2004 F150 FX4 rear-end
Thread Starter
|
New User
Joined: Jun 2005
Posts: 10
Likes: 0
From: corpus christi
2004 F150 FX4 rear-end
I need help diagnosing a problem. I have a 2004 150 FX4, and I think im having problems with the rear-end. When you start off from a dead stop, you can feel a pretty good clunk, and when you take the load off/decelerate, you can hear a distinct knocking noise, but as soon as you step on the gas agian it stops.... I've had people tell me it's a brake issue, and some tell me my diff is about to explode. It was recently serviced and the berrings replaced. I know when we bought the berrings, they didn't fit. Appearently it has a mustang rear end on it. or atleast thats what the ford house told us. Has anyone else had this problem or heard of this? any help is appreciated.
Junior User
Joined: Oct 2006
Posts: 94
Likes: 0
i just had my rear end seals replaced for the second time i have the 4.6 motor and mine is the 04 stx. i have noticed mine will clunk as it sometimes seems to search for the appropriate gear after decelerating and then when i reaccelerate. but if your still under warranty its best just to get it checked out and if your not happy with the results find another dealer for a second opinion. sorry i couldn't give any more info.
Thread Starter
|
New User
Joined: Jun 2005
Posts: 10
Likes: 0
From: corpus christi
tranny, fx4 info
to give a little more information on the truck... it just rolled over to 104k yesterday, so we have quite a bit of miles on it. we also stuck a borla exhaust on it along with a cold air intake. and just recently we added a leveling kit and new wheels and tires (295s... no big change) But our truck started giving us the same problem you described, and we actually had to have the transmission rebuilt at 84k. it was a problem with the new transmissions they decided to stick in em. there was some sort of tube that wasnt drilled properly at the factory. I cant remember exactaly what the mech. said, but it was definitely a factory problem. (I love the truck, but it seems to be full of factory problems...) im not sure if its the same problem your having, but it would be a good idea to take it to someone you trust and have them look at it. but we still cant figure out the knocking. it cant be an exhaust rattle because its to rythmic. it directley coincides with the speed... and I know none of those add ons would have anything to do with that knocking....
Last edited by hellbenttexan57; May 11, 2007 at 02:27 PM.
Logistics Pro
Joined: Mar 2005
Posts: 2,536
Likes: 200
From: southeast PA
I'd crawl under it and grab hold of the drivshaft at the pinion yoke. Try to move it side to side. If theres play, it's very likely that the pinion nut was overtorqued causing too much preload on the bearings, and it won't take long to wipe them out. The turning torque needs to be set properly, and some people think an impact gun cuts it, which it doesn't. As to a mustang rear, the FX4 comes only with the 5.4, which comes only with the 9.75 rear end. I haven't looked into it, but I doubt they could even fit it into the mustang, it has quite a large centersection.
MMNC (SS)(Ret)
Joined: Mar 2004
Posts: 11,594
Likes: 144
From: SE Georgia
the 1994-2004 Mustang runs a 8.8 rear-end, and I'm 90% positive the 2005 Mustang is the 8.8 also...the 8.8 has been in the F-150 and explorere from 1992-1996, and I think 1997+ explorers until they went IFS and IRS. maybe that is what they were talking about. Those axles are identical except for width.
the 97+ F-150 has a different axle, the sterling 9.75...which is NOT the Mustang rear-end
the 97+ F-150 has a different axle, the sterling 9.75...which is NOT the Mustang rear-end
Fleet Mechanic
Joined: Nov 2000
Posts: 1,713
Likes: 2
From: In my House
For the record, the Explorer used a 7.5" rear end. The same ones they usedin the Rangers. I really did wish that they used the Ford 9" rear end still. It was so nice to have the removable carrier!
MMNC (SS)(Ret)
Joined: Mar 2004
Posts: 11,594
Likes: 144
From: SE Georgia
I know the Exploder had the 8.8 in it...must have been the 97 and newer then. The Jeep guys use the Exploder as a source vehicle when upgrading their rear-axles. It's only 2-3" wider than a stock jeep axle.
I miss that carrier also...I'd have a 4.10 one for fun driving, and a 3.73 for when I want to wheel...oh well
I miss that carrier also...I'd have a 4.10 one for fun driving, and a 3.73 for when I want to wheel...oh well
Trending Topics
Post Fiend
Joined: Nov 2001
Posts: 7,698
Likes: 4
From: Neenah, Wisconsin
The 97+ F-150's with V-6's and 4.6 engines still have 8.8 axles....i believe that still holds true this year
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Jan 2007
Posts: 144
Likes: 0
According to the Factory Service Manual for the 2004 F150, you could get an 8.8", a 9.75" and a 10.25" rear end.
Mine is the 9.75", but the only way to know was to slid under the truck and write down the number on the rear end tag to cross reference it.
According to the manual, you have to remove the seals and bearings as a unit. I'm not sure why, but I suspect the answer will become clear once I tear mine down to replace a dripping seal in a couple of weeks. If the person who did your seals did not remove the bearings at the same time, could this be the problem? I can't imagine how or why though...
Doug
Mine is the 9.75", but the only way to know was to slid under the truck and write down the number on the rear end tag to cross reference it.
According to the manual, you have to remove the seals and bearings as a unit. I'm not sure why, but I suspect the answer will become clear once I tear mine down to replace a dripping seal in a couple of weeks. If the person who did your seals did not remove the bearings at the same time, could this be the problem? I can't imagine how or why though...
Doug
Junior User
Joined: Oct 2006
Posts: 94
Likes: 0
i discovered a leak for the second time last thursday & took it in again, this time they had to replace the bearings and the seal so hopefully this time they got it right, i'm up to 32,400 miles so they need to get it right.
Thread Starter
|
New User
Joined: Jun 2005
Posts: 10
Likes: 0
From: corpus christi
ok little update on the truck. the problem, for the first time in a while, seems to be gettin a little worse. you can drive down an alley way and it sounds like someones tapping on the on the frame with a hammer. It's never been more noticible than now. Does anyone think it could possibly be an axel shaft about to go??
Thread
Thread Starter
Forum
Replies
Last Post
