Front Drive Shaft Universal Joint exploded (pics)

[mpierce9]

I believe this is an NP203 transfer case. It's in a 1975 Blazer with full time 4x4 and auto locking hubs. Gear shifter only allows:

• 4 Low Loc
• 4 Low
• Neutral
• 4 High
• 4 High Loc

I'm trying to figure out what I need to purchase to repair this. The rear section of my front drive shaft, what i believe is called the Double Cardan joint had one of the universal joints pretty much just get ripped to shreds recently. I removed the driveshaft as well as the double careen joint in order to make the truck drivable without anything beating around.

Outside of some surface abrasions the drive shaft appears to be in good condition. The front universal joint and linkage also appear to be in good condition. I believe (I may get these part names wrong) the ball stud yoke and one of the universal joints is in need of being replaced as well as possibly the Carden joint yoke. I want to make sure I get the right parts the first time. I'm hopeful my driveshaft does not need replacing.

Please feel free to correct any of my assumptions and provide any guidance. I have zero experience doing any of this. I also realize that I need to replace my auto hubs with manual locking hubs at some point in the future.

Double Carden joint still attached to the transfer case with the driveshaft removed. Easily seen in this and the next image is where the universal joint previously sat. The fragments still remain.



Close up of the Double Carden joint specifically the front facing portion of the ball stud yoke.



One last really close up of the ball stud yoke portion of the Double Cardan joint.



A wider shot of the Double Cardan joint not focusing on the yoke. You can see on the right end the universal joint which seems in good condition.



The remains of the universal joint that got beat to death.



Rear end of the driveshaft that connected to the Double Cardan joint and the destroyed universal joint.



Same thing, just a wider shot.



An overall picture of the entire mess of items.

[cadillac_al]

Any drive shaft shop can fix that quickly. I never mess with them myself. You could probably find a used driveshaft if you have an old junkyard close by.

[TheBlueBomber]

^What he said. I would take it to a local driveline shop and see if it's reusable.

[mrolds88]

I would check with the driveline shop too. Looks to me like the pin is bent on the end of the shaft. also check craigslist and junkyards for another shaft. Might be the cheapest route.

[Desert1957]

There is evidence in your pics of a "Dry" bearing cup on this joint, when this happens , the joint will lock up and break. Everything else it connected to can be torn up in the process.

Desert

[imjeff]

Driveshaft is junk. Make sure your yokes on the t-case and front diff are ok, get either a wrecking yard driveshaft of have yours repaired and balanced. Convert to part time 4wd.

[Willowrun]

Originally Posted by imjeff

Driveshaft is junk. Make sure your yokes on the t-case and front diff are ok, get either a wrecking yard driveshaft of have yours repaired and balanced. Convert to part time 4wd.

I'm going to agree with Jeff...that Driveshaft is junk. I'm interested to hear what the shop says because all of the components that need to be replaced, plus u-joints, plus labor will be getting close to $200. That price is approaching the cost of a reman which is around $300. The $200 won't address your slip yolk either which I'm sure is sloppy.
I've needed to replace the front driveshafts on several of my trucks and here is what I found to be the most economical and effective:
Go to the junkyard and find an XJ Jeep Cherokee that is '88 or newer. Most XJ's are not full time 4wd and they are very plentiful in junk yards now. Grab onto it to check for play in the cardan and slip yolk before you pull it. Upon finding a good one pull it ( In the 4-5 I've pulled they all seem like new compared to the wore out Chevy shaft). Should be $20-$30 to buy from the yard. Now take your old shaft and the xj shaft to the driveshaft shop. It will need to be shortened 3-4 inches, balanced, and the t-case flange will need to be added. Should cost $100-$120 all said and done for a basically new driveshaft.

[bnoon]

Wow, that did pretty much grenade out of there! Wasn't there a bad ping and slop going between gears??? Having a duh moment? I know I had one when I finally pulled my drive shaft a few months ago and found missing needle bearings (like yours shows evidence of). I caught mine in time though luckily for me. I'd go the salvage yard route, but I am biased because I go there just about every Saturday morning anyway. Good luck!!!

[mpierce9]

I'll be taking this to a driveline shop in the Atlanta area. I called them today. I'm anxious to see what price tag they recommend. In the meantime the truck drives fine. I prefer to leave the front drives shaft out for gas mileage and I don't take it off road. I want to have the drive shaft repaired in case I decided to sell. Is there any reason for me to reinstall this after I get it repaired? Are there further steps I can take to cause the transfer case to not propel this drive shaft? I'm going to sling a little grease on the main drive shaft to make sure it doesn't suffer the same fate.

[andrewmp6]

They sell a kit that changes your full time t case to a part time t case.

[hatzie]

Since she is driving without the front shaft I would bet you have a part-time kit already installed or your're running in 4 HI LOC.

That shaft is spent. If the slip yoke is loose then it's scrap metal.

A decent driveshaft shop will be able to build you a GM front shaft from a salvaged Jeep XJ chassis front driveshaft.
While you're at it... get the steering box to column shaft out of an XJ and upgrade from the rag joint to a universal joint steering shaft.

[imjeff]

Originally Posted by hatzie

Since she is driving without the front shaft I would bet you have a part-time kit already installed or your're running in 4 HI LOC

The rear drive shaft always spins. The truck drives without the front shaft because the rear wheels are driven and the front shaft yoke is free to spin. Part time kits disengage the front axles at the hub so the axles, front end and front driveshaft don't spin. Part time kit or not, it will drive without the front shaft.

[hatzie]

I had a 79 Dodge W200 Power Wagon and a 75 GMC K20 with that transfer case. I blew the front shaft in the Dodge and the GMC.

The stock "Full Time 4WD" NP203 had a lockable open diff inside so you could drive it "unlocked" on pavement without binding up the driveline. In stock dress it will drive in 4 HI LOC or 4 L LOC with no front shaft. It will not drive in 4 HI or 4 L. In unlocked mode the internal diff slips just like an open diff rear end with one wheel slipping.

The kits added locking hubs and modified the open differential in the transfer case.

This is the 101 thread on the NP203...http://67-72chevytrucks.com/vboard/s...d.php?t=415273