transfer case ?s

[k5floyd]

well my truck started making a loud grinding sorta noise when doing 60 + and letting off the gas fast. it sounded like it was coming from the rear end. it would do it at lower speeds sometimes but you could hardly hear it. i replaced the pinion bearings and side bearings and double checked the backlash when i set it up. but the noise is still there. now im pretty sure its in the transfer case. anyone have any idea what in the tc would cause this? or do i just need to do a whole rebuild or what? or would finding another np208 or 241 and puting it in be easier? thanks

 

[4X4HIGH]

Did you get the pinion preload set correctly? This is done with a crush sleeve and a NEW sleeve must be used anytime you remove the pinion nut.

 

[MattK]

Did you get the pinion preload set correctly? This is done with a crush sleeve and a NEW sleeve must be used anytime you remove the pinion nut.

good point. another thing to consider is ujoints.

 

[k5floyd]

Did you get the pinion preload set correctly? This is done with a crush sleeve and a NEW sleeve must be used anytime you remove the pinion nut.

yes. and u joints are were the first thing i checked. theyre good and only a couple months old

 

[4X4HIGH]

I would next remove the rear driveshaft and lock it in 4WD then drive it to see if the noise is still there.

If you don't have a SYE then you can put a 2 liter bottle over the tailshaft and zip tie it so you can go for a spin really quick.

 

[87BrnRsd]

I would suggest trying what 4x4high said. I had the same problem as you (grinding noise come from the rear when I let off the gas at higher speeds) and it ended up being that my slip yolk driveshaft was too short and the slip yolk was sort of vibrating around in the t-case when the torque was off of it. I ended up needing to lengthen my shaft and add a cv joint.
-Harrison

 

[k5floyd]

I would next remove the rear driveshaft and lock it in 4WD then drive it to see if the noise is still there.

If you don't have a SYE then you can put a 2 liter bottle over the tailshaft and zip tie it so you can go for a spin really quick.

i could try that but it really only does it at higher speeds and ive heard you should not drive very fast when driving on just the front axle. and how would i zip tie a 2 liter bottle over the tailshaft. and wheather or not it still makes the noise what would this tell me?

I would suggest trying what 4x4high said. I had the same problem as you (grinding noise come from the rear when I let off the gas at higher speeds) and it ended up being that my slip yolk driveshaft was too short and the slip yolk was sort of vibrating around in the t-case when the torque was off of it. I ended up needing to lengthen my shaft and add a cv joint.
-Harrison

ive had the lift for over a year now, only 4", and it just started making the noise. if my driveshaft were a bit too short wouldnt it have done that when i first put the lift on?

 

[Confedneck79K30]

could be the ujoints, check them again, regrease them.... could be a loose chain in the tcase

 

[MTMike]

I had the same problem too when my truck had the 12" lift. After I lowered 'er down with 52/56 it went away. Check your driveline angles.

 

[k5floyd]

the transmission guy at work helped me with my truck today. the noise is def coming from the transfer case. if the chain is loose is there a way to tell if it is and tighten it? what else should i look for in the case?

 

[4X4HIGH]

If it is a loose chain then you need to tear the T-case apart and replace the chain and anything else that is bad while you're into it.

 

[sandawgk5]

Mine does this and it is the slipyoke vibrating on the tailshaft. It is caused by the angles on the driveline not being correct. The shackle flip rotates the pinion to the perfect angle for a CV shaft (atleast on my K5 it did). Me not being able to afford a CV shaft I just deal with it and check the ujoints often as they will wear quicker due to the vibes. You could also shim the rear to get the ujoint operating angles within range.

Ira

 

[k5floyd]

if its the slip yoke vibrating on the tailshaft why did it not do this when i first put on the lift. also i have had some wierd driveline issues. when i first put the lift on(well over a year ago) got bad vibes, no big deal. i just lowered the tcase with the factory spacers and the vibes were hardly there anymore. drove it like that for a while til the u joints wore out and then i replaced them and bought shims. after i replaced the ujoints vibes were totally gone so i never installed the shims. so i raised the tcase back up and they came back but could hardly notice them. i plan on putting the shims in but just havnt gotten around to it. what gives?

 

[warhorse]

K5floyd, I have the same problem with my 84 K5. I was wondering where you got the factory spacers to drop down the transfer case? Thanks

 

[k5floyd]

they are on the bolts on the bottom side of the tcase crossmember just put just put them between the crossmember and the frame

 

[warhorse]

Thanks! The grinding sound on mine started right after I bought the truck (all stock) and I tried to correct the rear end sag with 2" blocks. The grinding sound was hardly noticeable. I've sence added a 4" front and 6" rear suspension lift and the sound and the vibes have gotten worse. I'm sure it's got to be an angle problem. I hope. Thanks again.