Clunking from rear end

[Allan T 97XLT 4x4 SOHC]

My wife's Exporer is a 97 XLT 4x4 4.0 SOHC. We recently had a problem when backing the vehicle and turning sharply at the same time. It felt like the driveline was binding up and then slipping to relieve the bind. It made loud clunks while doing all this and the 4x4 dash light would sometimes blink on and off. The dealer found a bad sensor that they said was letting the drivetrain shift into 4x4 low and that was causing the problem. Things have been great for about a month but now the drivetrain has started making a loud clunk sometimes when backing straight out of the garage and when making sharp left or right turns forward or backward. The noise seems to be coming from the rear of the vehicle this time.
I'd greatly appreciate hearing from anybody who has worked through similar problems or who might otherwise know what's going on under my wife's "baby".

 

[Rick]

I would take a good look at the U-joints in the rear driveshaft. That seems the most obvious source for the type of noise you describes, although it's rare for a U-joint to go out on such a new vehicle.

 

[Allan T 97XLT 4x4 SOHC]

Thanks, Rick. The vehicle only has about 55,000 miles on it but I'm worried that the binding the drivetrain went through when it was shifting itself in and out of low range 4 wheel drive may have damaged something like the parts you describe. I'll check them out.

 

[fresh]

Heck! I had a 97 Ranger 4x4 that the ujoint at the rear axle was froze up solid at just 23,000 miles! So that sounds like a good starting point to look at.

 

[ExploreMinnesota]

Are you sure the noise is coming from the rear of the Explorer? If turning the front wheels seems to cause it, then it is more likely a front end problem.

I had a similar problem about a year ago. The problem was the u-joints on the front axels. They would stick, so when i tunred the front wheels the u-joints would cause the axel to rotate just enough to start to lock the front end in.

 

[Allan T 97XLT 4x4 SOHC]

Problem almost solved?

Thanks for the input, guys, here's what's happening. I took it to a local mechanic that I trust and asked him to look it over. He noticed that when you put the automatic transmission in reverse and accellerate hard the vehicle slips out of gear like the transfer case is shifting into neutral, or at least not staying in completely in gear. This Explorer has the electric shift selector on the dash and there is no neutral position, only Auto, 4x4 high and low. The mechanic suspected that either the shift motor wasn't moving the shift fork far enough to stay completely engaged or the tranfer case has badly worn parts inside. The motor was the least expensive thing to try so we replaced it. It seemed to be fixed but after putting it on the rack one more time to double check everything it clunked and tried to slip out of gear backing off the rack. The transfer case is coming out tomorrow and being sent off to be checked and rebuilt as necessary. I suspect it was damaged when the bad sensor caused the unplanned shifts into low range 4x4 when backing up. The universal joints all seem to be okay. I'll let you know what they find inside the transfer case.

 

[TJ]

Allan,

I have been trying to resolve the rear-end/driveline clunk in my '93 Sport for about a year now. It only has 40K miles on it. I hope you have better luck than I am having. My Sport will generate a very audible clunk from the driveline/rear-end sometimes on a sharp turn and always when I shift from first to reverse or vice versa and let out the clutch. I've taken my vehicle to several Ford dealerships and independent tranny repair shops and 99% of them have told me "... they all do that" and that the clunk is due to "... slop in the drivetrain" or "... normal tolerance stack up". One Ford dealership did a partial rebuild on the rear axle for $700 with no positive result. I am about ready to give up. During the last year I've learned that the mysterious clunk is not that unusual in Explorers (especially 2-door Sports) and it really bothers some people but others, while aware, are unconcerned about it. With exception to those who have had bad u-joints, I have yet to hear of anyone who has been successful in really fixing the drivetrain clunk problem. I do hope you get satisfactory results in finding a fix without throwing too many dollars into it. Let us know how things turn out.

 

[chux]

help control trac

Help Allan Or Anyone
I to have a problem with my 96xlt shoc auto when i put it into reverse sometimes it locks into 50/50 split 4wd .
Its now out of warranty and i have taken it to two ford dealers in Australia and both cant fix it .
It locked into 4wd for both of them but with no codes they dont no what to replace , please let me no what and where is the sensor that your dealer replaced .
I have had flashing 4wd lights for over two years .
Helppppppppppppppppppppp.

[Edited by chux on 06-21-2000 at 07:34 AM]

 

[Allan T 97XLT 4x4 SOHC]

The shift motor and the transfer case were apparently not the problem. They pulled the transfer case and sent it to a transmission shop where they opened it up and found everything in good shape. The word they used was "pristine". They replaced the seals, reassembled it and put it back in. My mechanic friend suggested that I take it to the Ford dealer and have them run a diagnostic to see if it might be some sort of electronic problem.
The vehicle jumped out of gear on the way home just cruising at about 55 on the straight and level, then again after parking it in the garage. My wife put it in reverse to back up and move over toward her side of the garage a bit more and it jumped out of gear just sitting there.
I took it to the Ford dealership this morning.

 

[Alfredo]

I’m having a problem whit the electric shift in my ’94 XLT, and I find that there is an electronic circuit over the back fender, on the left side. I don’t know if in ’97 models this part exists, and it is in the same place.
I will replace this part in my truck because I suppose that it origins my problem. Please, tell me how finish your story.
I hope that you can understand what I say. Excuse me for my English.

 

[Allan T 97XLT 4x4 SOHC]

Thanks to Alfredo and everyone else for their input.
The Ford dealership diagnosed the clunking and the jumping-out-of-gear problems as closely related transmission troubles. We had them install a factory rebuilt transmission and those problems disappeared. I put the vehicle through all the maneuvers that used to cause the clunking and it hasn't made a sound. The new transmission is also much smoother in all respects than the old one.
I was extremely surprised to have transmission problems at 53,000 miles. The Explorer has been babied and driven like a car, never been offroad or towed anything.
Our troubles aren't over yet, now there is a whizzing noise that comes and goes at random. It is apparently coming from the transfer case that the first mechanic's transmission shop said was okay. Ford is going into it today to check it out.
I'm beginning to suspect that this Explorer was built on a Monday.
Allan

 

[Allan T 97XLT 4x4 SOHC]

The Explorer is fixed. The clunking and jumping out of gear was due to a transmission engagement problem which was cured with a reconditioned transmission from Ford. The reconditioned tranny uses a second-hand outer case but everything else is new and warranted by Ford for 24 months/24000 miles.
The whizzing sound came from a gear in the transfer case that had lost 1/16 to 1/8 inch of teeth from its engaging edge. The gear was in the set that drives the front wheels. There were also two guides or locating lips cast into the inside edge of the output hole for the front driveshaft connection that sheared off. This required a new housing piece.