2007 4.0 FWD motor mounts

[just Matt]

Has anyone had experience w/ replacing motor mounts on 07-08 4.0L resulting in improved shift feel? Less herky-jerky-ness under acceleration? We recently purchased an 07 Limited 4.0 FWD w/ 50k. The shift quality is quite rough, which I now know is not uncommon. I know there is a TSB for improving shift quality, but we spoke with one dealership who said they could not work on it if there where no SES warnings/codes present. I think that's a ridiculous statement and I will talk with some other dealers to try to get the TSB performed. In the meantime, however, it feels like some of the rough shift feel is partially due to too much physical movement of the engine & transmission under acceleration. I know the motor mounts have been a constant issue with these vehicles. We never had a problem w/ out '06 3.5L, but the 4.0L is much torquier. While brake-torquing in Drive, the front of the engine twists/raises up a considerable amount. Probably at least a couple of inches of upward/rearward translation. I went ahead and ordered front & rear motor mounts, Anchor brand, from RockAuto. I will report back after I've installed them. Any similar experiences? Tips? Suggestions?? Thanks, Matt

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[just Matt]

Well, I replaced the front mount Monday night, and WOW what a difference. That was clearly the problem. The acceleration and shifting is much smoother and quieter. No more clunking & jerkiness, and a less harsh engine noise under acceleration. These mounts are fluid filled hydraulic. The new Anchor mount (part number 3147), I could hear the fluid sloshing around when I shook it. The old mount, not at all. The lower stem/stud was seperated from the outer rubber shell, and all the fluid had apparrantly leaked out. It was simply allowing the engine to move until it hit the hard stop within the mount. I was not able to change the rear mount, as I was unable to jack the engine high enough to get the old one out. I was running into clearance issues to the firewall & radiator to get it any higher, and I was not willing to do any further disassembly. The front mount seemed to be the main culprit anyway. Hope this info can help someone else out in the future. If anyone's interested, I can go into more detail of the replacement procedure.

[spinedoc2304]

Hey Matt!

Brand new to this forum with this being my first post. We've also got a 2007 Pacifica 4.0 Touring with a collapsed front motor mount (just diagnosed last week). I would be VERY interested in knowing the exact procedure you used to replace the front mount. I just recently changed the mounts in my 1991 Mercedes 300E which were a piece of cake. Hopefully the Pacifica will be just as easy.

I also have the ESP-BAS and traction control lights on on the dash. The code says the steering angle sensor is the culprit. Any clues as to what I can do? Where is the sensor?

Thanks in Advance
Nick

[just Matt]

Nick,
It was all fairly straightforward. First, I disconnected the battery. I then jacked up the front of the vehicle high enough to be able to crawl around underneath, and supported it with jackstands. Getting access to the top nut on the front mount required a ½” drive universal joint (which I had to go buy) to get a socket on it. You’ll need a 21mm socket for the top nut, and I think it was an 18mm for the bottom nut. I used an impact to break them loose. Remove both the top and bottom nuts. You’ll also need to unbolt the rear lower mount and the passenger side “horseshoe” mount to allow you to raise the engine high enough to get the front mount out. The unbolt the rear mount, just remove the bottom nut where it bolts to the rear crossmember. The passenger side mount is underneath the air box, so you need to remove that to get to it. Once the air box is out of the way, just remove the two bolts where the mount is bolted to the frame rail. I actually used two jacks to jack up the engine/trans (w/ blocks of wood on top of jacks to prevent damage to engine/trans). I had one under where the engine & trans is mated (driver’s side), and the other under the oil pan (passenger side). The oil pan is cast aluminum, so it’s pretty stout. Using two jacks allowed me to tip the engine/trans as needed while raising it. Be careful when raising the engine so you don’t pinch or damage any wires, hoses, pipes, etc. Go easy and don’t force anything. My first obstacle was the side cover on the driver’s side of the transmission which was hanging up on the lower edge of the frame rail. It took some persuasion to shift the engine/trans toward the passenger side to clear the frame rail (gentle prybar action). At that point it starts to get pretty tight between the accessory drive belt/pulleys and the passenger side frame rail. It took me awhile to get it high enough to get the front mount maneuvered out of there. When putting in the new mount, be sure you have it oriented the right way (there’s an alignment pin on the top of the mount) before tightening the top nut. Slowly lower the engine/trans and be sure nothing gets caught or pinched. Reattach all the mounts, air box etc., etc. That’s pretty much it. Hope this helps. Good luck and be safe. Let me know if you have any more specific questions.

[spinedoc2304]

Thanks Matt