2003 rear end whine while on the gas.

[GreenEyez]

Title pretty much says it all when I am at highway speeds and have my foot on the gas even if it's just to keep a constant pace I hear a light rear end whine. As soon as i let go though it dies down and I can't hear it. Just want to know whats happening if this will develop into a bigger problem or what.

 

[NJExplorerFan]

This is a common issue with Gen III Explorers. It's called the infamous rear end hum/whine. If you do a search, you'll see plenty of posts on it. Basically, it can be repaired with a kit since Ford issued a Technical Service Bulletin on it. But, it's pretty costly since it involves replacing the entire rear end differential and adding thicker fluid.

You may want to try just adding the thicker fluid and see if it helps. I may try that as well.

 

[ericautopart]

I've got the whole kit for $155.00. Includes ALL bearings and seals updated as per Ford's TSB.

 

[RickM]

I've got the whole kit for $155.00. Includes ALL bearings and seals updated as per Ford's TSB.

But needs to be done at a shop equipped to do this type of work....correct?

 

[thepotroast]

I've got the whole kit for $155.00. Includes ALL bearings and seals updated as per Ford's TSB.

What about the worn ring and pinion which is also indicated in the TSB to be replaced by Ford? Is that included for $155 too....because that's what Ford serviced under my repair at 60k miles and that's what the TSB calls out. let's not forget the $500-$800 in labor it will cost a shop to rebuild the differential, using your parts....more if they choose not to.

I'm not trying to be rude here, but it's easy to sell just the parts to the problem, but that doesn't really take care of the issue.

I have an 85 Mercedes Diesel sedan I am rebuilding right now, that has no A/C. I have the $400 in parts sitting in my shop, but it's going to be about $1200 for everything to be installed and charged....

To the OP....try the easiest tip first. Drain your rear diff fluid completely, and refill it with a full sythetic 75w-140 lube. I suggest Royal Purple or Lucas. I used Mobil1 and that did not work for me...I drained it and put in Royal Purple and that quieted it down. If you have a limited slip differential, you will need to add an additional 6oz of friction modifier to the lube.

 

[ericautopart]

But needs to be done at a shop equipped to do this type of work....correct?

If you aren't able to do it yourself, yes. You'll need a bearing press and such to be able to do it yourself.

No, ring and pinion isn't included.

 

[GreenEyez]

Ok Im going to try putting in the oil you suggested should I just do the front end while I am at it or does it not matter? If I don't do this am I looking at allot of damage to my rear end or is it strictly just an annoyance.

btw guys thanks for sending help in mass haha you guys are awesome I love these forums.

 

[thepotroast]

Ok Im going to try putting in the oil you suggested should I just do the front end while I am at it or does it not matter? If I don't do this am I looking at allot of damage to my rear end or is it strictly just an annoyance.

btw guys thanks for sending help in mass haha you guys are awesome I love these forums.

It's just an annoyance, not a ticking time bomb. The new fluids may quiet it down some. You need to find out if you have the limited slip differential. Post up your axle code (or just complete VIN)....if you do have a limited slip diff, you need to add the extra friction modifier. If you don't, you don't need to.

The front end uses 75w-90 fluids. How many miles does your truck have? Your diff fluids should be serviced in regular intervals just like any other components on the truck. If your truck has over 60k miles and the fluids have not been serviced in the diffs, then you need to change them anyway. If you aren't the original owner and just aren't sure....change ALL of the fluids in the truck.

 

[GreenEyez]

Yea Its 73800 around I think. I'm not sure if the fluids have been changed but when I bought the truck I changed the oil all pads and rear 2 rotors. I'll have to get the vin so I can figure out about my rear axle.

 

[muzzymaniac]

Stealin the thread for a minute.... Royal Purple bottles claim to have an anti-friction additive built in. Here's the excerpt from the website..


Max-Gear is an ultra-tough automotive gear oil. It’s designed to maximize power and provide unsurpassed protection to heavily loaded gears. It makes gears run smoother, quieter, cooler and longer without overhauls.

Max-Gear outperforms other gear oils because it combines the highest quality synthetic oils with Royal Purple’s proprietary Synslide additive technology.

Max-Gear is recommended for use in truck, motor home / RV, and automotive front or rear differentials, manual transmissions, and lower gear units of marine engines that specify use of an API GL-5 or GL-4 fluid. All viscosities of Max-Gear are formulated with hypoid friction modifiers necessary for use in clutch or cone type differentials. No additional additives are necessary.


I don't have an LS diff - is this still safe to run?

 

[matt0248]

Add the extra slip lock addative anyways. Use two bottles, it won't hurt anything. My 3.73 LS diff was just rebuilt. The rebuilder, s highly reputable shop whose specalizes in drivetrains, said to use two bottles of sliplock addative and Regular gear oil,, Not- ssynthetic. I am not sure the manufacturer of the gears, bearings, and clutch packs, they were not Ford parts. I Had the whine since new. The clutch packs were shuddering for two years, changing fluid did not help. Finally the chattering stopped and bearing noises developed.

 

[n2epv]

What do you folks recommend for removing the rear diff drain plug? The local auto store has some junk metal L-shaped thing for a ridiculous price.

My '04 with 64K miles gets the rear diff noise when driven on the highway in the summer. No noise at all in the winter (below 32 F). Like GreenEyez case, throttle position makes my noise come and go. Don't know about the TSB on it, but I suspect the previous owner had it apart as there is a nice bead of silicone around the back cover mating surface.

 

[NHarris]

What do you folks recommend for removing the rear diff drain plug? The local auto store has some junk metal L-shaped thing for a ridiculous price.

My '04 with 64K miles gets the rear diff noise when driven on the highway in the summer. No noise at all in the winter (below 32 F). Like GreenEyez case, throttle position makes my noise come and go. Don't know about the TSB on it, but I suspect the previous owner had it apart as there is a nice bead of silicone around the back cover mating surface.

Here's your solution:

Replace the ring and pinion gear and the convential axle grease with synthetic axle grease.

ok, being that i repaired these all the time and enjoyed doing it i will tell you what the problem is and how it is fixed, if it comes back it was because someone did not install the r & p correctly.

the problem is that the pinion bearings were not pressed on all the way, therefore, after time it moves and the gears start to whine, The repair is to replace all the bearings and ring and pinion, this is very easy to mess up. as some of you know if you overtighten the pinion bearing it will whine, this is probibly what most techs do, its only supposed to be 15-20in lbs drag. this is why alot are nto getting fixed, of the many ive done none have comeback, nor have any of the many my team leader rebuilt have come back, other techs in the shop HAVE had problems. but i was trained by my team leader and he is very meticulous and likes suspension and axle work so i was taught right, but most arent. therin lies the problem. but that IS the fix for the rear axle howl/whine

Thats from another thread on this site
2003 Ford Explorer Rear Differential Whine

 

[PDUBYA]

What do you folks recommend for removing the rear diff drain plug? The local auto store has some junk metal L-shaped thing for a ridiculous price.

I used a hex head bolt the same size as the plug recess. I don't know the size by memory. I had to lightly file 2 of the opposite points to get a snug fit then, after inserting it into the recess turned the threaded end with a pipe wrench. Wally World sells a pump set used for oil, gas etc. A must for getting the new oil in since there is not enough room to tip a bottle.

 

[PDUBYA]

Stealin the thread for a minute.... Royal Purple bottles claim to have an anti-friction additive built in. Here's the excerpt from the website..

Royal Purple caused my newly installed reman diff to shudder when making slow right turns. I drained it and added Ford synthetic and the Ford additive and the shudder went away. Surprisingly, the Ford oil and additive from the dealer cost less than the Royal Purple did from the local auto parts store.