newest 720 sas

[Boxcar]

As I have very little experience with the 720 harness, my advice will be generic at best.

 Check all of you're sockets and plugs for corrosion. Make sure all of you're grounds are clean.

To me , it sounds like a grounding issue.

[godzirra]

As described in detail in the "*hiccup*" topic, the alternator/electrical trouble has been ended, it WAS the alternator, evidently 3 bad ones in a row is a "normal" experience.

 

SO that means, onto the front driveshaft, FINALLY.

 

Well I made one up real quick out of half of my old nissan shaft, and half of a Chevy 1/2 ton (using the transfer case end off the nissan shaft, and the axle end off the chevy). As some of you might have guessed, the truck turnes out to be too god damn tall for just a plain ol' U-joint to work. So I set about looking for a CV joint that had a nissan transfer case flange pattern...they do not exist.

 

So I engineered a solution by creating a Datsun-to-Chevy adapter flange.

 

This is basically a piece of 7/16" thich steel plate with a Chevy 3"x3" bolt pattern, welded to what use to be my pinion flange from the original rear end. The splines match up perfectly with the front of the transfer case and I figured what the hell, let's adapt the whole thing to run a Chevy high-angle driveshaft; parts will be cheaper, heck the whole thing will be cheaper.

 

The thing is probably not balanced, it is eyeballed as far as the density of the welds, and I used an angle finder to check and double check that the "plate" was flush with the old flange, so it's all square, but more than likely not balanced.

[mattthom1986]

So... Where are the wheeling pics? :)

[Lakec423]

Did u have any probs with the transfer case cause mines on the driver side and a yota axels pumpkin is on the passenger side

[godzirra]

as for wheeling, no pitchers yet :( as soon as I have my front DS made/installed (it needs a CV still) you bet your sweet ass there will be plenty... but there was one instance that we had like 18" of rain in a day and the whole town flooded (half the town is basically in a giant ditch). I was coming down "the hill" when I saw a river where a road use to be, we are talking a 100ft wide, 1/4 mile long, 3ft deep, decently fast moving body of water. 

 

With about .02 seconds of hesitation (and no front driveshaft) I decided, balls in. I eased into the water (came almost to the top of the 37s) and once I found the road underneath I hit about 3,000 rpm and let it out into 1st. It ripped through it all pretty well, until I hit a shipping pallet and sank the back left tire in the underwater ditch next to the road. A little bumping/jumping and we were out though.

 

I made it through just in time to get to the other side and tell a stock-height 2wd Ranger "good luck"

 

 

Lakec423, you ARE going to have a compound angle with a 720 t-case no matter what because (to my knowledge) all 720 t-cases are "center drop" t-cases, meaning the flange for the front DS is centered. This is okay though, because unless you plan on driving the thing at 65mph in 4wd you won't wear out the U-joints too bad. Mine is a compound angle, and very steep. However with the application of a CV joint you can decrease the load on one specific U-joint.

 

And really the only problem I had was the vertical angle (t-case is so much higher than the diff.) It is probably a 30degree angle which is pretty freakin huge for a SINGLE u-joint to handle. The horizontal angle you are asking about isn't going to be a really big issue since your t-case should be in the center. Now if you had a driver's side drop t-case, like from a Jeep or something, you would have to try a different approach.

[godzirra]

After a couple hours of careful grinding I found out the Saginaw simply wasn't going to work with any degree of safety or stability. Sure I could have slapped it underthere with a VERY unbalanced CV "H" link, and virtually no centering ball, but I knew that was only likely to break something or hurt someone.

 

So I set about researching "high angle Saginaw CV joints".....$849.00 for JUST a CV joint (actually the lowest I found was $595.00) or $879.00 for a custom built driveshaft. The answer isn't "no" but "HELL no."

 

I also found the Tom Woods "Superfle" 1310, 1350, 1410 U-joints. They are supposed to allow up to 40 degrees of flexability with a single u-joint. (these are more popular for front DS applications as they will vibrate somewhat no matter how balanced).

 

My internal debate is this: I really don't need any more than a 1310 u-joint to handle my little 100 horses, but for some reason all the driveshaft places keep teling me I should go with a 1350 or bigger... I know these are 'Merican parts, and this topic might be better suited for some place like pirate4x4, but I figured I would check here for anyone with some further experience.

[godzirra]

Okay, long time no update due to classes and work, but I finally got the front driveshaft figured out (I will make a specific post about that with pictures) and I have only gotten to mildly test/have fun with it so far.

 

However I have been daily driving the thing about 30min one-way for quite a while now and it handles well, no sports car but good enough for my taste. Anyway I am now sick of that loud ass ratcheting sound when ever I take it out of gear and cruise. It is doing it EVERY time no matter what now and needs to be seen to.

 

So we narrowed it down to probably a throwout bearing issue, I am just wondering if this is a "pull-the-motor-and-transmission-then-go-have-the-tranny-rebuilt" issue, or if I can just take the T-case loose and slide the thing back...

 

here is a pic of the rear hanger holding the leaf springs, right in front of the drop-out transmission mount member... I don't really see any way to get the tranny out of there without either lifting the cab or pulling the motor aswell...

 

[godzirra]

Basically we have 2 yokes, both 1310, one from an old chevy 1/2 ton and the other from a cherokee, pressed into a piece of DOM tubing with the same I.D. as the yoke pieces O.D.
 

Then I went and had it MIG-P welded to fill any gaps between the two so it ain't moving. *yes I know the yokes are rotated exactly opposite, I took the front one off and turned it later*