[98blackstallion]

I know this is a mustang tech forum but I see some actual ford techs on here so thats why I am asking here.


Hey guys My chick friend has a 98 ford f150 with the 4.6L and the 4speed automatic tranny. My concern is the noticeable clunk that the truck has when the trans shifts from 3-4 gear (at normal cruising speed) or when pushing the gas down in 4th thus making it kick down to 3rd. It only does it between those two gears too. The 1-2, 2-3, shifts are great and smooth but as soon as it shifts into overdrive it clunks alittle bit and when it kicks down from overdrive to 3rd? When you sitting still and switching from P to R to D it clunks alittle. Can someone help me figure this out. I am a Chrysler tech in a training and I need all the help I can get. So if you guys could help me with where/what I should check first and the diagnostic procedures I should use to determine this problem. I will be in debt to you if anyone can help.!

[SVT32VDOHC]

The 4R70W and the AODE are very similar. The 98 F150 has the 4R70W, but I know there is and overdrive spring in the AODE's that went bad causing a hard shift, but only from 3rd to 4th. A friend of mine had that problem in his 95 Mustang. A trans shop replaced his broken on for under 50 dollars. They just had to drop the pan and replace it.

I'm not saying that's your problem, but it is something to look into.

[98blackstallion]

Thanks man I see what I can find out!

[98blackstallion]

I was playing around with it tonight and heres what I've come up with.

When I was sitting at idle and went from Park to Reverse or Drive it would clunk alittle as it shifted to either R or D. So after that I got up under the truck and examined the u joints and didnt notice anything out of the ordinary. So I started to try pushing and pulling on the driveshaft to check for play. The rear Joint didnt have any at all but when I moved to the front it seems to have a slight little bit of play in the u joint. No much but alittle. U joints arent suppose to have any movement at all right? Could even the littlest movement cause a clunking sound?

[BK_CAULEY]

my 98 f150 4.6 had a e4od in it.

[Darkwriter77]

FWIW, is she driving it around with OD enabled under 55mph? It could be damage from gear-hunting a lot, because most people don't lock out OD when they're cruising around town or whatever under 55mph. I think the driver's manual of most OD automatic cars recommend 45mph as the minimum for it, but realistically, when you consider hills and so on, 55mph usually keeps it from hunting between 3rd and 4th.

Another possibility might be that it's a variation of the 3-4 torque converter shudder. I don't know if the F-150's have had this problem, but I know that it was common on many Crown Vics from '92 up until '98 or '99 when they dropped the 12" converter and went with a 11.25" converter. If it hasn't been done already, a complete drain and refill with Mercon V usually helps in that case, but if it's been doing the shudder for awhile, the damage is already done and the torque converter will need to be replaced to solve that issue.