Heavy Vibration-Help needed

[thysvdm]

good day

I have a 73 Datsun 1200 pickup with a heavy vibration. the vibration is only when I gear to 4th gear and when I'm at speed and i put the car to neutral its even worse. I've fitted a new prop shaft, done the t-housing bush,put a new clutch, replaced all the mountings, put new , new inner and outer tie rod ends, everything has been replaced but the vibration is still there. I've spend thousands on the car but the vibration is always there.
I've even tried to re angle the shaft but that also did not work.
is there any thing else that can cause this heavy vibration???
I don't know what else it could be.
I'm not to sure if my Datsun is a 520, 521,320 or so!!
Does some one know what else can be wrong??

[datzenmike]

Tire / rim balance. Mud on rim.

Brake drum (broken ?)

 

The '73 should be a 620 truck. Engine tag on left side inner fender should say  PL620 somewhere on it?

 

You should have a two piece drive shaft. At the rear of the front shaft is a carrier or center bearing support with a rubber isolator around it. These tend to rot away and the driveshaft is unsupported and will vibrate.

 

 

 

Should look like this...

 

 

 

This one is gone away. The driveshaft will just flop around.

 

[Dolomite]

Jordie town, UK...Is there a chance its a Sunny truck he's talking about?

[thysvdm]

I think it's a 73. The guy I bought it from said its a 78, but I don't think that's right. It has a single shaft.

[flatcat19]

Does it happen at a specific speed?

 

Wheels out of balance will start to be felt around 35-40mph.

[banzai510(hainz)]

is this truck  lowered a lot. then the carrier bearing has to be raised up.  This happens a lot on 5 speeds installed and over 3 inch drop

[flatcat19]

is this truck  lowered a lot. then the carrier bearing has to be raised up.  This happens a lot on 5 speeds installed and over 3 inch drop

One piece drive line.

[banzai510(hainz)]

put on jack stands and in gear!!!!!!!!!!!!

[datzenmike]

Lift and spin the tires. Are they round??? Don't laugh, had this once.

[Eomund]

As you said you changed the shaft, they can be out of balance, and usually are weighted by the factory. Is it possible the driveshaft is out of balance?

 

Alternatively, what's the condition of your U-joints?

[bilzbobaggins]

Rear end loose? Loose u bolts? Where does the vibration originate from?

[thysvdm]

Hi all.

 

Thanx for all the replies. I have tried everything possible. Today I balanced my wheels my self and found that the left rear mag rim is buckled. I've been in the Tyre game a while and never have i seen a rim that is buckled to cause a prop shaft to vibrate that much. the vibration only happens in 4th gear from 70km p/h and faster and when im at that speed and I put the car in neutral it still shakes and makes that vibration noise. I will replace the rim tomorrow and see what happens. I just hope that is the cause of it all cause there is nothing else that I can replace or fix that can still cause this vibration???

[Eomund]

That sounds a lot like U-Joints to me. That center bearing bushing that Mike pointed out can cause this as well.

[datzenmike]

Swap it to the front. Vibration will move.