my junk yard truck

[lapeer20m]

Originally Posted by GoneCamping

I somehow picture that drive shaft shredding itself to pieces very quickly.

Thanks for the advice.....I was thinking of just finding a #40 sprocket that would slide over top of that driveshaft. I guess i better re-think that.

perhaps find an adapter that fits snugly inside the driveshaft and has 1" solid steel shaft to mount bearings and the sprockets onto.

or I could find a solid pto shaft that uses the same size U-joints as the current setup.....

I think you just helped to avoid a big problem.

[GoneCamping]

Hollow drive shafts get their strength much like an egg shell does. The overall design lends itself well to providing torque in it's tubular design. The ends of the tube fit over and attach to solid inserts. The point where you want to place your sprocket is hollow, and has no real strength there. Now if you had a solid shaft (like the front shaft on my Jeep) then you could probably run a sprocket off of that. But the hollow shaft won't take the stress in the middle of the shaft like that...

[the_experience03]

Those electric actuators are what would allow you to have a lincoln locker and are what would be replaced by the posi-lock cables. With the rear end lincoln locked, you could flip the switch and only the short side axle shaft would be turned. It would still kinda sorta function like an open diff in that only one wheel would be powered.

[lapeer20m]

Originally Posted by the_experience03

Those electric actuators are what would allow you to have a lincoln locker and are what would be replaced by the posi-lock cables. With the rear end lincoln locked, you could flip the switch and only the short side axle shaft would be turned. It would still kinda sorta function like an open diff in that only one wheel would be powered.

i get it now......

it would be just like welding the spider gears in your dana 60 front axle and unlocking one of the manual hubs....I wonder if the added stress of that would cause the CV shafts to explode immediately, or if i'd get a few hours of enjoyment out of her first.....IF i go that route, perhaps i'll find another identicle differential to expierment with. If i don't like it, i'll pull it out and install the open dif....Lockers sure do seem attractive to me....

Everything i read tells me how frail and worthless the GM ifs system is. The k2500 heavy duty does have the largest of the IFS units...the 9.5 I think it is. I started with very low expectations when i began wheeling with this truck. I can't believe the places the ifs allows me to go. My 38" swampers take me places people with solid axles (especially dana 60's) need 44's to get through because the pig hangs down so far. I beat on this truck quite a few times out on the trail and the only drivetrain/chassis component i've had to replace was a tie rod end...

Now i would estimate that the truck weighs 1,500-2000 pounds less than stock. I found a website that sais the truck weighed 4,387, but didn't specivy 2 or 4 wd. I'll put this truck on the scale eventually

[the_experience03]

I think the CV's would be ok as long as you took it easy on them. When you had the thing unlocked, it would be wise to avoid putting the wheel at full lock and hammering the throttle. With your lightweight, you should be fine. I'm yet to pop a birfield in my truck because I follow my own advice...lay off the skinny pedal when turned.

[paul iossi]

Check your farm supply store for a PTO shaft that has compatable U joints for a driveshaft, they will probably have the chain and sprockets also. You should probably think about drilling the pinion sprocket and bolting it to the yoke as well as welding, i think that the yoke is probably cast or nodular iron and not steel. Use a high nickel content welding rod for cast iron, preheat your parts and cool slowly after welding. Make sure to install an adequate shield to deflect all shrapnel down when something grenades.
I think that with the minimal amount of weight and relatively low torque of the stock small block that this setup has a lot of potential .

[the_experience03]

#60 chain, especially ina double configuration would be WAY more than sufficient. That's what the big mud draggers use with their 1500+ hp which propels them down a 300 foot mud track in well under 3 seconds.

http://powerproracingproducts.com/categories/63.html

[imadumass]

Oh, boy.

I must mention something ...

Did you realize that you have wasted a HUGE amount of time here? You do realize that the front axle, if turned around backwards, operates the same way as the front axle in your truck, right? In other words, if you turn the pinion yoke the same direction as the front, the rear will push the tires, while the front will pull the tires.

In other words..... let me see if I can explain it in simple terms....

turn the front driveshaft counterclockwise as viewed from the rear of the truck.
the tires pull the truck forward.

(*install the rear axlehousing like the original solid axle orientation, with the pinion pointing forward)
turn the rear drive yoke counterclockwise as viewed from the rear of the truck. *which also means clockwise if viewed from the transfer case end.

the rear axle will pull the truck forward. *(or PUSH, depending on your view, however skewed.)


In other words, you installed the rearmost drive axle assembly backwards.








NIIIIIIIICE!

[lapeer20m]

Originally Posted by imadumass

Oh, boy.....


In other words, you installed the rearmost drive axle assembly backwards.

NIIIIIIIICE!

if both the front and rear driveshafts spin in the same direction ie: clockwise, then the rear axle assembly is installed correctly

here's a beautiful hand drawing showing the current axle configuration looking from the top down

[lapeer20m]

i'm at work today for 24 hours so i can't go check out my truck and see
about the T-case. GRRRR!


As luck would have it, i found a guy with a 4wd suburban. I layed down
next to it while he drove a foot or two and i now have the definitive
answer.........




My axle configuration is correct. Both front and rear drive shafts spin in
the same direction. I had talked to several junk yard guys when i was starting the project and had discussed axle orientation with them, and not a single one suggested I was incorrect.

another disaster averted lol

[paul iossi]

Why can't you use a divorced chain transfercase from something like a F350 and use a U joint @ pinion/tcase and shorten the driveshaft to fit. I don't think that the tcase will know that it is being driven backwards.

[paul iossi]

Oops, the different axle ratio thing, stagger the tire sizes front to rear keeping in mind that the front needs to pull harder than the rear to maintain steering and that any small ratio differential will be taken care of by tire slippage @ the rear/light end. A perfect match isn,t necessary as long as you stay off of hard surfaces and or don't lock the axles up solid (lincoln locker).

[the_experience03]

Actually...you bot hare right. Obviously it will turn the correct direction the way you have it mounted, but had to turned it around it would have worked equally as well. The ring gear to pinion gear interface would have actually been a little strong had you turned it around because you wouldn't have been driving on the coast side of the gears, but that's really neither here nor there at this point.

The driveshafts do spin in the dame direction, but as far as the differential is concerned, it spins the front pinion counterclockwise and the rear pinion clockwise. This means that they would be driving in opposite directions, right? Well no because the pinions are oriented opposite each other so being driven in different directions makes them travel overall in the same direction. You run into problems when you physically flip the axle over. That's why there are reverse rotation gears for high pinion front ends. Again....it's already welded so where do you go from here?

Either way, the torsion bars weren't going to work. I'm interested to see how you plan to attach those air shocks. They can't go on the lower control arms because of the CV shaft and they really shouldn't go on those cheesey upper control arms. In the GM IFS design, the upper control arm is simply meant to control camber. The lower control arm takes the weight of the vehicle.

That pinion sprocket is going to be a REAL p.i.t.a. to do correctly. Your plan for centering it seems to be just fine, but I question how you're actually going to attach it. Welding to that cast iron yoke is going to be a treat. I fear it might break regardless of how well you weld it. Bolting is another option, but you sure don't have much contact area considering the bolts would be in single shear. My driveshafts on my Toyota use 4 bolts in single shear, but they are centered by a nose on the driveshaft campanion flange that fits into the companion flange on the pinion. The flanges are full circle and contact each other for the entire 4 inch or so diameter. That means that the bolts provide the clamping force so that friction is what drives it. The bolts themselves do not take up any of the torsional load. I actually proved this as a trail fix one day when I managed to knock the heads off 2 of the bolts on a rock. I just put the remaining bolts opposite each other and c-clamped the flanges together where the two missing bolts would have been. It held all day and let me tell you....if anything was going to break those other two bolts due to torsional loading, it would have been that trip.

So....figure out a REALLY good way to attach that sprocket to the pinion or get out the cutting torch, turn that differential around, and run a driveshaft.

[lapeer20m]

Originally Posted by paul iossi

Why can't you use a divorced chain transfercase from something like a F350 and use a U joint @ pinion/tcase and shorten the driveshaft to fit. I don't think that the tcase will know that it is being driven backwards.

that would work great.....except i don't have one laying around.

Actually...you bot hare right. Obviously it will turn the correct direction the way you have it mounted, but had to turned it around it would have worked equally as well

I disagree. If the yoke were turned toward the front of the vehicle it would be spinning the opposite direction. Even the experts at the junk yard agree with me on this point.

as far as the air shocks, why can't they be installed where the old shocks were mounted? The mounting brackets may need to be beefed up a bit, as the stock ones are not really designed for much load. May have to adapt a bit as there are no air shocks available for the front end of vehicles...not at autozone at least.

[paul iossi]

New sprockets and chain aren't inexpensive even with an inside source and bone yard chain t-cases are abundant, you also solve the sprocket to pinion and driveshaft attachment dilemma.

[the_experience03]

Relative to the pinion's position, the driveshafts spin in opposite directions. I know they are both spinning counterclockwise if you're facing forward, but in reality, they are spinning the differentials in opposite directions.

Let's put it like this...the way you have it set up, the pinion will spin counterclockwise and the truck will go forward. If you turned it around, the pinion (when facing it) would turn clockwise so it would drive the axles backwards...but that's fine given the fact that the differential is now also backwards. I know it's hard to visualize, but I promise it's true. If you ever look at rigs with rear steer and solid axles, you'll see that they just took a front axle and put it in the back. They didn't flip it, they don't run reverse rotation gears (unless it was high pinion to begin with), and they don't run a chain drive. You're perfectly right that it will go the correct direction the way it is, but I promise it would also work turned around.

As for the air shocks...did the old shocks attach to the lower control arm? If so theyn you're fine. If they attached to the upper control arm, I might question putting that kind of load on it. You might no break anything right away, but it will take it's toll. Shocks, afterall, don't cary any of the weight of the vehicle. They simply dampen the harmonics of the springs.

[the_experience03]

Originally Posted by paul iossi

Why can't you use a divorced chain transfercase from something like a F350 and use a U joint @ pinion/tcase and shorten the driveshaft to fit. I don't think that the tcase will know that it is being driven backwards.

The t-case will know when the input becomes the output and the output the input. The output becoming the input would be fine, but the input becoming the output will run you into some trouble. The shaft diameter along with the bearings are not designed for the torque multiplication. What divorced chain driven t-case are you referring to? The only one that comes to mind is an NP203 (which you shouldn't have to pay more than scrap for. )

The general rule I've always heard for front to rear differences is 2% with the rear being over driven and 3% with the front being overdriven. That's close enough that you wouldn't even notice, locker or not, as long as you weren't doing figure eights on dry pavement. Unfortunately, 4.10 versus 3.73 is an almost 10% difference.

[imadumass]

So, the nice way didnt work. Lets explain this so even a dummy can see the logic...

Gee, all those manufacturers that have been making axles for all those years couldnt be wrong, could they? damn the luck... I wonder why thier stuff doesnt work?

Please, see the light. Wipe the turds out of your eyes and reverse the orientation of the rear most installed driven device you call an axle. it will save lives, you know. maybe even yours. dont just turn it over, because that will reverse it. disassemble it, change the orientation, and put it back together.

and dont try to tell me that what you have done will work. while it may work in theory, youre throwing good money after bad trying to hackmeister flash something together.

What you are attempting to do is simply ignorant. if you want to be innnovative, build a time machine, and go back 100 years. Otherwise, stick to driving busses. Please dont modify them too much, because your skills are severly lacking.

[captainkf]

Excuse me, IMADUMASS, but there is no need to take that kind of tone here. You can disagree with him, then you must let it go. It's his truck, not yours. Don't be so rude. It's not nessisary. Relax or mabye you need to take a time out and go play by yourself until you can be nice to others.

-Richard

[imadumass]

Originally Posted by captainkf

Excuse me, IMADUMASS, but there is no need to take that kind of tone here. You can disagree with him, then you must let it go. It's his truck, not yours. Don't be so rude. It's not nessisary. Relax or mabye you need to take a time out and go play by yourself until you can be nice to others.

-Richard

Dear sir, please understand that my intent is to inform. Unfortuneately, the gentleman has not yet learned to listen to the voices of reason that have been lecturing him.

Why, you ask? Certainly someone will hop into his machine, and go for a test ride with him. Im sure he would be overwhelmed with grief when he finds that he built a machine that put his friend in the hospital.

Of course, thats the negative side of this equation. I am not focusing on the negative. I am hoping to prevent that by inserting some common sense prior to the accident. Surely you understand that, and can agree.

Now, if you condone someone building a vehicle that you find "unsafe at any speed" (to quote a guy about a corvair) you could sit casually by and let nature take its course, and natural selection win out. At this point, I just want to watch the video of the actual carnage as it takes place.


Oh, dont forget to have someone with a strong stomach video tape the first test run and post it on here.



Am I being sarcastic? yes. Am I being honest? yes. Is that Illegal?

This is the internet. Honesty is a brutal thing, sometimes. If I have offended, I apologize. If I have saved a life, be only grateful to the person that reads and understands the dangers inherent in modifying a vehicle improperly.

If you think I am giving this guy grief just to give him grief, Please listen to reason and stop anyone that is doing this type of modification in the name of advancement of the human race, or even recreation. Theres a reason they hire engineers.

as far as being rude goes, please dont get me wrong on this one but......

There are a lot of brilliant minds here.

Why *(in gods name, WHY?) has no one else stepped up to ask him why he is building something so inherently dangerous? Afraid to offend? scared that someone might call you RUDE? Sure, Ill relax. I wasnt excited in the first place.

Take it or leave it. By the way, if this post gets deleted, we will all know that this forum is too scared of being politically correct to actually call someone on bad judgement.

Thank you for your time.