very true. The biggest difference between torque and horsepower is that torque is multipliable(which is what were all doing when we change gears) and horsepower is not.

 

This mod keeps getting more and more expensive.

On that note how do I measure for drive line changes? Can I just add the 6 1/2 inches to the front shaft and subtract that much from the rear?

 

They all do.

You can save some pennies building a square front DS. I had one, worked okay but pretty ghetto. Very strong though.



You are on the right track, but honestly it would be best to have the dual assembly at least built if not actually installed before you start measuring for new driveshafts.

By the way, have we established whether you have a V6 or a 4CYL... because that will change everything...

 

how did you build that front shaft???? and would it be ok to use it in the rear if its that strong? just asking cause i have 3 trasfercases out back and plaing on using all three and need some strong stuff

 

Sure it would work...as long as you dont go over about 15 mph.....

my main beef with square shafts (besides the god-awful racket and inability to balance) is the fact they when they hit a rock ...they dont slide over it like a round tube...they push the shaft over the rock or break it This put a butt load of stress on the t-case bearings and output shaft and seals creating leaks and/or other problems

 

ah ok then i guess i wont be doing anything like that then thanks

 

What abut it?

In double low, I never get above about 1000 to 1500 RPM, so I'd imagine that my torque even multiplied as it is, is not strong enough to rip out my mounts.

I have a gutless, torqueless motor. I'm not worried about any of my driveline mounts.

 

4Crawler has ya' covered:
http://4crawler.com/4x4/CheapTricks/MotorMount.shtml
and it's not the engine torque that's the problem, it's the torque of the driveline, multiplied by the low gear ratios.
think about it- 95 lbs torque, multiplied by a 4:1 ratio= 380 lbs. some of that torque is absorbed by the engine/trans mounts, the rest goes to your tires. if the tires bind, the torque has to be absorbed by the mounts. weak mounts = broke mounts.

 

Just search "square shaft" and you'll get a lot of info. It's basically two pieces of trailer hitch stock mated to Toyota ends.

The square shaft is strong in regards to impacts. I suppose it would be stronger under torque load as well, but generally stock Toyota joints are used so a square shaft has similar weaknesses to a "stock" round shaft.

That is a very true statement. I never could get mine to be just right. Your speed is limited and noise is high. I have heard that some have better luck however. It's the cost (under $50) for a burly front DS with over 12" of slip that attracts most to the idea.

One could probably add some tube to round it off if they were so inclined. I personally view the square DS as a temporary cost effective solution to dual cases or after a SAS. Once you save up some more funds, a conventional well made shaft is really the only way to go.

 

Interesting, I've never heard of that happening. I was most worried about breaking the mounting bolts that go into the block or the block itself. I am using 2 transfer case mounts (one on each case) so that should help spread to forces and stiffen it up at that end.


On the motor end, the chains do have enough slack that the rubber still gets stretched some before the chain takes over.

 

4 cylinder 22re, 5 speed manual if that helps any.

 

On the drive shaft part I just had a driveline shop re-tube my existing shafts. It was about $60 to re-tube and rebalance each one here locally.

 

I went this route, http://www.pirate4x4.com/forum/showthread.php?t=154338 since I had the motor out anyways. Vibrates more than before.

 

Don't forget pinion rotation, depending on rear lift and over all angle of driveshaft.

I rotated mine before I tried it without, mines a DD and wanted to deal with the rear driveshaft once. Really wasn't as bigga PITA as I first thought it would be. Reenforce the aftermarket spring perches like Toyota does if you go that route


Dual cases was the best mod I've done yet. In hind site I would've been better off with dual stocks than 4.70 to begin with.

If your going to lift your truck do it before installing the duals, so you deal with the length/angle think once. Plan out you build, so to speak you'll save cash in the long run.

 

There was never any disagreement on torque multiplication.

I understand very well how torque works, thanks.

The original question was "have any of you guys with duals ever broken an engine mount".

I answered no.

I also said I'm not worried about it.

I am still not.

I do think that it is a valid concern. I only answered in the context of my own truck and my own experience.

 

I never broke one either, but had the motor out anyway and Murphy is not my friend.

My Sky crossmember uses 2 TC mounts so maybe the motor mount thing was overkill????

Sky crossmember with dual mounts is another story, every mod to solve a problem is the potential for another problem. Good times.

 

I thought I had broken a mount, but checked and they were OK. I think the beefy crossmember and two tranny mounts helps A LOT.

I do really need to chain down the motor mounts though ... I hear it REALLY sucks to break one.