She goes thump...

[burrfree]

It's me again. I wanted to post another question about my truck. When I come to a stop and then take off, I get a pretty good thud. I had a 95 F150 that did the same thing and I used to just remove the rear driveshaft and lube the splines. It would go away for a month or so but always come back. Is this just a Ford thing?
Also, if I give it full throttle at low speed, she'll have a slight drive line shudder. What say you all?

[paulgl26]

tag
same thing with mine just a small bump

[Austinj427]

U-joints? Do they need replacing?

[burrfree]

I remember replacing u joints on my F150 and it didn't help. I don't think these are bad either, it doesn't clunk going in and out of gear. IIRC, back in the day, Ford had some special lithium grease or something for the spline end.

[chrispaine]

Bump..
Same thing here, I got somewhat used to it but it still bugs me. I did take the Dshaft down and put some normal wheel bearing grease on the splines but maybe I need better grease?

I would really like to stop this!

[2001pwrstroke]

The actual splines on the original slip yokes are pretty darn coarse cut on ford transmissions depending on the models......Some of the TSB's touched on replacement hard chromed yokes installed on the driveshafts that really worked well when used with a little bit of moly lube. Remember a lot of grease on a original slip yoke can be just as bad as a no grease, it almost becomes like a sealed plunger effect that makes a seal that "bumps" every time you start and stop.


Hard Chrome Yoke and small moly lube was a 200k fix on my truck.


The other thing for people to think about is this.....by simply the drive shaft turning, the drivshaft gets longer and shorter (ie back and forth) every revolution and sets up vibrations at odd speeds that people chase, well most of the time it's related to slip yoke problems because the slip yoke is bound up and is not moving freely.

[chrispaine]

Originally Posted by 2001pwrstroke

The actual splines on the original slip yokes are pretty darn coarse cut on ford transmissions depending on the models......Some of the TSB's touched on replacement hard chromed yokes installed on the driveshafts that really worked well when used with a little bit of moly lube. Remember a lot of grease on a original slip yoke can be just as bad as a no grease, it almost becomes like a sealed plunger effect that makes a seal that "bumps" every time you start and stop.


Hard Chrome Yoke and small moly lube was a 200k fix on my truck.


The other thing for people to think about is this.....by simply the drive shaft turning, the drivshaft gets longer and shorter (ie back and forth) every revolution and sets up vibrations at odd speeds that people chase, well most of the time it's related to slip yoke problems because the slip yoke is bound up and is not moving freely.

crap I put a ton of normal old grease on mine, guess I'm taking it down again.. why grease should I use? thanks.

[2001pwrstroke]

I would use a thinner almost moly lube, you will probably see when you take your drivehaft out that it will "pop" out--that you dont want. Clean off your old greae get some grey looking moly grease from the auto store, put some on it and you should be all set. Make sure you get the grease out of the bottom of your yoke also.

Expecially if your yoke goes into the tranfer case, the tranfer case lube is "suppose" to lube those splines but in reality they don't to eliminate the problem in real life.

[smokenstroke]

My dads 01 has done this since new. he asked a tech about it and they told him its normal but i dont remember what they said it was? His just does it once after he's been sitting still for a while holding the brakes. Sound like the same thing yalls it doing?

[paulgl26]

i have to try the grease on yoke
i checked everything else