There is a rubber mount on the tranny. Not on the diff.

I should have some time tonight to monkey around with it. Hopefully this time my pics will take

 

How close is the WP pulley to the fan at rest? Is it possible the fan is swinging/moving back on accelleration? Some fans are mounted to the radiator with simple wire ties or plastic pins. The tranny shifting could be a second related issue. The engine rocks quite a lot depending on the resiliency of the rubber mounts, it could be that the linkage is close enough to the firewall/floorboards that when the engine torques the linkage hits, knocking the tranny into 2nd and pinning the linkage until you let off the throttle. Even though both the fan and tranny issues are happening at the same time, they may not be caused by the same thing. On my Solstice a hard 1-2 shift can sometimes turn on the wipers.

 

I got home from work today & before anyone could rope me into a bunch of honeydo chores I ran to my garage & started looking around.

First - in the bed of my truck is a sheet of 3/4 treated ply - I removed it so I could see the rear end w/o climbing under.



Note there is no rubber between the carrier & the mount.

Wait - it gets better.

It's not the best picture - but that black bar in the middle (looks like its coming out of the muffler to the axle) is in fact 1 of 2 track bars!!! WHO KNEW??!! HA



Since I had such good access I started taking some pics.

Like this one


and this one


and this one


Not sure if you can tell from these last two pics - but the cross member is not welded to the frame.

It is mounted to the frame using bolts through large bushings.

The last pic there you can clearly see a large gap between the rubber bushing & the thick stack of washers used to locate the axle.

When I hit the gas the entire rear end, cross member & all is lurching forward - pushing the drive shaft into the transmission - shoving the transmission forward - maybe 1/2 an inch - any more & it would drop into 1st gear not just 2nd.

So - now that I know what's up - I need to decide how to fix.

I could add more washers!!

Naaa - that would probably work on a chevy - I've actually seen it on a dodge - not a Ford though.

Suggestions team? I may be able to do this wrenching my self if its not too extreme.

 

Other side

 

 

It may be me, or the angle and frame of the pix, but that's the strangest looking uncaged Jag IRS install I've seen. I have no idea what the purpose of the vertical links in front of the carrier are supposed to do, and I don't see any radius rods to the outer hubs?
Here's a couple pix I found:

 

AXRacer, wouldn't those be lower rear axle mount and shouldn't they be lower control too, by being more horizontal to keep lower part of the axle from moving forward during hard acceleration.

 

I believe the vertical own will brevent the pinion from climbing the ring gear, but I agree that there isn´t anything preventing the forward movement. The radius rods are missing (i think from the pictures) but IMHO the onlky correct radius rods are the silver coated chassie ones.

 

I agree Jimcar, the Silver Frame (1st pic) looks the best of the three, the 2nd pic has a great lower mount looks great, can't see the upper mount, don't care for the axle shaft kicker bars, looks like it will bind (my like it better in person). I personally don't like the 3 pic at all.

 

What if I take out the two vertical links & install longer links to the frame?

I really want to have the axle x member welded in vs. The current bushing approach.

Or I could replace all of those washers with hockey pucks (not really pucks but some kind of larger bushing)

Thoughts?

 

I cant see anything wrong with the bushing design. Just switch the bushing with same size buth with radial steel flange. That one is designed to take axial forces. The one you have today is not. Welding will give you vibration you dont want.

 

Here you have a picture of a bushing design for axial loads

The two ones to the right has the raidal steel flange. It is however important that this flange is mounted towards the front of the vehicle and that the washers you have today are the same size as the outer diameter of the flange and ID close to the bolt.

I wouldn´t start by moving the vertical links they work good enough, ok tey might do a slightley better job closer to axial direction, but what you really would need are the radius rods if you dont have them.

 

The good news is that it is (relatively) readily corrected. The Jag suspension is really sweet for cruising.
OT: I had a '93 XJ12 (X3000) "VdP" that was the nicest ride, and sweetest stereo, in any vehicle that I've ever been in.

 

I would not use a rubber based bushing and I would go to a urethane bushing with the flanged end, that way you eliminate the washers. There are several companies that make them. They may make one for that application or they do offer universal bushing based on size. Worst case is you buy a larger one and turn it down on a lathe.

 

I'm just curious If you have any play where the front of the cab mounts to the frame.

Edit: I seem to have missed the entire last page of this thread.