Put the transmission in neutral, block the wheels for safety reasons if necessary. Crawl under and try to twist and move up and down and side to side each U joint while watching and feeling for any movement within the joint.

 

ive never dealt with neapco do they have any kind of warranty on them

 

I think your rear dif fluid needs to be changed. The shutter you feel is your clutch plates grinding. I had the exact problem you described. A fluid swap and a bottle of friction modifier and the problem went away. Ran me $125

 

The warranty is lifetime from what the package says.

I just changed my dif fluid two months ago and changed the cover on it..... I'm going to change my U-Joints tomorrow and if that doesn't work I'll look into changing the dif fluid again.

 

Well great...... First couldn't get the bolts off by hand... Used my jack to get them off... The clips came off relatively easy.... So then comes the part where you push the old one out right? No freaking way. I took a socket and put it between a C-Clamp first, then a shop clamp, and used as much leverage as I could muster but it wouldn't budge. I even put it under a solid object and used my jack in the same way as a clamp, the jack gave out.
I said screw it I'm just going to go to Sears..... On my way I call them and the supervisor tells me "We don't change U-Joints here at Sears". After dealing with them for a week they tell me no, even after I went in and talked to someone face to face.
I wish I had a press because all this hassle could have been avoided. Oh well I called the local 4x4 place and they told me to drop my truck off tomorrow.

 

They can be tough. I've changed quite a few, did my '77 last year and used sockets and my big bench vise as a press. I've also used the C-presses when available ...
... and I have used the hammer method.

In 1977 I was changing some and using a BFH and old sockets and somehow busted my left thumb. Smashed it good. Wrapped it well after cleaning it, damn it hurt. Should have had stitches but I was stubborn. To this day I have a permanent valley that runs the length of the thumb nail.

Yeah, got the joint done too. Damn, it hurt!

I haven't used that hammer method since ...
... but I still could if need be I guess, just keep my thumb out of the mix!

 

I forgot to mention I did the hammer method with a socket to no avail.... I used some pliers though, wasn't trying to smash any of my fingers as you mentioned.

Before you edited you mentioned something about going to Napa.... I can get my driveshaft there.

 

If you have a vise, I would say about 5 inch minimum. Use the vise as an adjustable 2 sided anvil. You will also need a large shot filled soft face hammer. Adjust the width of the vise jaws so the yokes sit on top of the jaws, DO NOT clamp it tight, now pound on top of the shaft with the soft face hammer. You will force one side loose, now turn the shaft a half turn and pound on top of the shaft again forcing the other side out. Kind of plan which order you are going to remove the pieces before you begin.

Once you get on to using this method, I'm sure you won't do it any other way. I learned this method while watching a mechanic remove a U joint for me after I broke a good vise trying to use the clamping force of the vise jaws.

 

Soaking it with PB Blaster helps.

Parts stores with machine shops can press the old joints out and the new ones in for you if you bring the driveshaft in.

 

dont use the hammer and socket method use the hammer and hammer method use a ball pein hammer that will fit through the hole in the shaft then you get your bfh and hammer away and you dont have to worry about smashin your thumb or use some penetrating fluid i like to use the stuff called kroil comes in an orange can kinda pricey but well worth it best stuff ive used

the only socket you need is one big enough to put on the bottom of the driveshaft to catch the cap on the bottom that falls out otherwise your hammerin for no reason if the cap cant fall out

 

Well a different shop told me today to bring it in and he'll do it for 80$ since I already have the parts and I've already taken the drive shaft off. Saved him half the work he said... Quoted me at 80$ pretty stoked about that.

 

Well it's not the U-Joints. They came out and there was no damage to either one. The Mech told me it's one of my COPs but can't be sure exactly which one it is until the check engine light comes on..... I might just replace all of them and the spark plugs because there's definitely a mis-fire. I'll ask in V8 engine section.....

 

The old shotgun method will eventually get it. $$$$