Clunking upon deccel

[jrdrag]

Hey Guys,

We just bought a 97 PSD 4x4 with a E4OD. When you are driving down the road and let off the pedal you here a clunking noise. We tought it was a tranny mount but it checked out okay. It also does the same thing when you put it in reverse. It almost seems worse. But it only does it when you first put it in gear. If you put it in gear, it will clunk, but if you hold the brake after it clunks and give it throttle, it won't do it anymore. Same is true for forward gears.

Look for some advice!

Caleb Peterson
3CMotorsports.com

 

[chewie95]

Working off memory here. Have you checked the u-joints? How about the transfer case...disengaged? Sorry for sounding simplistic, but you didn't mention if you checked those.
Hope this helps.
Matt

 

[DaveBen]

I remember u joints fitting these symptoms.

Dave

 

[lifted_up]

-popcorn does it 'clunk' if you tap the accelerator pedal up and down? Mine's been doing that also and I think it may be the ring and pinion. Jack the rear end up and put in nuetral and spin the drive shaft by hand and see how much spin it has before it catches in each direction. This is only an opinion but mine had a lot of play and that is why I think the cluynk is coming from there. How about getting an Austin group of SDD.com (ers) together?

 

[BIG JOE]

Hey Guys,

We just bought a 97 PSD 4x4 with a E4OD. When you are driving down the road and let off the pedal you here a clunking noise. We tought it was a tranny mount but it checked out okay. It also does the same thing when you put it in reverse. It almost seems worse. But it only does it when you first put it in gear. If you put it in gear, it will clunk, but if you hold the brake after it clunks and give it throttle, it won't do it anymore. Same is true for forward gears.

Look for some advice!

Caleb Peterson
3CMotorsports.com

Just a place to start.... re-grease yer tranny output (tail) shaft splines. Ford has a marine grade (Blue) grease.... slather it on the splines AND in the D'shaft ends. (look at the seals too)

You just bought it.... so you prolly don't know when the D/shafts were last serviced (?).

in & out of gear "Clunks", are often tranny tail shaft lube issues.

Just my .03

 

[jrdrag]

We had it up on the rack (My dad is a mechanic) and the ring and pinion seemed alright. We can check the splines of the driveshaft. It seemed like we had quite a bit of play in the transfer case. I wasn't underneath but it was a shaft towards the front of the truck so I assume it was a front drivesahft? I am not sure I will find out though. It almost sounds like something banging up and down. Like something is loose. We haven't checked yet but we thought maybe a bushing in the suspension somewhere is gone maybe? It makes the noise when you let off then again when you get back in the throttle.

 

[jvencius]

Stupid answer here, but have you checked to see if you have anything rolling around in the bed or behind the seat? I had something like that happening to me and I was starting to get concerned until I remembered that I still had my small drain pan sliding around in the bed and the clunking noise I was hearing was the pain bouncing around. I am too damn lazy to go back there and put the pan back on its shelf in the garage so now I just ignore the noise since I know what it is...

 

[BJS]

If you're running a Crew cab then it could by the hangar bearing or it may be the midshaft u-joint.

 

[powerboatr]

one more real odd thing to check
and i only mention it because we had a similiar issue and my dealer never could figure it out with my 1992 250 4x4 sc.
i found it one day at the boat ramp.
normally i drive up onto the trailer, my wife puts truck in gear in 4x4 low and off we went up the ramp.
but this particular time I pulled up on the trailer and leaned over and locked th bow. but some big dumb redneck starting backing his boat down right in front of my truck, I think he was p.o. because my wife backs the boat trailer better than most men and she likes to smile.
anyway I am standing next the left rear wheel. she givves it a little throttle and the truck goes shhhhhh BAM, and then starts rolling forward. I holler STOP. So i am standing there looking at the rear wheel trying to figure out what teh heck just happended. driveshaft is stil attached, no fluids leaking etc.
so off comes the big FORD wheel cover, i have her drive on up. this time no noise.
so we get home and i wash the boat , start to back it into the gargge and BAM it happens again.
now i am perplexed.
so i pull out into the street. and crawl under and look at everything.
have wifey apply throttle and hold the brakes while i lay under the truck(not safe) and BAM it happend.
whole rear end shook. so i tell her to shift into reverse and do it again, this time i am standing next to the left axle hub and wheel and shhhhhh BAM. problem solved. the bolts that hold the axle shaft into the hub were loose enough to allow the axle shaft to turn slightly and with some authority taking up the slack in the bolt holes.
I think they were to be tqd at 25 ft pound but i spun several off by hand.
kinda long but it was a neat discovery

 

[jrdrag]

OKay guys,

We put it back up on the lift and had the truck running and tried shifting from forward to reverse. It made the noise and we found out that the driveshaft turns freely about 1/4 of a turn before slamming into something in the rear end. The pinion doesn't move in and out or up and down at all like a worn pinion should. It does not howl either. What do ya think?

Caleb
3CMotorsports.com