Transfer Case Noise

[carguy571]

Ok, so i guess first of all i should say that im new here. I recently bought a 1980 K5 which has been giving me a few headaches. When you are going down the freeway or someplace where you can keep a high constant speed, under no load the transfer case makes an icky bad grinding noise. Does tha make sense? Its bad enough that you can feel it through the truck. Oh, i should probably tell you that the truck has a brand new TH350 and NP205 transfer case. Any help would be appreciated.

 

[JeremyK5]

Has your blazer been lifted? Have you checked your u-joints lately? If your blazer has a lift, the pinion dropping down when you coast can cause a marginal ujoint to bind and make a bad noise.
The only way a new 205 would be making the noise you describe would be if someone messed up or missed something when reabuilding it.
Maybe someone who has had this problem more recently can give you a more definitive answer. Good Luck /forums/images/graemlins/thumb.gif

Jeremy

 

[Hossbaby50]

I have to agree with Jeremy here. When I had a bad angle on my driveshaft from a lift and axle swap I could get some vibs. I would get some vibs when I was cruising at a highway speed under just enough throttle to maintain speed. It got worse when I would let off the gas and coast at the highway speeds (55+ mph)

 

[carguy571]

The truck is lifted. However, the u joing angles arent bad enough to cause that type of noise. Its like a gear grinding cause there is no lube type noise. (checked that though) Also, since i am retarded and cant type, what i ment to say was the tranny is new but NOT the transfer case. What actually goes out in these things?

 

[wadinator]

[ QUOTE ]
What actually goes out in these things?


[/ QUOTE ]

I don't know. I thought the 205's were bullet-proof.

 

[Mudstud]

I bet anything that the your driveshaft/joints need attention. How big is the lift? Is the 205 slip yoke or fixed yoke? First thing I'd do is put the truck in neutral and grab the rear shaft right where the slip yoke is and wiggle it back and forth to check for wear. Then measure the amount of slip yoke you have exposed. Then when you have the shaft out of the truck separate the shaft and measure the amount of slip yoke that was hidden. If you only have like an inch or so then that may be your problem. Before you separate the shaft, mark the 2 halves and align those marks when you put it back together. One other thing you might verify before touching it is look at the yokes on each end of the shaft, they should be in line with eachother. If you don't understand what I'm talking about just ask.
Also inspect the driveshaft itself and inspect the u-joint cups. They can sqeal pretty good when they are cracked.

Let us know what you find out.

 

[Geno]

Your going to think I'm crazy but before you tear into your transfer case, check your shifter lever, there are shims on each side of it , if these wear out the internal noise in the transfer case will resonate up through the shifter, Try putting a jacket over your shifter ,see if it muffles the sound, or put some pressure on the shifter from one side and see if the noise is quieter, Mine was so load you couldn't carry a conversation while going down the hyway. Just something to try, this was my experience.

 

[BILLY RAY]

when i install my doubler i was not running a c/v drive shaft and when i was on the pedel (the shaft had a load on it) it sounded all ok but when i let off it sounded like the whole thing was coming apart and all it took the fix it was a c/v set up on the drive shaft.

 

[Blue85]

I would check the U-joints first and then look to see if the noise goes away by messing with the shifter. Make sure that your hubs are unlocked, especially if you have auto hubs, which tend to hang up and make terrible noises when they're going out (I think those were available in '80). After you've checked on everything else, then open up the T-case to have a look. I don't know, but you might be able to get it open to have a look without removing it from the truck.

 

[carguy571]

Ok, so i spent a while looking at things. The truck has 4" of lift. All the u joints are good, it does have a slip yoke but the driveshaft has been lengthened so there is quite a bit of it in the back of the t case. Everything looks good underneath. One of the guys i work with said that the adapter between the transfer case and tranny can wear out and make noise??? Ive never heard of anything like that. Now in just confused.

 

[Mudstud]

Did you actually take the d-shaft out of the truck? Gotta do that to inspect the u-joint cups. They tend to look normal until you take the pressure off and bits of metal fall on the ground. Good luck

 

[Tuff84blaze]

If I was you and had an np-205 (and some money) I would just get a slip yoke eliminator kit, and a new driveshaft from "High Angle", this should cure all of your problems.