What style ujoint for an 88 K5?

[K5Steve]

I am tracking my vibration problem and it keeps taking me to my ujoints.It had Spicer p171's in the rear driveshaft that were sliding around in the yoke.I replaced them with some cheap Kragen GMB 210-3105's and they are still sliding around causing my driveline to move.Which style are these ujoints and are they the right ones I should be using in my 88 K5 with 700r4?

 

[adamforsythe]

Hello,
My 1985 K5 had the same problem. Try replacing your U-Joint Straps.
Thanks
Adam

 

[K5Steve]

I did,the ujoint caps were spinning so I replaced the starps and now the joint moves side to side in the caps(caps not moving).I also noticed the yoke moving up and down in the t case.If I am under the truck and push up and down on the driveshaft it moves at the t case,I can see the yoke move in and out of the case about 1/16th to an 1/8th of an inch.

 

[randy88k5]

I think that might be your problem right there. The yoke should move freely due to axle ride height, but you should not be able to move it by hand. Something has worn too much at this point. Try to pinpoint exactly where the movement is originating from and figure out why. My driveshaft is solid when sitting, no vertical or horozontal play. Check u-joints, yokes, and straps again. U joint shold not move in the yoke. You might have rounded out the ujoint seating surface, and the joint will not hold steady. Fix that before anything else.

Might be time to upgrade to some better parts too if you got the coin ...

 

[adamforsythe]

Hello,
Ok I am sorry but it sounds like the little pin looking things in the caps on your U-joint are gone or you may have a small U-joint in there. If it was me I would replace it.
After doing some research this is the U-joint that will fit your truck:
http://www.napaonline.com/cgi-bin/n...r=28558612&prmenbr=5806&usrcommgrpid=53707279.

when you are pushing on the driveshaft does the slip part of the shaft move in the T-case or at the U-joint?
Thanks
Adam

I did,the ujoint caps were spinning so I replaced the starps and now the joint moves side to side in the caps(caps not moving).I also noticed the yoke moving up and down in the t case.If I am under the truck and push up and down on the driveshaft it moves at the t case,I can see the yoke move in and out of the case about 1/16th to an 1/8th of an inch.

 

[K5Steve]

The yoke moves,not the ujoint.The joint at the diff side of the driveline moves.When I push up on the driveline the yoke moves in and out of the t case about an 1/8th of an inch.

 

[randy88k5]

Your pinion retaining nut might be loose. Take the shaft off and see if you can pull the pinion yoke in and out. That should be in there tight. If not, you need to tighten the nut. Pinion bearings are probably shot if its been driven like that. Any leaks from the seal there?

 

[K5Steve]

No the yoke at the diff is fine and doesn't move.Just the yoke at the tcase moves.It's almost like the driveline is too short.Does anybody know the stock driveline length?
It's a bad pic but you can see how far out of the t case the yoke is.

 

[randy88k5]

I may not understand what you are saying. In order to move the driveshaft at the slip yoke end on the transfer case, something else needs to move also. The slip yoke is designed to move in and out a good bit, about 3" Id say. It takes up the change in driveshaft length during axle movement. It should not move when you tug on it though. I can measure right now if you neeed, but not sure what that will tell you. Just tell me which two points...

EDIT: Damn, just remembered I dont have a driveshaft in right now, but I do have two driveshafts laying around... and the tcase installed

 

[K5Steve]

It is hard to explain.When I push on the shaft the slip yoke moves but not the yoke at the diff.The u joint at the slip yoke looks tight and moves like it should when I push on the shaft.It's almost like the slip yoke isn't in as far as it should be.

 

[randy88k5]

ok, for the 10 bolt NP208 TH700R4 combo:
34" from 10b yoke hole to end of output shaft.
Output shaft sticks out of the 208 1" from seal mating surface.
The total length of the slipyoke is 9" from longest point (outside of yoke to splined end)

Hope that helps...

 

[K5Steve]

Thank you,I'll measure tomorrow

 

[dirtwarrior17]

first thing i had to to on my rig was a tranny swap, then pay for a new 10 blt yoke in the rear and get my driveshaft lengthenged... the u-joint actually fell out of the yoke because it got so worn down from the short driveshaft, sounded like i blew the rear end. good thing i had 4by... just pulled the rear d shaft and drove home in front wheel drive.

Looks like your rig is lifted... my money is on short d shaft.

 

[K5Steve]

Ok,I measured the driveshaft and it is 34 inches with the yoke,I measured from the end of the driveshaft after the u joint and it was 34 inches at the output shaft,the driveshat itself,no yoke was 31 inches from the ends of each u joint.I pulled the u joint again and put it back in and it was fine for a couple of miles.I got back under and now the driveline is moving up and down in the t case,like the slip yoke is too big for the shaft on the t case.Does this yoke look like it's sticking out too far?