Don't laugh at the question...

[BigSur]

As some of you know i have had a rattling sound coming from under or infront..well somewhere on the truck when the truck is in drive and under load. I was first told it could be the heat shields so i removed all of them and still the same rattling sound. I was then told it might be a hairline crack in my exhaust down pipes so i replaced those. Same sound. I went as far as to replace all my exhaust pipes and muffler and same dang thing. So because this sound only happens under load and in drive i decided to jack the rear end up today put the truck in drive to see if i could pin point the sound and nothing. I heard zero rattle and i even got the truck up to 50mpg with the back end up on jack stands and nothing. So this leads me to believe that it has to do with the front drive train.

OK now for my retarded question. When my truck is in 2wd and i am driving down the road does my front drive shaft turn? Reason i ask is i took a rubber mallet and hit it and every time i hit it it rattled. Now i greased the piss out of it and i haven't gone on a road test to see if it worked but i might be thinking now that there wasn't enough grease inside the shaft and that is what was causing the rattle.

Thoughts?

 

[Rigger]

Truck in 2wd and hubs free: front driveshaft no turnie.

Truck in 2wd and hubs locked: front driveshaft turnie.

 

[Dynosoar]

The rattle you are hearing is likely to be engine knock. Does it only make the noise under load (accelerating or climbing a hill)?

Dynosoar

 

[NJTaco]

Rap lightly, then harder on your cats with a soft faced hammer. The INSIDE of the cat could be making noise. If the cat is really shot, "parts" of the honeycomb (assuming it is a honeycomb type) could be downstream in the exhaust.


X2 on the engine knock, too.

 

[NocalFJ60]

OK now for my retarded question. When my truck is in 2wd and i am driving down the road does my front drive shaft turn? Reason i ask is i took a rubber mallet and hit it and every time i hit it it rattled. Now i greased the piss out of it and i haven't gone on a road test to see if it worked but i might be thinking now that there wasn't enough grease inside the shaft and that is what was causing the rattle.

Thoughts?

You keep your hubs locked? Does it change if you lock them? Grab your driveshaft where it connects to the 3rd members and see if you have any play there. Try to moved it up /down and left/right.

 

[NJTaco]

As some of you know i have had a rattling sound coming from under or infront..well somewhere on the truck when the truck is in drive and under load. Thoughts?

How are your engine and trans/transfer case mounts?

 

[CruisinFJ60]

as long as u are in 2wd and hubs UNlocked then no it doesnt turn

 

[Marc311]

I rememer your earlier thread and thinking I had a similar sound. I also noticed I hadn't heard the sound lately.

Now the real shocker - I had my hubs locked all winter and unlocked them a few weeks ago. I can't say for sure that was related to my rattle, but I think you're on to something!

 

[BigSur]

I know its not engine knock or valve ticking. It does not have a rythmic (sp?) rattle to it and i recently did a compression test and she's running like a top minus the rattle. OK...with that being said about the front driveshaft that is going to lead me to there not being enough grease in it and that is what is causing my rattle. I'll check on that tomorrow.

 

[Dirtgypsy]

remove the front drive shaft and drive around. if it still makes the noise then I have no idea if it doesn't then viola. keep us posted.

clint

 

[3pits]

i thought I had a bad transmission, it turned out to be sticky valves, I had great compression ( oh yea and a broken spark plug)