[1995f1504x4]

when i start moving from a stop, a very loud clunk is heard and felt. it sometimes shakes my whole truck. i know it is not a u joint, ive checked all of them. i thought tranny mount because the noise only happens once until i stop again. which would say to me its a mount or suspension part. the tranny mount appears in good shape. i looked at it closer and discovered the bolts on the bottom of the mount were loose. so i tightened the crap out of them since ive noticed this before. but never in the past have i had a clunk. which leaves motor mounts. and they are tricky to look at for whatever reason but they appear good as well.

help please.

 

[Ziggy]

Since clunk is heard/felt when you accelerate, I would suspect a bad engine mount or mounts. Mounts can look good because of the weight of the engine sitting on them when in reality they are cracked and the rubber is torn. Since you said your tranny mount bolts were loose, this would make sense as the extra torque on the tranny mount from the engine moving is loosening the bolts. Best way to check the engine mounts is to either pick the engine up with a cherry picker or lift up on it from below with a floor jack and watch what your engine mounts do.

 

[FirstPriority]

Another way to check them is to put vehicle in drive hold the brake and give it gas. With the hood open you'll see the engine jump pretty high. Doing this in reverse will check the other mount. Crazy Hialeah way of doing it but has worked for me over 20 years.

 

[351w500]

Bad spider gears, Pull the diff cover and inspect them.

 

[TheUnforgiven]

check the mounts first. it'll take you 30 seconds.

 

[351w500]

He could have the rear cover off in half that time if he used 10 air wrenches at the same time....shit.

 

[TheUnforgiven]

because that's practical.

 

[351w500]

i been drinkin'

 

[nevadagary]

Could also be worn ring and pinion giving you backlash.

 

[nevadagary]

He could have the rear cover off in half that time if he used 10 air wrenches at the same time....shit.

Aw hell just go to Ford Sterling and get a 10 way. That's what they use there. Tighten all 10 at the same time.:toothless

 

[TheUnforgiven]

i been drinkin'

when aren't you? :goodfinge

 

[351w500]

im not ......when,......f-k.r !

 

[TheUnforgiven]

you got nothin :goodfinge

 

[351w500]

i swear ta DOG if i could stand up at all right now....

 

[TheUnforgiven]

bring it sally

 

[351w500]

i just got pwn3d huh-

 

[hizootiemizark]

I had the same problem with mine for years. Greased the slip joint a couple months ago. It smoothed right out. Search grease slip joint or yoke. There is a great instructional post with pics. Easy job about 30 min. no problem.

 

[JohnMcD348]

I've got something similar but it doesn't happen all the time. Sometimes, if I start off hard, it sounds like metal tearing and a loud clunk. It sounds like it's coming from somewhere between the transmission and drive shaft. I've looked under the frame and all looks good. I guess I need to grease the joint or could it be something else?

 

[thin blue line]

good call on motor mounts and tranny mount. do that first, then check slip joint and lube it up. may be a pinion bearing going bad and letting the ring and pinion to move up and down on take off. i would also check the u-joints to ensure they are tight and that the rear is not moving around.

 

[JAYNESS the Great]

Could it just be that the driveshaft slip joint needs to be greased? I've heard that's a common problem.