4wd vibration?

[eclipse85k10]

I get a vibration in 4wd and its only when I apply throttle or on an incline. The vibration (almost banging) is there when the hubs are locked in, or the tcase is in 4wd or both.

The my 85 k10 has a 465/np208 and 10bolts. I just did the front driveshaft ujoints and everyone kept telling me it was the ujoints in the driveline. I just replaced all those and still the same noise.

I thought maybe it was the t-case mount was loose and the driveline might have been hitting the crossmember. But I checked and didn't see any signs of wear on the tcase and on the driveline.

 

[bot0611]

my truck vibrates when i have the hubs locked even in 2wd.. what speeds are you driving at in 4wd

 

[eclipse85k10]

any speed, when I apply the gas. Its a bad vibration. My suburban vibrated in 4wd when the slipyoke went bad, but this is bad and sounds like it is coming through the floor board

 

[JeffsJeep04]

Front driveshaft could be out of balance. I'm having a vibration problem with mine and that's my first check. Most driveline shops can check it out and balance it pretty cheaply. I'm just waiting for a break in the snow to yank the front shaft and take it in.

 

[Hogback Fabrication]

Check the condition of the front CV joint itself, not the two u-joints

 

[eclipse85k10]

the CV looked good when we put it back together and greased it, my only other thought is its the 208

 

[4xcrazy]

"vibration" such a wide, varying description of a word.

 

[eclipse85k10]

maybe more of a banging rattling. The more I try to explain the noise I think its my tcase. I've had bad ujoints and drivelines and that vibration is different. Ugh I dont really have cash to replace that right now. I'm really trying to get my suburban back on the road and not dump money in this truck.

 

[Stomis]

Front driveshaft could be out of balance. I'm having a vibration problem with mine and that's my first check. Most driveline shops can check it out and balance it pretty cheaply. I'm just waiting for a break in the snow to yank the front shaft and take it in.

I doubt it if its at slow speeds. Guys with square shafts have reported no issues up to almost 45mph if they build it well.

Id say either a tcase or pinion bearing going bad btw.

 

[eclipse85k10]

damn thats the second 208 this truck has eaten. The factory one split in half on me in the middle of traffic. I just talked to a mechanic friend about going to a 205 that'll mate to my 465 and he asked me why because he thinks the 208 is strong.

 

[Stomis]

damn thats the second 208 this truck has eaten. The factory one split in half on me in the middle of traffic. I just talked to a mechanic friend about going to a 205 that'll mate to my 465 and he asked me why because he thinks the 208 is strong.

Investigate a little first. Perhaps the flange bolt backed off? Take the driveshaft off and see if the flange on the tcase or the yoke has slop in it.

 

[4xcrazy]

I have a shaking vibration in mine when up at alittle higher speed, but i already know it's the excessive amount of slop in the slip on the front driveshaft.

And i was basically commenting on the work vibration as a means of informing what KIND of vibration and i think you got the hint

high speed vibration, almost a harmonic type, or a shaking vibration like that of a sloppy driveshaft slip section.

those high speed ones tend to be u-joint types, check the fluid level in your t-case, maybe you had a leak and didn't realize just how bad it was?

 

[eclipse85k10]

tcase fluid you got me thinking. It came pouring out which usually means to me the rear output on the trans is leaking since it was low. Could 90w be bad for a 208? since I think my 465 is leaking oil into it

 

[4xcrazy]

I dunno, never had a 465, i like my autos, i'm lazy that way

BUT i don't think it's gonna play nice in the t-case...

 

[Stomis]

Gear oil is no good for the aluminum tcases. The sm465 is open to the back of the adapter. Gear oil in the adapter is normal, plus the front of the 208 is sealed that I doubt thats the issue.

Be aware 208s and 241s only call for 5 pints NOT QUARTS. Ask me how I know

People think that the slip yoke throwing fluid cant be fixed. Mean while the real issue is the unit having twice the oil level in it its suppose to causing too much pressure on the seals.

 

[eclipse85k10]

if the input seal on the 208 is bad, then the gear oil from the trans can get in right? The oil that came pouring out of my 208 when I opened the plug was way too thick for ATF

 

[Blue85]

Did you check the slip on the front driveshaft? They always get loose eventually and when it does, you have a very out of balance shaft.

If you have a bad bearing in the T-case (front output?), then it should shake with the front shaft removed and the Case in 4x4. You can also eliminate the front axle as the source by locking and unlocking the hubs while the drieshaft is out.

 

[eclipse85k10]

Once I fix my header gasket (hate driving when blown gasket) I'm gonna try to get it across town to a friends shop. But a bad bearing on the output shaking the driveline is pretty close to what it sounds like. I did drive when the hubs in and the driveline out and it was good.

 

[K5dreamer]

this sounds exactly like my truck was behaving. the four bolts that hold the flange for the front driveshaft to the t-case had come loose, two were completely missing. i replaced all four with grade 8 bolts and tightened them down, and the violent vibration dissapeared.

forgive my lack of knowledge, but the t-case is always spining yeah? even in 2wd. because it transmits power to the rear driveshaft. if the vibration is only in 4wd, or when the hubs are locked, its related to the driveshaft spinning. so id say its the shaft somehow.

 

[Stomis]

this sounds exactly like my truck was behaving. the four bolts that hold the flange for the front driveshaft to the t-case had come loose, two were completely missing. i replaced all four with grade 8 bolts and tightened them down, and the violent vibration dissapeared.

forgive my lack of knowledge, but the t-case is always spining yeah? even in 2wd. because it transmits power to the rear driveshaft. if the vibration is only in 4wd, or when the hubs are locked, its related to the driveshaft spinning. so id say its the shaft somehow.

Yes but the front output section of the tcase doesnt spin in 2wd. So if it was a bad front output bearing it could be the tcase.