Rear diff fluid change - noise
#1
Senior Member
Thread Starter
Rear diff fluid change - noise
Ok, I am still trying to get to the bottom of a clunk in what I think is the rear end of my truck. Bottom line, I get a clunking sound when I turn at low speeds, and it appears to come from the rear of the truck.
Sound reminds me of the clunk I had for a while when my spare tire was loose, but that is tight right now and clunk is happening.
I had the truck up at a tire place, asked them to do a shake test, nothing.
So, now I am wondering if it is my differential. I was having some chattering taking off about 25k ago, so I changed the diff fluid adding the Motorcraft friction modifier in the proper amount, and hadn't had a problem till recently.
So, is it possible that the fluid and friction modifier is no longer working, requiring a new change?
This is a daily driver, 2wd, no hard driving, no off reading, no towing. Any other ideas? It has the original tie rod ends and front end as best I can tell.
Sound reminds me of the clunk I had for a while when my spare tire was loose, but that is tight right now and clunk is happening.
I had the truck up at a tire place, asked them to do a shake test, nothing.
So, now I am wondering if it is my differential. I was having some chattering taking off about 25k ago, so I changed the diff fluid adding the Motorcraft friction modifier in the proper amount, and hadn't had a problem till recently.
So, is it possible that the fluid and friction modifier is no longer working, requiring a new change?
This is a daily driver, 2wd, no hard driving, no off reading, no towing. Any other ideas? It has the original tie rod ends and front end as best I can tell.
#2
Ok, I am still trying to get to the bottom of a clunk in what I think is the rear end of my truck. Bottom line, I get a clunking sound when I turn at low speeds, and it appears to come from the rear of the truck.
Sound reminds me of the clunk I had for a while when my spare tire was loose, but that is tight right now and clunk is happening.
I had the truck up at a tire place, asked them to do a shake test, nothing.
So, now I am wondering if it is my differential. I was having some chattering taking off about 25k ago, so I changed the diff fluid adding the Motorcraft friction modifier in the proper amount, and hadn't had a problem till recently.
So, is it possible that the fluid and friction modifier is no longer working, requiring a new change?
This is a daily driver, 2wd, no hard driving, no off reading, no towing. Any other ideas? It has the original tie rod ends and front end as best I can tell.
Sound reminds me of the clunk I had for a while when my spare tire was loose, but that is tight right now and clunk is happening.
I had the truck up at a tire place, asked them to do a shake test, nothing.
So, now I am wondering if it is my differential. I was having some chattering taking off about 25k ago, so I changed the diff fluid adding the Motorcraft friction modifier in the proper amount, and hadn't had a problem till recently.
So, is it possible that the fluid and friction modifier is no longer working, requiring a new change?
This is a daily driver, 2wd, no hard driving, no off reading, no towing. Any other ideas? It has the original tie rod ends and front end as best I can tell.
#4
Senior Member
check some easy stuff like the tailgate as well. I had a clunky noise coming from the back and ended up being the tailgate. I thought it would be something worse. I packed the tailgate hinges with grease, and lubed the latches and it went away.
#5
Senior Member
Thread Starter
Hmmm...I will check on the fluid. When I changed the differential fluid, I removed the whole cover, so I could get to the bottom of the pumpkin, and it was clean - no particles what so ever.
Hadn't thought about the tailgate, I will check that...
Hadn't thought about the tailgate, I will check that...
#6
heavy Oil
Yep they(fomoco) discovered the original recommended oil was to light. The person I got the truck from had it(rear end) rebuilt. When I get a vehicle the first thing I do is change all fluids. When I pulled the rear cover I noticed that the cover was showing burn. I checked and thats when I found the 85 140 or 90 140 deal as a service bulletin. Full syn with that x4 modifier. I have put a good 50 thou on it and it sounds good. I used the valvoline full syn. The front Diff did not change wts. I change all fluids underneath every 60,000 so I will be due shortly.
#7
Senior Member
You shouldn't have to do another diff service at 25k, so I would rule that out.
Something obvious and dumb... is there anything in the bed that may be moving around?
What about tight u bolts and or leaf springs?
Something obvious and dumb... is there anything in the bed that may be moving around?
What about tight u bolts and or leaf springs?
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#8
Senior Member
Thread Starter
Thanks for the responses...
Ok, the fluid I used was Amsoil 75/140; is this too light? Where the hell do I find 90/140?
I have been up under the thing, and I can't see anything that is loose, leafs are tight, spare is tight, bed appears to be tight. This only happens when I turn too, not on acceleration or deceleration, which I think rules out u-joints, doesn't it? I can't see or hear anything in the tailgate that would lead me to believe it is that, but I am going to get in there and grease it up anyway. Now, I have a POS ARE brand cap, that I guess could be moving around when I turn, but all the bumpers appear tight and I see no unusual wear...so I am still stumped.
Ok, the fluid I used was Amsoil 75/140; is this too light? Where the hell do I find 90/140?
I have been up under the thing, and I can't see anything that is loose, leafs are tight, spare is tight, bed appears to be tight. This only happens when I turn too, not on acceleration or deceleration, which I think rules out u-joints, doesn't it? I can't see or hear anything in the tailgate that would lead me to believe it is that, but I am going to get in there and grease it up anyway. Now, I have a POS ARE brand cap, that I guess could be moving around when I turn, but all the bumpers appear tight and I see no unusual wear...so I am still stumped.
#9
It is 75 140
Thanks for the responses...
Ok, the fluid I used was Amsoil 75/140; is this too light? Where the hell do I find 90/140?
I have been up under the thing, and I can't see anything that is loose, leafs are tight, spare is tight, bed appears to be tight. This only happens when I turn too, not on acceleration or deceleration, which I think rules out u-joints, doesn't it? I can't see or hear anything in the tailgate that would lead me to believe it is that, but I am going to get in there and grease it up anyway. Now, I have a POS ARE brand cap, that I guess could be moving around when I turn, but all the bumpers appear tight and I see no unusual wear...so I am still stumped.
Ok, the fluid I used was Amsoil 75/140; is this too light? Where the hell do I find 90/140?
I have been up under the thing, and I can't see anything that is loose, leafs are tight, spare is tight, bed appears to be tight. This only happens when I turn too, not on acceleration or deceleration, which I think rules out u-joints, doesn't it? I can't see or hear anything in the tailgate that would lead me to believe it is that, but I am going to get in there and grease it up anyway. Now, I have a POS ARE brand cap, that I guess could be moving around when I turn, but all the bumpers appear tight and I see no unusual wear...so I am still stumped.
#10
http://www.fordproblems.com/tsbs/F-150/2004/ Try this. Its a paid deal but here is another
http://www.ford-trucks.com/tsbs/?tsb...tsbmodel=F-150 also you can google anything on the internet.
http://www.ford-trucks.com/tsbs/?tsb...tsbmodel=F-150 also you can google anything on the internet.
Last edited by ceasefire49; 09-27-2016 at 10:54 AM.