4R70W hard 2-3 shift at light throttle when warm

[brianl703]

I'll look more into the transmission issue after I replace the motor mounts...they are rotted to the point that the engine appears to be resting on the crossmember underneath.

It's very possible that's the whole cause of this issue...what appears as a rough shift may simply be the engine flopping around.

 

[97tbird]

it could very well be. I added a a bit of a very reputed ATF additive and the hard/shuddering shift has pretty much vanished for the moment - but I am skeptical still - it's just weird that stuff worked like advertised at least for the moment -

I also have a suspicion that my engine and trans mounts are rather shot ...
I might try to get those replaced, the 1-2 and 2-3 pistons upgraded AND perhaps an ATF flush/change also...

 

[brianl703]

The engine mounts are not a fun job on the Crown Vic. Tried replacing them a couple of days ago and came to the conclusion that this is either the worst job to do on that car or there's something I'm missing.

 

[97tbird]

yeah - i am not a very good DIY person anyway, so I'll end up paying to get it done

--the symptoms are still staying away -

 

[brianl703]

Time for an update.

The motor and transmission mounts were replaced yesterday. That job is much easier on a lift.

The hard 2-3 shift is much less noticeable now. I'd say it's more like firm than hard. I haven't driven the car much since yesterday (at least not in city traffic) so I'll report back with any additional observations later.

 

[brianl703]

Time for an update.

The motor mounts weren't the cause of this. It still shifted hard at light throttle.

What I did to fix it is to clean the MAF. This made it shift much, much better. The MAF was clearly not reading correctly because the long term fuel trim at idle was -6%. After I got done cleaning it, the long term fuel trim is +3% at idle.

I had cleaned the MAF before but only by spraying it through the screen. This time I removed the MAF from it's housing and used a q-tip soaked with CRC MAF Cleaner to clean the sensing wires. There was some black stuff which ended up on the q-tip so it was definitely dirty.

This also got rid of the early shift to 4th where it would seem like it was lugging the engine.

So yes, the MAF can cause shifting problems if it does not read correctly.

 

[Jim Allen]

Interesting. Thanks for sharing that. Might come in handy with my ford some day.

Are you by chance running an oiled aftermarket air filter? Some problems with that have been noted. Otherwise, in theory, they should never get "dirty" with a good filtration system. If no oiled filter, maybe a look at your filter housing and the way the element fits in the air box is in order.

 

[brianl703]

No, I am using a paper filter, and when I got the car several months ago it had a paper filter in it. But who knows what was used before.

 

[Colt45ws]

Yeah. That makes sense. I took the air box out once then forgot to plug the MAF back in before I drove it. Trans shifted really funny.

Interesting you got away with using a q-tip on it. Most would recommend not doing that. The last person I know of that did that had to buy a new MAF because it was so borked.

 

[brianl703]

You do want to make sure that the q-tip doesn't leave any fibers behind and you don't want to press real hard..in fact nothing more than a light touch. Other than that, I've done two MAFs that way and they both worked better when I was done.