Need driveline opinions...

[Mastiff]

14-bolt is in place now, where a 12-bolt used to be. I have a CV driveshaft. When I had the perches moved for the swap, I had the guy tilt them so the driveshaft would supposedly point at the T-case so I wouldn't need shims like I had before. The guy acted like he'd done it many times before and knew exactly what to do.

To me it looks like a lot of angle at the pinion for this kind of setup. Best I can estimate with my little angle-ometer, the pinion is at 10 degrees, driveshaft at 25, and t-case output at 5 (all relative of course). Getting a good measure of pinion is tough. It also looks to me like I have a lot of slip yoke sticking out of the 208. It's hard to believe it could ever compress enough to use that up. If anything I expected the bigger 14-bolt to start closer than the 12 though.

What do you guys think? Should I shim it? Does the slip yoke look right for flat and level? I'd love to eliminate the slip yoke altogether and reclaim that length. Is there any easy-ish way to do that on a 208?

 

[Avery4jc]

Where did you get that drive shaft? If all you did was swap in a 14 bolt it shouldn't be that short.
What else did you change during this swap? Springs? Maybe you put them in backwards.

Pinion angle looks off in that pic too. Needs to go up more.

 

[nvrenuf]

The pinion and the driveshaft need to be at almost the same angle. Iirc, most folks set the pinion 2° down from the driveshaft.

 

[Mastiff]

Where did you get that drive shaft? If all you did was swap in a 14 bolt it shouldn't be that short.
What else did you change during this swap? Springs? Maybe you put them in backwards.

Pinion angle looks off in that pic too. Needs to go up more.

New ORD springs too. Same lift supposedly, though the old ones may have settled some. Backwards? It's possible I guess. I put the military wrap forward, not sure it could even fit in the shackle. How could I tell if they were backwards?

 

[nvrenuf]

are they 52 or 56?

 

[Avery4jc]

Custom alcan ord springs? You could measure your old springs end to center pin and compare to the new ones.

 

[Mastiff]

Custom alcan ord springs? You could measure your old springs end to center pin and compare to the new ones.

Yes. Good idea, I'll check against the old springs.

Right now I have new ORDs in the back and old Rancho's on the front. Measuring axle center to the body seam, it's two inches higher in the back. If that's a reliable way to measure, and if my fronts are 4" lift, the new springs are 6" lift. I actually asked for 4.5". Maybe the new springs need to settle, and/or the old ones have flattened a bit.

The driveline angle isn't helped by extra lift, or by the short driveshaft sticking out too far...

 

[drivelineman]

Get the pinion 2 degree's down in relation to the shaft angle - and retube the shaft , the problem with the c/v you have is its not splined all the way . Jess

 

[Mastiff]

Get the pinion 2 degree's down in relation to the shaft angle - and retube the shaft , the problem with the c/v you have is its not splined all the way . Jess

What do you mean not splined all the way?

I know that I want the pinion almost aligned with the driveshaft, but I'm really confused about how it got this way when nothing really should have changed much. Lift is supposed to be the same, and 14 vs. 12 bolt measures about the same from tube to yoke.

Just shimming the axle isn't the right answer since the shaft now appears too short. If the slip was further into the t-case, the angle wouldn't be as bad.

 

[Blue85]

Is that the cadillac C/V?

There are a few options to get rid of the slip yoke you can search on:
-Dodge/Chevy hybrid case
-Tom Woods SYE
-Bolt-on flange (drill and tap the output shaft)
-Swap to a 241, for which a normal SYE is available

I don't think that C/V you have is compatible with any of the above.

 

[Mastiff]

Is that the cadillac C/V?

There are a few options to get rid of the slip yoke you can search on:
-Dodge/Chevy hybrid case
-Tom Woods SYE
-Bolt-on flange (drill and tap the output shaft)
-Swap to a 241, for which a normal SYE is available

I don't think that C/V you have is compatible with any of the above.

I had that CV custom made by Tom Woods or whatever it was called 15 years ago. It fit properly before the ORD springs/14bff comversion. Looking at the slip yoke, it looks like I lost about 1.75" in this conversion. I'm totally confused really. I wonder if ORD sent me springs that move the axle back by mistake? I don't know how to tell. Simple tape measure measurements show about 26" eye to centerbolt on the new springs and 25" on my old ones (both 4" lift). Both symmetric.

Tom Woods seems to have the 208 SYE: http://www.4xshaft.com/SYE/208TransferCaseGMDesign-32Spline.html

Kind of pricey, but I fear there's a new driveshaft in my future anyway. I really want to avoid shims to get the driveline right.

 

[paratrooper307]

I had that CV custom made by Tom Woods or whatever it was called 15 years ago. It fit properly before the ORD springs/14bff comversion. Looking at the slip yoke, it looks like I lost about 1.75" in this conversion. I'm totally confused really. I wonder if ORD sent me springs that move the axle back by mistake? I don't know how to tell. Simple tape measure measurements show about 26" eye to centerbolt on the new springs and 25" on my old ones (both 4" lift). Both symmetric.

Tom Woods seems to have the 208 SYE: http://www.4xshaft.com/SYE/208TransferCaseGMDesign-32Spline.html

Kind of pricey, but I fear there's a new driveshaft in my future anyway. I really want to avoid shims to get the driveline right.

If that shaft is in good condition, just have it lengthened, it would be cheaper than getting a new one. And as others have said, that pinion angle looks pretty far off. Yes, it has to point at the TC, but the shaft and pinion need to be at approximately the same slope. Most people set the pinion 2 degrees down to account for axle wrap when at part throttle.

I'd just have that person fix the perches. once you get the right length for the shaft, they obviously weren't set right.

 

[Mastiff]

Any idea why the shaft is suddenly the wrong length? Nothing should have changed that I can think of.

 

[paratrooper307]

Any idea why the shaft is suddenly the wrong length? Nothing should have changed that I can think of.

The only possible culprits are the springs and the axle. The axle causes very minor change in the distance but shouldn't be enough to worry about. The length of the spring/level of lift is what is going to make the difference, assuming you haven't moved the axle forward or backward.

I lifted mine 4" in the back, and the factory shaft was still serviceable, albeit sticking out more than I liked, so I went ahead and measured for a new CV shaft. It would seems that your springs are too long/have too much lift.

 

[rebelgregory]

Yeah. I'm leaning towards something with the springs.

I also swapped from a 12bolt to a 14 with the same CV shaft and adapter joint. However, I also used the same rear suspension setup. I used spring perches and U-bolt plates from WFO that allowed me to move the axle 1" back (you can see the holes in the plate). This let me use the same shaft while allowing for longer 14 bolt pinion housing.

I made my pinion angle adjustment at the perches before welding them in. A good way I found to get the pinion angle was to take your output and driveshaft measurements, then remove the U-joint straps at the axle and take a vertical measurement on the yoke surface (across the 2 strap holes). Add or subtract 90 deg to get an accurate horizontal measurement.

Here's mine set at 1.5 deg down.

 

[Mastiff]

We installed the front ORD springs today and stuff looks wrong up there too.

This pic is with weight on the springs. The driveshaft is laying on the exhaust pipe and there's no way it could connect. The second pic shows that the perches appear angled back relative to level ground. This is a D60 with no mods to the perches or anything. It doesn't seem right to me. Also, the center pin on these springs is not in the center like the old springs were. It's like the axles are attached to the part of the spring that is already sloping up to meet the front hanger.

I'm going to double post this into the ORD section.

 

[Deuling]

It's easy. You put custom parts on. You need to make changes everywhere else.

Just the way this stuff tends to work.


So fix your angles, get your driveshafts to fit, and go play.

 

[Mastiff]

So fix your angles, get your driveshafts to fit, and go play.

You said 5 degree shims fixed yours? I think the way it is now I need about 10 on the front and more than that on the rear. That doesn't seem right for a 4" lift.

If it was just a matter of a few normal shims and lengthening a shaft, I agree that's no big deal. I need to talk to ORD and see what they think is going on before I do anything.

 

[rebelgregory]

Before you get carried away on the front, don't go shimming until you can get the u-joint bolted up. It's more important that your caster angle is right. The imaginary line that runs vertically through the axle 'C' at the kingpin. Can't remember exactly, but 6-8 degrees is what I have in my head. In other words, the kingpin needs to be towards the rear of the truck compared to the lower trunion. Deah wobble and seriously scary steering can result if it's wrong.

It's not at all uncommon for front driveshaft to hit the y-pipe after a lift. Usually requires exhaust modification, not axle modification. Mine hit with 4" springs. I went to headers and true duals, but that was 10 yrs ago.

You may already know all this, but if not and there's nothing wrong with your front caster angle, axle shimming will just cause headaches down the road.

 

[Mastiff]

I had 4" lift before I put these springs on and it cleared the pipe fine. Previously I sort of split the difference with the shims. Didn't aim it right at the transfer case, but angled it up a little. I had maybe 2 degree shims in there.

But thanks for reminding me. 10 degrees is what I'd need to get it within a few degrees of directly aligned with the driveshaft.

The thing that I can't understand is why it's so different now.