, at idle it's ridiculous, about, well really slow.
The gearing is so low that the brakes are over powered, and thats with 4 discs and hydroboost. Looks like there will be some learning how to drive again...

Trail testing to follow, stay tuned...
 
michael mayben said:
we're doing a conversion onna sii 727 in order to be able to stick a klune v unit in front of a married d20 transfer case for ihon member terry d.

This involves replacing the oem output shaft in the sii trans with an output shaft spec'd for an early/mid 80's fullsize Jeep with a 727 in front of a d300 case.

In order to do this, the entire transmission must be gutted, as the output shaft/planetary assembly is the last component set to come out of a 727 during service, and the first assembly to go back into the case (after the overrunning clutch has been freshened).

And of course, ya gotta have the correct donor parts for doing this.

About a year ago, I ran up a comparison of the various output shafts we encounter when playing with ihc stuff. This shot shows the four shafts we most commonly encounter, though there are others that were used in tf727 applications used in other oem applications. In this thread, we addressed the differences in the shafts and their respective mating planetary carrier splines:

t-407/tf727 variations and parts differences - IH Parts America

In this thread, we'll concentrate on the other end of the output shaft, the "Jeep end", as we build this trans for the klune.

The subject transmission was rebuilt a few years back by a commercial shop. Then maybe a year ago, it was used as a demo for our club folks (IHSTO) regarding periodic maintenance (fluid/filter change and band adjustment), along with having both of the shifter shaft seals replaced with the trans installed in the girlscout. So we anticipated that this tranny would not require any freshening since it's performed well. Wrong!

Turns out this unit was cobbled when built. None of the rump retention bolts matched, all had heads stripped off by an impact wrench and two of the bolts were partially backed out. No attention was paid to the fastener torque at all, old soft parts were re-used, the rear drum and drum support had seized at some point and then obviously re-used when the trans was put back together. The valve body is a homebrew mish-mash of crap parts. And the low/reverse band has only been partially engaging based upon a really strange wear pattern seen on the friction material and the drum (which is not usable). The worst part,...the bull gear retaining nut had been severely fooked onto it's thread on the end of the output shaft. It took me more than two hours of progressively longer cheaters and the gas axe to finally persuade the nut off.

So along with the output shaft swap, the tranny gets a full build using the B&M -supplied parts. We're leaving nothing to chance here.

The purpose of this thread is to address prepping the sii trans for the klune install, we're not gonna go through a step-by-step tranny build.

Terry brought up a suggestion for doing this in another thread, so I'll move his post to this thread.
Click to expand...

Hi michael, I realize this post was a while back but wondering if you know the part number for the Jeep output shaft in your photo comparison of 727 output shafts? I'm looking to bolt a tf 727 to my Jeep d300 tc but the current output shaft I have in my 727 is too long. I need one that extends from the main housing by ~ 7" and has 23 spline. Looks like the one in your pic would do the trick
 
You must log in or register to reply here.
Back
Top