Let's play *Name that noise!*

[seanlsb]

Well I've spent my evening reading "noise" threads, and it seems like all of these noises have their own special nuances and quirks. So my 1974 FJ40 is making what I'll call a clunking noise when decelerating in gear. Here are the facts about the noise:

• it sounds like it's coming from the rear end
• the brakes do not affect the noise,
• depressing the clutch quiets the noise completely
• it happens in all 3 gears
• I just bought the darn thing

So the question is what's that noise, and is it detrimental?

 

[steverb]

u joints,
pinion bearing,
to much slop in the rear end, meaning gears not adjusted right.

 

[rockcod]

Chock the tires, take it out of gear, release the parking brake, crawl under the thing, grab the drive shaft and rotate it back and forth, see where the slop is located i.e. (u-joints, t/c output shaft, pinion flange) try lifting up and down on the drive shaft to check for play in splines of the drive line. Might as well check the u-bolts and leaf spring bushings since you are under there.

Good luck.

 

[Living in the Past]

The tailshaft of the 4 speed transmission are known to wear and well as the tranfer input gear that rides at that spot. Seen these worn to a point. You might check that if nothing else shows up

 

[Ziffdaddy]

Sorry to highjack, but I have the same thing with my 74'. Does yours have an annoying vibration/clunk when you let off the gas at speed? Kind of in that 'barely pushing the pedal but not actually accelerating' space? I was thinking rear end slop...is that something that can be adjusted? Does your tranny/T/C whine really loud, too? My U-joints seem fine, but when I twist the shaft back and forth, it does have play in the t/c and rear end....

Highjack over...please go back to your regularly scheduled programing...

Stephen

 

[seanlsb]

Hijack appreciated - seems like a very similar problem. Thanks for the tips, rockcod. I'll definitely do exactly that this evening. The only thing that left me confused (and concerned) about my noise is that the clutch completely silences it - made me think tranny, which concerned the bejeezus outta me.

 

[seanlsb]

The tailshaft of the 4 speed transmission are known to wear and well as the tranfer input gear that rides at that spot. Seen these worn to a point. You might check that if nothing else shows up

Tailshaft of 3-speeds same as tailshaft of 4-speeds? I have a 3MT.

 

[Living in the Past]

Tailshaft of 3-speeds same as tailshaft of 4-speeds? I have a 3MT.

No the tailshafts are different. The three speed is ten spline while the four speed is sixteen spline. The fine sixteen spline is stronger but it does wear easier.

 

[Pin_Head]

Bad pinion bearing.

X2
Either that or the nut backed off. Not an unusual problem.

 

[71AZFJ]

If the clutch quiets it , it may just be your throw-out bearing. Worth a shot. Good luck. >>>>>> I used to love her , But I Had To KILL HER . And Now Im Happier This Way.

 

[thetaxmonkey]

would bet the farm on U-joints, have had the exact same problem