Thud after stopping.

[2001ExpSport]

OK, about 6 months ago I noticed a thud in the seat of my pants when I come to a stop. If I stop slowly there is no thud, but if I have to stop quickly there is a thud just after I stop. It will either thud after I stop or thud right when I let off the brakes to go. I recently had my brakes done so wasn't that because it still does it.

My concern is that this may be axel rap? I have no idea what is casuing this. When I stop in neutral it doesn't thud. The tranny shifts fine up and down, I tightened my shackles(stock), leaf springs, axel bolts...you name it, I tightened it. I am lost as to what this could be.

It feels like something untwists when I stop or let of the brakes. It doesn't make a sound, just a thud is felt.

Oh, I have an add-a-leaf back there too, but it was fine when it was first installed.

 

[Jason_25]

Oh another thing it could be could be your diveshaft slip-yoke needs to be greased.

 

[Positive Vibes]

Mine would make a similar thuding noise only when stopping quickly. It was my radius arms. They were cracked where you couldn't see, so it was hard to locate the problem.

 

[ok89]

I noticed a thud in the seat of my pants

Ummmm are you sure its a problem with the truck?

 

[2001ExpSport]

Originally posted by ok89

Ummmm are you sure its a problem with the truck?

Jackass

 

[2001ExpSport]

Originally posted by Jason_25
Oh another thing it could be could be your diveshaft slip-yoke needs to be greased.

Ya, I'll check that out.

 

[socky3850]

I agree with Jason_25 - Lube your slip yoke.

 

[Jason_25]

But don't expect positive results. I lubed mine real good and it made no difference.

 

[2001ExpSport]

Heh, it figures...

 

[bentley]

I just had the same problem i went to a suspension shop and tranny shop with no luck finally i went to the dealer and after some driving around they told me there was play between my slip yoke and the driveshaft. They said i needed to replace the driveshaft @ $600. i told them just to grease it up and it was fine for about 5,000 miles and now its back. I'll get around to re-greaseing it sometime soon. Hope this helps.

 

[espnfreak]

Yup, same here, I was just gonna suggest that as I opened the thread. I think im gonna put synthetic AMSOIL grease on it. That stuff should work well.

 

[wallygetsit]

This problem only occurs, as far as I know, in the Sport model. My '95 did not do this, as it was a 4 door, however my '97 Sport 'thuds'. Friggin' annoying. Everyone I have talked to says lubricate the slip yoke.

Where exactly do I lubricate the slip yoke?

 

[Jason_25]

Take the driveshaft off when you do it. It's easier to pack grease in there.

 

[BigOne]

Are you serious Jason_25 Take the driveshaft out! Did they not supply us with a grease fitting in the slip yoke like all my Ford F series trucks have had all along?

I haven't been under there so I don't know. Haven't had the truck long but it too does a little thump on stopping only if you stop a little suddenly and let the truck jerk back a bit.

 

[TPLYNCH]

This thread reads like something out of a ****o mag......

 

[Jason_25]

Originally posted by BigOne
Are you serious Jason_25 Take the driveshaft out! Did they not supply us with a grease fitting in the slip yoke like all my Ford F series trucks have had all along?

I haven't been under there so I don't know. Haven't had the truck long but it too does a little thump on stopping only if you stop a little suddenly and let the truck jerk back a bit.

Yep that's right, no grease fitting

It's really not tough at all to remove, just don't let it hit you in your head when it comes out, I know from experience! Also, be sure to put some spraypaint on each end of the driveshaft so when you put it back on it will still be balanced.

 

[2001ExpSport]

BIGONE, it's real easy to do. You'll need a 12 or 13mm 12 point socket(can't remember the size). It has to be a 12 pnt though. Jack up one rear wheel. Leave it in park and break loose the bolts you can get to and then take them out. Then put it in N and rotate the axel to get to the bolts on the other side. Put it back into P to break loose those. Once they are all loose you can slide one side towards the other and it will come off. If it is stubborn, tap the yoke with a hammer lightly. Be careful, if you don't have leverage it will come down on your hand. That might hurt a little.

 

[Diff Whack Daddy]

This is a pretty common problem. I think that it is either the driveshaft slip yoke or the tranny mount itself. The stock mounts actually have alot of play in them, about 3/4 to 1 inch of movement. I replaced my tranny mount with a poly one from energy suspension, but you have to customize your tranny crossmember to do it. Since I have done that though, there isn't the slightest amount of thumping.

 

[2001ExpSport]

Originally posted by Diff Whack Daddy
This is a pretty common problem. I think that it is either the driveshaft slip yoke or the tranny mount itself. The stock mounts actually have alot of play in them, about 3/4 to 1 inch of movement. I replaced my tranny mount with a poly one from energy suspension, but you have to customize your tranny crossmember to do it. Since I have done that though, there isn't the slightest amount of thumping.

About a yr after I bought my truck I found that the tranny crossmember bolts didn't have any nut's on them. So, the tranny had been jumping around under there...that was nice.:frustrate