Poly 318, NP205, Dana 70 axles.

[Jonas Smith]

Just so you guys dont think I've been sitting on my butt all holiday season... I am making progress on the Poly 318 Truck. I have the Dana 70 axles installed, and the Poly 318 w/NP420 is mounted. I have the 205 transfer case mocked up. and just need to get all my drive line angles squared away before bolting everything down. After much deliberation I think the way to go is going to be a Helitool hanging pedal and power steering kit. Heres a picture of the 205 with Spicer PTO installed.



Heres a link to the photo album:

http://ImageEvent.com/rockinjwranch/...polypowerwagon

[Kevin Mienke]

We all know how busy you've been.

[Deathdeelr]

Nice project. Can I ask about the hub adapters? Are you just looking for extra track width or are you hanging a completely different wheel? I can't really tell from the pic if the bolt patterns are the same. Custom spacer or commercially available?

[Jonas Smith]

Nice project. Can I ask about the hub adapters? Are you just looking for extra track width or are you hanging a completely different wheel? I can't really tell from the pic if the bolt patterns are the same. Custom spacer or commercially available?

I made those myself, well I should say that I had to have them machined on a lathe also. Single rear wheel W300 used the same type of adapter, to get rear wheels to track in line with the front wheels. They are just harder than hens teeth to come up with. The early 6 lug D70 rear is narrow for the installation of dual rear wheels.

[MoparNorm]

Nice Headers...for what you paid for them you could have at least plugged the source...ha !ha !ha!

[odog]

Interesting

Interesting project. What are you going to do with it? I have to ask why use the closed knuckle dana 70? Seems like a lot of work for minimum gain. Still run tracta joints (I think), still closed knuckle, no disc brakes (unless converted more $$), parts are harder to find than PW stock axles, minimal strength gain compare to a more modern axle (I think 21 splines?), heavier, and less ground clearance. Old school wheels are cool but you are already machining parts. Maybe I am missing the point, not trying to be a stick in the mud, just asking?

[Jonas Smith]

Interesting project. What are you going to do with it? I have to ask why use the closed knuckle dana 70? Seems like a lot of work for minimum gain. Still run tracta joints (I think), still closed knuckle, no disc brakes (unless converted more $$), parts are harder to find than PW stock axles, minimal strength gain compare to a more modern axle (I think 21 splines?), heavier, and less ground clearance. Old school wheels are cool but you are already machining parts. Maybe I am missing the point, not trying to be a stick in the mud, just asking?

Because I already have all the parts from wrecked trucks that i've parted out. D70's are way cooler than the modern axles with 8 lug wheels IMHO. True it would be much easier to put the body on a blazer or surburban chassis, but I like using the old timey stuff.

I'm building a 1925 Graham speedster with a Chrysler straight 8 out of a 1946 industrial generator. I'm using all parts to build it from pre-'49 vehicles. Would it be easier to use a 440 and more modern stuff, sure... but it misses the point.

Oh yea, those fabulous headars are DTA poly headers. Available from Norm.

[Deathdeelr]

I'm building a 1925 Graham speedster with a Chrysler straight 8 out of a 1946 industrial generator. I'm using all parts to build it from pre-'49 vehicles. Would it be easier to use a 440 and more modern stuff, sure... but it misses the point.

We're going to need to see some pictures of that.

PLEASE!!!! I NEED TO SEE SOME PICTURES!!!!

Sorry, sometimes I lose my composure during these discussions.

[Jonas Smith]

Setting driveline angles....

Front motor mount and radiator installed (well, mocked up) last night. Take note of the decked DTA Poly headders from Norm that was the ballywick for building this truck in the first place. ;-))




Working on setting driveline angles today. The front axle is way off.

Heres what I have for angles now:

Transmission output yoke- 92 Deg
Transfer case Input Yoke- 93.5 deg
Transfer Case output yoke to front- 93.5 deg
Transfer case output yoke to rear- 93 deg
Front axle yoke- 84 deg YIKES!
Rear axle yoke- 80 deg

No big deal on the rear axle because I havent welded the spring perches in place. I can rotate the whole axle assy to get a 93 deg angle which seems about right. But what about the front axle? Wedge shaped shims on top of the axle and under the springs?



http://photos.imageevent.com/rockinj...ront%20010.jpg

[712edf]

I believe a company called Dedenbear has to capability to take a front axle housing, remove the diff housing from the axle tubes, twist the tubes, then reconnect everything. The result is that your differential yoke is at the angle you want, but the spring perches still have the same relation with the springs & the kingpins still have the same relation (caster) with the ground.

While wedge shaped shims will give you the desired differential angle, caster will be affected as well.

Bucky

[Deathdeelr]

While wedge shaped shims will give you the desired differential angle, caster will be affected as well.

Measure the caster angle before you go down this road. You're going to need a caster angle of over 10 degrees before I'd say wedges would be worth the effort and I doubt you have more than 3 degrees in the axle as it sits now. Most trucks I've had on the alignment rack are anywhere from 2 to 7 degrees negative which still means you'd need an 8 to 10 degree wedge on the spring perch. If your final caster angle is less than 2 degrees you may end up with a truck that wears out your arms over 30 mph (the truck will wander all over the place). I'd agree with 712 and say find someone like Dedenbear (actually Reid Racing for off road stuff) to reangle the differential housing. You may end up saving money over trying to correct the angle using other methods.

To simplify:

Front transfer case yoke 93.5 minus front axle yoke 84 = 9.5 degrees of correction.

If you want a final caster angle of 2 degrees minimum then you are hoping for an initial measurement (what the caster angle is right now) of 11.5 degrees.

As I said before I don't think you have anything close.

[Jonas Smith]

You mean over 10 degerees caster on the knuckles from perfectly level? Hmmm. So what you are saying is that the front axle needs to be rotated forward? The way I'm taking my measurements. perfectly straight up and down would read 90 degerees on my protractor. So I need to figure out a way to have my yoke set at 87 deg. right? The transfer case yoke is tipped up 3 deg. from perfectly straight up and down, so would in not make sense to have the front pinion tipped down 3 deg. to balance the angles out?

[Deathdeelr]

I think I completely misunderstood where you were taking your angles from. Yes, to have the same angles you'd have to tip it down 3 degrees. You should have no problems locating a set of 3 degree wedges at any good 4wd shop. Probably run about $20 for the pair. This will increase the negative caster on the axle which will actually make the truck more stable at higher speeds but might make the turning radius slightly wider. Either way you're not going to do any damage at all. Make sure you double check/adjust the toe in when you're done.

If you went the way I was going with the way you're measuring you'd have a drive shaft curving up through your oil pan. Oops...

At least you wouldn't have to worry about hitting it on anything!

[Jonas Smith]

I think I'm in luck...

I measured the caster on the D 70 front axle the way it sits right now. I measured across the 4 bolts that hold the top kingpin bearing in. It measures 2.5 degrees tipped forward. My various WDX style Power wagons all measure about .5 degeree tipped forward.

So with the transfer case tipped up at +3.5 deg from center (93.5 deg reading on protractor),

and the front axle yoke tipped up 5 Deg. from center (85 deg reading on protractor),

That would me I am out from perfect driveline angle by only 1.5 deg right?

[712edf]

its been 27yrs since I had geometry class

Here is what I am interpreting.

Your front t-case output is pointed up 3 1/2 degrees above horizontal.
Your front differential yoke (centerline of pinion gear) is pointed up 5 degrees above horizontal.

Since they are facing each other, wouldn't that mean the axis(pl) of their centerlines form an 8 1/2 degree angle?

I am certainly NO expert in either drivelines or geometry, but my elementary thinking leads me to believe that the t-case must be mounted so that both outputs (and the input, which is fixed parallel to both) are perfectly horizontal. Tipping the t-case up in the front may help minimize the rear driveshaft u-joint angles, yet it worsens the front drive shaft u-joint angles.

Bucky