I have a 2002 Ford Explorer. It had loud rear gear noise when I purchased it several years ago. I took it to the Ford dealer. The service manager said that he owned the same year and model and that it is just how they are going to sound...that he could fix it but that the gear noise would come back. I took it to a driveline shop and they rebuilt the unit and the sound was 99% gone. Now I'm hearing some moderate gear noise again from time to time. Sometimes it goes away. It is more pronounced when driving on windy roads. I understand that many late model Ford limited slip differentials have this problem. I'm wondering if anyone has found a solution using Amsoil or Redline or some other high end fluid. I have been having Ford change it every year or so at high cost, which includes their factory synthetic fluid and friction modifier. I had Jiffy lube do it once, but there didn't seem to be any difference. Amsoil says that their fluid doesn't need friction modifier, but that they have one in the case it is needed?! That seemed strange, but I'm thinking I need it all, if a fluid would make a difference. Anyone have experience with this?
Limited Slip differential noise
- Thread starter TahoeSkiBum
- Start date
- Status
I requested this be moved to the ATF, differential section.
Tahoe, how many miles since you last had it changed? Do you know what weight gear oil they used?
Tahoe, how many miles since you last had it changed? Do you know what weight gear oil they used?
Sorry if I didn't post in the right place. I'm new and still finding my way around the site. I think it has been about 15,000 to 20,000 since the last fluid change. I may call the dealer and ask him to check the record. The factory fluid is synthetic and supposed to last longer than that, but I have my doubts. The fluid is 75-140 weight.
Well, the Motorcraft 75W-140 is a very good fluid, as is the Amsoil Severe Gear. Most all gear oils now have some limited slip additive in them, but sometime you have to add extra, depending on the application. I would think the Motorcraft fluid should last longer than 20K. I have a partial synthetic in my Jeep differentials and I don't plan on changing it for at least 60K or longer. Make sure the dealer is actually using the Motorcraft fluid and not some cheap fluid to save them money.
No problem on posting in the wrong place. I still do it from time to time. Anytime you need a post moved, just click on the Notify tab and ask the mods to move it and they will.
No problem on posting in the wrong place. I still do it from time to time. Anytime you need a post moved, just click on the Notify tab and ask the mods to move it and they will.
Is it gear noise or a noise from the clutches? You might try replacing the oil with oil that has the special additive. Thats cheap and easy to do before you go tearing the rear end apart.
I'm not sure if it is gears or clutches. I would guess clutches. It is kind of a droning sound like loud tires. The sound often comes when the truck is first run from cold and also after driving on windy mountain roads. The sound seems to be reduced when driven on the open highway in a straight line.
I think Ford sells the special additive in a bottle. I picked the stuff up when I changed my gear oil in my Marauder. I think it is called Motorcraft Limited Slip Differential Additive.
I have a bottle in my garage that I picked up at the Ford Dealer.
I have a bottle in my garage that I picked up at the Ford Dealer.
The limited slip additive is friction modifier. It prevents the clutches from sticking and grabbing. When acting up, it isn't subtle, but it is more of a feel than a noise. The differential is very jerky on turns. In extreme cases, you will get a loud bang noise though, loud enough to make you think something broke.
This really doesn't sound like what the OP is chasing.
Fresh fluid may help a little, and certainly won't hurt, but most such noises won't go away without an overhaul. Sometimes it doesn't. Fortunately, most such noises are just an annoyance, and have little to do with durability.
This really doesn't sound like what the OP is chasing.
Fresh fluid may help a little, and certainly won't hurt, but most such noises won't go away without an overhaul. Sometimes it doesn't. Fortunately, most such noises are just an annoyance, and have little to do with durability.
I had an 02 Explorer and had the same issue. Ford rebuilt the rear end (clutch packs). Started making the same noises again when I traded it in. Had the tranny worked on twice. Too bad, I liked driving that rig. Nice handling, adequate power.
Last edited:
I have a 2 friends that are Ford specialists. They both told me that those gears almost always whine, but they last for ages.
One of those friends got a used noisy Explorer IRS LSD gear from a dealer for free. He then swapped out the open diff from his wife's IRS Explorer.
Perhaps the only solution is a premium ring and pinion from a racing gear specialist?
One of those friends got a used noisy Explorer IRS LSD gear from a dealer for free. He then swapped out the open diff from his wife's IRS Explorer.
Perhaps the only solution is a premium ring and pinion from a racing gear specialist?
I have the LS Rear and used a synthetic gear oil that said no additives were required for LS rears. My suggestion is go to Ford buy the additive and then use a good snthetic gear oil spec'd for your vehicle. That's what I did and I have no noise to speak of coming from the rear. OTOH I've had them that made noise and never failed. My feeling is the one size fits all mentality for gear oil is not necessarily the best, and the additive in this case is necessary. JMO
Ring & Pinion parts:
http://www.ringpinion.com/PartsList.aspx...ub-Differential
Spider gears:
http://www.ringpinion.com/PartsList.aspx...ub-Differential
For a very high quality differential gear oil at a fair price, take your own gallon jug to a truck repair shop that has a drum of the Eaton-warranty approved synthetic gear lube...either xW-90wt or xW-140 wt as your differential requires. Buy a gallon, have any local quick lube change the gear oil, add the friction modifier additive, and you've done the best you can do. If 80W-90 is OK, see if one of our Schaeffer reps can sell you some quarts of Schaeffer's great #267 gear lube with moly in it plus sticky stuff that makes it cling to the gear teeth until warm...LSD add is already in this. I don't worry about the difference between 75W and 80W gear oil except in frigid climates...not Tahoe.
Demar, the limited slip additive is only for friction clutch type LSDs, and is already in most differential gear oils. More is not better unless really needed. In any case, the problem originally described is not a problem of the clutches grabbing.
http://www.ringpinion.com/PartsList.aspx...ub-Differential
Spider gears:
http://www.ringpinion.com/PartsList.aspx...ub-Differential
For a very high quality differential gear oil at a fair price, take your own gallon jug to a truck repair shop that has a drum of the Eaton-warranty approved synthetic gear lube...either xW-90wt or xW-140 wt as your differential requires. Buy a gallon, have any local quick lube change the gear oil, add the friction modifier additive, and you've done the best you can do. If 80W-90 is OK, see if one of our Schaeffer reps can sell you some quarts of Schaeffer's great #267 gear lube with moly in it plus sticky stuff that makes it cling to the gear teeth until warm...LSD add is already in this. I don't worry about the difference between 75W and 80W gear oil except in frigid climates...not Tahoe.
Demar, the limited slip additive is only for friction clutch type LSDs, and is already in most differential gear oils. More is not better unless really needed. In any case, the problem originally described is not a problem of the clutches grabbing.
Last edited:
Good to know, mine felt a little funny going around turns after a change a few years back. I was told no additive was needed. I bought the additive put it in and solved the problem. My vehicle is an 88 so maybe that was the issue. 30,000 miles later no problems.
- Joined
- Dec 30, 2006
- Messages
- 29,558
I had someone tell me they use this stuff in their rear diff to quiet down their rear diff whine called Justice Brothers Gear Oil Treatment. I`ve never seen it and have no idea what it is exactly.
Thanks for the feedback. Anyone used the Justice Brothers Gear Oil Treatment noted above? I always get leary of additives with big claims to fix things. I'm still wondering if Amsoil gear oil might quiet things down. Anyone experienced the Amsoil or other premium gear oil actually correcting noise? I have noticed engines that sound much smoother / quieter with one brand of oil over another. I have had the unit rebuilt once, tried two brands of synthetic gear oil including Jiffy Lube and Motorcraft with the friction modifier, but there is still the inconsistent noise. Curiously, Ford service people say to live with it.
Here is a page with the Justice Brothers gear oil additive:
http://www.justicebrothers.com/pages/products/products_carcare_trans_additives.htm
But again, I am afraid to use anything other than a good brand of gear oil, and, if required, OE limited slip additive.
http://www.justicebrothers.com/pages/products/products_carcare_trans_additives.htm
But again, I am afraid to use anything other than a good brand of gear oil, and, if required, OE limited slip additive.
The limited slip is not being used when just driving straight - when cruising.
So your noise is from the gears, or possibly bearings.
I used to set up differentials for AMG Mercedes, and it is tricky to get everything aligned right and with the proper preload.
If you yank the cover, a pro can tell by the pattern on the gear teeth, and check the bearings.
Let him drive it first.
So your noise is from the gears, or possibly bearings.
I used to set up differentials for AMG Mercedes, and it is tricky to get everything aligned right and with the proper preload.
If you yank the cover, a pro can tell by the pattern on the gear teeth, and check the bearings.
Let him drive it first.
- Status
Similar threads
