Need help figuring this out.


Have another issue with our Van, this time I think it's a Tranny issue
though i'm not quite sure.

Now when driving it makes a weird sometimes loud clicking noise. Best way to describe it would be to picture a bicycle with a playing card attached to a spoke, only use several cards instead of one and on both wheels, then drive down a hill really fast. I have ruled out the suspension and rear axle, Had the rear jacked up and ran the engine to spin the rear wheels and see if I could hear a noise, I did not. I realize weight on the axle plays a role so I did another drive test this time I played with the gears a bit, shifting into Overdrive, then back to Regular Drive, 1st, Neutral, etc. Shifting between Reg and OD quiets the noise, putting the van in neutral while it's rolling stops the noise altogether so thats where I ruled out the rear axle. The noise is not present while backing up, sometimes putting it in neutral before putting it in OD or Reg Drive prior to takeoff quiets the noise as well, but that doesn't always work. Seems to be getting worse it used to be only an occasional clunk which I thought might be the suspension since it has seen better days, now this and since it's effected by what gear the tranny is in I don't think it's the suspension.

I thought at first it might be a tranny mount since it hasn't been changed in years but I would think if that were the case the noise would be present in all gears, even though I don't think it is the mount the fact it is old is not helping matters.

It kind of sounds like it could be the park lock mechanism, I do not know much about Automatic Transmissions this is basically uncharted territory for me in the world of Auto Repair. I can remove a transmission, and install one, as well as hook it up properly but I don't know the first thing about servicing one short of changing the fluid.

Vehicle and Transmission Specs:

Make/Model: Ford E150 Club Wagon XLT
Year: 1985 (Vehicle and Tranny)
Transmission Type: Automatic Overdrive (AOD)
Mileage: Over 100K don't have an exact #

It does have a locking differential, not sure what relevance that is but thought I would throw it in .

 

have you thought of the u joints; the nosie you describe sounds like the u-joints are gooing bad. when you put it in nutrual you take all presure off the shaft and there for no noise. the easest way to check this is to park the van on a straight road / drivewya block the wheels and then put it in N climb under it and grabe the drive shaft and wiggle it in and out and side to side look for movement and noises. this will tell you if it is them or not. i hope this helps

 

I have a E150 Conversion & a Yr & a 1/2 ago my rear U Joint went out & damaged my yolk (that holds the U Joint on driveshaft to trans & the rears) Had a time getting a replacement yolk (Found a 2 Yolk driveshaft fm a Ford 4x4 in a junk yd-Still have the remaining yolk & shaft for spare) Better replace it quick because yours as wellas my 1992 model don't hv greese fittings so U can greese the fm time 2 time like the old vans. Check, any looseness in play, Replace & pack the cup w/plenty of Symthectic greese fm a tub otherwise U'd have to search high & low 4 new yolks Not easy Believe it..Nuff Said!

 

I think the U-Joints are fine, that was the first thing I suspected when the noise began, I checked for play, solid as a rock, driveshaft does not wiggle on either end. It is a two piece driveshaft (should have mentioned that originally sorry) the center piece that connects both shafts looks fine as well. I opened the Differential Oil plug suspected Gear Oil to seap out, nothing. There is some in there but ya gotta feel for it and i'm not sure of the oil level or if it was just residue I was feeling on the Pinion Gear. It's black and has that Motor Oil in the driveway look so it could use a changing. I'm not really sure this would fix the problem though as the noise sounds like it's coming from where the Trans and Driveshaft meet. Still wouldn't hurt to change the Diff Oil so I will do that as soon as I can.

I drove it again the other day, the noise seems to appear when it's under load (Initial and Hard Acceleration, etc), it's loudest if the van is going uphill. It will fade when coasting and still isn't making a sound when in Reverse. Last time shifting between Reg and Overdrive did nothing to quiet the noise only coasting and putting it in Neutral would quiet it so i'm thinking it's getting worse.