'90 K5 - The Nevada Blazer [Post 1437: School me on alternators)

[colbystephens]

What post number is a picture of it

I'll find a pic for ya.

How about a non cv shaft with 1410s? They have a pretty decent operating angel

I wondered about that too. But, I'd hate to go that route now because I've already purchased a new 1350 yoke and had this driveline built.

The problem he's running into is that the NP208 CV drivelines are designed with very little operating angle. They have built in "ears" even to keep them from moving much in angle.

Colby did grind those ears some for more clearance. Comparing it to a NP205 driveline, the NP205 has far more room built into the CV area for movement (operating angle).

I got rid of those ears, and ground down everything I could. I think what's happening is I'm hitting the cup of the ball-socket deal against the surface of the CV. FWIW, I have a 241. I doubt that makes much difference in the conversation though.

Guess it might be time to get rid of the 208 drive shaft, I thought it was a custom one that he was having all these problems with.

You are right - kinda. It's a modified stock shaft.

I'm still thinking that adding an inch or two of lift to the rear of the truck might be a good solution. It would tilt the front output forward. As the rear is lower than the front, it is making an already up-ward-facing output face farther up. What do you guys think about this?

 

[kgblazerfive]

How much work and cost would that be vs. just having a new front drive shaft made.

 

[y5mgisi]

I'm confused as to how lifting the rear of the truck will effect operating angles on the front drive shaft?

Edit: I think i get what your thinking. Your thinking that the rear of the truck being lifted will point the front out put on the t case more toward the ground and therefore more towards the axle. That it will do. But in doing so, your front pinion will point more away from the ground due to the fact that your fulcrum in this scenario is where the front tires meet the road or your front axle center line depending on how you think about it. One way or another the front tcase output and front pinion angle will always correlate no matter how much you lift the rear giving you the same effective operating angle on the u joints despite the fact that the shaft is now at a different angle.

 

[Smokinthehippies]

much as i hate to say it.
what about getting one of those 1" transfer case drop setups. (basically four spacers that kick the crossmember down).
i think the ground lost at the t case might be better then the binding at the yoke. besides it would be a cheap temp option until you could decide to do a new front shaft.

 

[MTBLAZER89]

The transfer case drop "kits" only help the angle for the rear driveshaft. It will actually make the angles for the front worse.

Colby is it binding at the pinion or the CV? I know you went to a 1350 which has less angle capability than the original 1310 is why I ask. I am not sure which yoke you went with, but I know they make some "deeper ones that allow for a bit more angle. Also if it is at the pinion one of those offset u-joints will give you a few more degrees as well.

If it is the CV unfortunately you are sorta stuck as you can only make it so much better. I am not sure which shafts I am using, but they are stock CVs that are clearanced the way you did it with a 1310 joint at the pinion. I have had more issues with my pinion joint binding than the CV.

 

[colbystephens]

It's the CV.

 

[y5mgisi]

I know when I clearnced mine, it was a 1310 so maybe that does make a difference, but i just kept on clearancing until I could flex it out, and still spin the front driveline by hand. There was some loading docs near by and i just flexed out on them until i got a tire to lift(in 2wd) and then crawled under it and gave the shaft a spin. First and second attempts left me with the shaft fully bound so it wouldnt spin. Third time was the charm tho. Flexed out all the way and the shaft still spun freely. Before i clearnced it the thing wouldn't even bolt up! This was on a standard old school style lift. Just springs. No degree shims, longer shackles, zero rates, etc.

 

[Smokinthehippies]

The transfer case drop "kits" only help the angle for the rear driveshaft. It will actually make the angles for the front worse.

Colby is it binding at the pinion or the CV? I know you went to a 1350 which has less angle capability than the original 1310 is why I ask. I am not sure which yoke you went with, but I know they make some "deeper ones that allow for a bit more angle. Also if it is at the pinion one of those offset u-joints will give you a few more degrees as well.

If it is the CV unfortunately you are sorta stuck as you can only make it so much better. I am not sure which shafts I am using, but they are stock CVs that are clearanced the way you did it with a 1310 joint at the pinion. I have had more issues with my pinion joint binding than the CV.

really?
if it drops the whole of the t case down how would it not help the front?
what am i not seeing here for that to make sense?

 

[hunterguy86]

really?
if it drops the whole of the t case down how would it not help the front?
what am i not seeing here for that to make sense?

I'm picturing this in my head so bear with me. Only the back of the tcase really moves down since it's bolted to the transmission, thus increasing the angle at the front.

 

[Smokinthehippies]

I'm picturing this in my head so bear with me. Only the back of the tcase really moves down since it's bolted to the transmission, thus increasing the angle at the front.

But wouldnt the tranny drop down as well. yes the angle would increase, but the t case output and the pinion would be closer to level so wouldnt that take some of the edge off?

 

[Richcz28]

Dropping the cross member causes the front output of the t-case to drop down, but it will be angled more upward. It doesn't drop down straight, because the engine is attached to the mounts. It really just leans everything back. This seems to be when his drive line is having the most problems, like going up a hill.

At least that's how my brain is picturing it...

 

[colbystephens]

Dropping the cross member causes the front output of the t-case to drop down, but it will be angled more upward. It doesn't drop down straight, because the engine is attached to the mounts. It really just leans everything back. This seems to be when his drive line is having the most problems, like going up a hill.

At least that's how my brain is picturing it...

Yep, this is correct. If you picture the engine as the fulcrum, the tail end is going to drop. Apparently the angle of the driveline already causes the front output to point slightly upward. One person suggested to me that I could try raising the transmission a touch to rotate that output to a more level position. This is kind of what I was imagining by lifting the rear of the truck.

 

[Smokinthehippies]

Dropping the cross member causes the front output of the t-case to drop down, but it will be angled more upward. It doesn't drop down straight, because the engine is attached to the mounts. It really just leans everything back. This seems to be when his drive line is having the most problems, like going up a hill.

At least that's how my brain is picturing it...

ok. thats how i was pictureing it as well. i guess i figured the drop down would offset the angle up. but i ugess not enough.

carry on.

 

[Richcz28]

sorry if this was asked before, but you have a long thread. How are your tranny mounts? Could you be getting some sag and vibration from old rubber mounts?

 

[colbystephens]

It is possible. I did get under there a few weeks back and found that the mounting bolts were loose. I tightened them up, and that helped some. They are likely the stock mounts from 1990.

 

[Richcz28]

Even if they don't fix the problem new mounts may help mask it somewhat.

 

[MTBLAZER89]

Y a know I did just think of this. My CV used to rub on my crossmember under a lot of torque. I did take a piece of bar stock 3/8" IIRC and drill it for a T/C spacer between the foot and the mounts. It has been in there for years. Maybe that tiny bit would help.

Its still weird to me how some people have no issues and others cant make the same setup work. I have a TH350/241 and a ton of downtravel and I dont have any issues with my CV. My pinion joint is what I worry about.

Other than a small spacer, a new 1410-1410 shaft, or a new CV I can't think of a solution.

 

[82K10SBC]

With a 4" lift and 35s my np208's angle made my cv regrind my crossmember. Havent tried mine since it for 8 more inches of lift though. Ive heard of some guys building spacers off the flange on the case to push the cv further away from the x-member....

 

[colbystephens]

Y a know I did just think of this. My CV used to rub on my crossmember under a lot of torque. I did take a piece of bar stock 3/8" IIRC and drill it for a T/C spacer between the foot and the mounts. It has been in there for years. Maybe that tiny bit would help.

Its still weird to me how some people have no issues and others cant make the same setup work. I have a TH350/241 and a ton of downtravel and I dont have any issues with my CV. My pinion joint is what I worry about.

Other than a small spacer, a new 1410-1410 shaft, or a new CV I can't think of a solution.

Hmmm. I might have to check out the possibility of a spacer like that.

With a 4" lift and 35s my np208's angle made my cv regrind my crossmember. Havent tried mine since it for 8 more inches of lift though. Ive heard of some guys building spacers off the flange on the case to push the cv further away from the x-member....

Strange, I had a 4" lift, 700/208 once w/ 35s (tires don't really matter, I guess), and it didn't grind/rub/whatever.

I think what I better do is flex the truck out, driver's side high - passenger side low, park it, unlock the hubs, and spin the d-shaft by hand and see what's going on. Thanks for the suggestion, Mitch!

 

[y5mgisi]

You bet! Just be very careful! Common sense will keep you from letting your truck run over you! THats why i like the loading docks. They were the kind that went below the level of the rest of the parking lot area so once you were all flexed out the truck really didnt want to roll either direction. I could have had it in neutral and been fine but none the less, it was park, with parking brake, truck off, and give it the "earthquake test".