Weird breaking noise.

[TexasNomad]

Guy guys I was out driving around today and when I hit the breaks I hear this dull thunk sound, and its only when i'm moving at about 35+ and it shoulds like its coming from the middle of the truck..
I crawled around underneath the truck and could find any thing..
Any ideas?

 

[LEB Ben]

U joint going bad? Did you notice any play in your driveshaft at either end? That's what I'd put my money on if it's in the middle of the truck. Does it just happen around 35mph...or up to 35mph? I don't think it's a brake related issue...although, one time I had a pad disintegrate on me and made a similar sound, but that sound came from the wheel and then I heard the dreaded brake grind.

 

[TexasNomad]

Yeah I checked my joints and they are nice and tight no play, could it be in the tranny?

 

[1985 Ford F-150]

Is the mount still on there? I had my rear tranny mount break the bolt that supports the rear of it on the cross member.

 

[blacksnapon]

Look at your radius rod bushings. If they're ok, then go to the caliper mount bolts.

 

[TexasNomad]

Cool thanks guys!
I"ll check it out..

 

[Blue Bomber]

i get that all the time. i found it to be my seat mounting bolts are loose (yeah, the're still loose....IM WORKING ON IT) see if there is anything loose in the cab.

 

[tomtoc]

i get that all the time. i found it to be my seat mounting bolts are loose (yeah, the're still loose....IM WORKING ON IT) see if there is anything loose in the cab.

on that note, i had a friend that had a loose spare tire under his explorer. not exactly the middle, but doesn't hurt to look.

 

[Mil1ion]

ah yes the infamous Ford Truck Thunk.

Solved on 4 x 2's by stuffing thick grease in the Driveshaft to Transmission union to absorb and remove the clunk.

 

[TexasNomad]

ah yes the infamous Ford Truck Thunk.

Solved on 4 x 2's by stuffing thick grease in the Driveshaft to Transmission union to absorb and remove the clunk.

How is that done Dennis I can't seem to find any grease fittings there?

 

[Mil1ion]

Remove the driveshaft and stuff it in by hand. about hand full does it .
I use disc brake bearing grease.

 

[Old Ford Blue]

Huh, I've never had a ford do it, but my moms Pukon XL does it ALL the time and its very noticeable.

 

[Alvin in AZ]

"when you don't know what's wrong, just make everything right" -Jack Duncan
(he was an extra good signal maintainer, he could fix anything! and quick too)

That worked for me when my pickup finally got the death shakes. LOL
Only I ain't so quick.
Because...
"it takes me longer when I get in a hurry :/" -Alvin

Danggit.
Stop caring what's wrong, just check everything.
It ain't that far from one corner of it to the other!

"you don't know what you are going to find until you look" -Alvin

Might find more than one thing wrong, one causing a thunk...
the other some little something that doesn't make a sound but
the accident investigator would've found after you were dead?

"you aren't going to find it if you don't look" -cowboy buddy of mine

Alvin in AZ