Lurch problem 4.6iS (video)

[yes_its_neil]

Your symptoms are the same as I had with my 3.0D. I did have gearbox adaptions reset, but that changed nothing. I had my valve body replaced which fixed problem 100%. I found that putting the gearbox into M mode just before stopping would reduce the effect, I think because it would change down to 1st. gear earlier and avoided the THUMP change to first when stopped. The valve body I obtained was second hand through eBay, and fitted by the seller. Cost me around $4k (Aussie dollars), but some money refunded from the car dealer as the vehicle was recently purchased and although out of warranty, he did come partially to the party to the tune of $1500.

[Trasportador]

I'm having the same lurch issue with my 2002 4.6. With the AC on, the lurch effect is summarily gone, but AC off, it's definitely there. If I neutralize the car whilst decelerating, no issues. I'd hate to think I need to change the valve body. I'm going to service the trans myself next month and see if it gets better. Will be running the AC for the time being. The good thing is that the trans in the 4.6 is the same as the 4.4 in these years, just the transfer case is different, so a spare tranny should be relatively easy to find.

[Supr4]

Same issue. Did someone know if they were referring to throttle valve body or transmission valve body?

[Purplecty]

Originally Posted by Trasportador

I'm having the same lurch issue with my 2002 4.6. With the AC on, the lurch effect is summarily gone, but AC off, it's definitely there. If I neutralize the car whilst decelerating, no issues. I'd hate to think I need to change the valve body. I'm going to service the trans myself next month and see if it gets better. Will be running the AC for the time being. The good thing is that the trans in the 4.6 is the same as the 4.4 in these years, just the transfer case is different, so a spare tranny should be relatively easy to find.

Maybe a TC issue? I believe the 4.6iS trans is pretty different internally than the 4.4 and has a larger TC. The bellhousing is slightly different to compensate for the larger TC. They are pretty rare so rebuilding yours would be best...

[wpoll]

Originally Posted by Supr4

Same issue. Did someone know if they were referring to throttle valve body or transmission valve body?

Transmission valve body. Or just the solenoids usually.. common issue with the ZF 6HP26.

[Supr4]

Mine is 5gear. It doesn't do it all the time it's strange. I replaced maf and it did it less

[CapeX5]

[QUOTE=Trasportador;1052457]I'm having the same lurch issue with my 2002 4.6. With the AC on, the lurch effect is summarily gone, but AC off, it's definitely there. If I neutralize the car whilst decelerating, no issues. I'd hate to think I need to change the valve body. I'm going to service the trans myself next month and see if it gets better. Will be running the AC for the time being. The good thing is that the trans in the 4.6 is the same as the 4.4 in these years, just the transfer case is different, so a spare tranny should be relatively easy to find.[/QUOTE
Just to clarify for future users-this is blatantly incorrect. Besides the TC, there are extra clutch parts, valve body, solenoids, etc.

[Supr4]

I don't understand what's the cause according to you ?

[CapeX5]

Originally Posted by Supr4

I don't understand what's the cause according to you ?

Not a transmission guru, but could be a few things. Could be one of the clutch drums, a solenoid, cracked valve body, etc. There is a guy on youtube, Gary Ferraro that has some really good videos on this specific transmission in the 4.6. I would check those out

[Supr4]

Fixed by increasing drive position idle speed with dis.