Clunk somewhere in driveline

[Danish Farmer]

When I release the throttle, and press it down again, a clunk is sounding from somewhere in the driveline. Sounds like comming from the middle of the truck or somewhere behind that. It feels like there is some sort of slack too. This thing is getting more and more. Truck has 163 k on it, and I don´t know her history

Is there any particular points on a 1995 6,5 driveline that I want to check for wear ?
When i changed oil on the transfer case it looked nice and red. So did the tranny oil. Have not had the pan of the rear diff. yet.

Best regards Max

 

[DieselCash]

Sounds like a U-Joint.

 

[trouttrooper]

x2, ujoints. I'd do front and rear driveline if they are truly original's. Get it all done at once.

 

[NVW]

x3, much cheaper than transfer case problems too.

 

[Danish Farmer]

Well... no u-joints had wear to them. When i grab the shaft going to the differential, i can turn it some from side to side before it moves the wheels. Seems like there is a good amount of slack in both the diff. and in the transfer gear.
Since i cant move the axle up and down, would it mean that the ingoin bearings are ok. ? Would the slack then be in the cams ?

Best regards Max

 

[schiker]

It could be a transmission issue? Not sure of the solution but something with the electronics when the ECM commands lock up from unlock with fuel pedal input. Might want to look for threads on transmission problems maybe solenoid issues????

Other things to look at....

Try to move the driveshaft where it goes into the transfercase. I read there is a bushing in the tailhousing (with the slip shaft yoke / output shaft of the transfercase).

Also, I think GM would drain and refil the rear axle lube with high quality synthetic lube (with good extreme pressure package and shear viscosity strenght). I think this dampens the clunk but does not solve it.

 

[Danish Farmer]

Thanks schiker. I hope that your suggestions will help.
In the meantime I run over a Burb that is sold as parts.
Would that transfercase eventually fit on my pickup if both vehicles are 1500´s ? and same year

Thanks

 

[schiker]

I don't know. I believe there are at least 2 different transfer cases. I believe a Borg Warner and a New Venture Gear. Not sure if they are interchangeable or if there are any clear distinctions between which trucks had which transfercase.

My 97 has a New Venture Gear (NVG). Mine has a metal tag on rear of transfercase.

 

[NVW]

I believe the 3500's have the borg warner. Is it NVG or NP (New Process)?

 

[btfarm]

I believe the 3500's have the borg warner. Is it NVG or NP (New Process)?

I think NV was the progression of NP to a new corporate organization Leo. Meaning they are the same company.
I tried to find a pic of the NV circular nameplate but couldn't in this computer.

 

[WarWagon]

I have slack in the rear end, but, not the transfer case. Have you drained the transfer case and looked for part numbers in the oil, aka debris?
Is this a 2 part drive shaft? And the following apply to a 2 piece: Center bearing condition? Spline condition and grease level? Dry splines will clunk.

 

[Danish Farmer]

I remember the red metal name plate on the back but not the name. Yea when i changed fluid it did not look bad. My shaft if one piece, but thanks anyway for info about if it was in two pieces.

Reckon I better write down some numbers and take a look at the one on the burb.
Maybe i can cure it by getting a transfer case not as worn as mine, and put in the heavy grease in the rearend like mentioned above.
The case has a crack too going from the add plug to the level plug causing a oil leak. So many things could end up being fixed with a swap if possible