Yup, 80-90 in my front , tcase, and rear diff. Couldnt find a gallon of 75-90 ANYWHERE. Been over a year and its fine. I use Valvoline to be specific. It's kinda like 10w-30 instead of 5w-30 motor oil. You will be fine with 80w-90
rear diff fluid question
- Thread starter Army97
- Start date
Yup, 80-90 in my front , tcase, and rear diff. Couldnt find a gallon of 75-90 ANYWHERE. Been over a year and its fine. I use Valvoline to be specific. It's kinda like 10w-30 instead of 5w-30 motor oil. You will be fine with 80w-90
pluton
Senior Member
All the shops that deal with Toyota trucks, that I've seen, just keep the 80W-90 in stock.
I've used the 75W-90 syn GL-5 (they don't make 75W-90 in conventional, do they? EDIT: Yes, apparently they do)) in previous Toyota trucks/Land Cruiser differentials without incident.
GL-5 for diffs, GL-4 for transmissions.
I've used the 75W-90 syn GL-5 (they don't make 75W-90 in conventional, do they? EDIT: Yes, apparently they do)) in previous Toyota trucks/Land Cruiser differentials without incident.
GL-5 for diffs, GL-4 for transmissions.
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pluton
Senior Member
Totally OK forever.
Thoughts and Ideas Please
For those that have changed their own rear differential oil, what does your old oil look like when examined closely?
I’ve had a history with my 1998 4Runner 4WD rear differential and I’m trying to determine if I went too long (50,000 miles) between oil changes using Lucas Heavy Duty High Performance 80W-90 gear oil.
I just changed my rear oil and found it to be somewhat dirty (very dark grey color) and it had the all too familiar metallic look which appeared to be very fine metal dust in the oil. There were no large metal pieces in the oil or on the drain plug but the plug did have the typical metal dust residue.
Here is the history of the vehicle:
134,700 miles – vehicle purchased used.
138,000 miles – changed oil in both differentials and transfer case. Technician that did work said oil was very dirty in rear differential and he didn’t think it had been changed since the vehicle was new. Used conventional Valvoline 80W-90 oil.
177,000 miles – noticed a loud moan or hum will driving at interstate speeds but could not find the source.
180,000 miles – changed rear differential oil for 2nd time and used Mobile 1 synthetic 75W-90 oil.
192,000 miles – noise was louder than ever and determined carrier bearings was defective.
193,000 miles – installed Jasper re-manufactured differential ($2,300).
198,000 miles – after 5k mile break in period as directed by Jasper, changed rear differential oil and installed Lucas Heavy Duty High Performance 80W-90 oil. Wish now had gone with first instinct and used Mobil 1 but went with Lucas in effort to get as close to Toyota recommended oil weight.
I originally thought the reason the differential failed was due to using the wrong weight oil, but now wonder if maybe the 2 different oil changes I performed cleaned out the build up and that resulted in the carrier bearing failing.
Now with the oil being dirty again, it has seriously crossed my mind to never change it again and just check the oil level from this point until I eventually sell it (as this is what I have found in the recommended Toyota maintenance schedule).
Yes, to not change the oil goes against all that has been learned about vehicle preventive maintenance, but I do not want to spend ANOTHER 2k or more on the rear differential.
Anyone have any experience and/or thoughts they would like to share?
Thanks in advance!
For those that have changed their own rear differential oil, what does your old oil look like when examined closely?
I’ve had a history with my 1998 4Runner 4WD rear differential and I’m trying to determine if I went too long (50,000 miles) between oil changes using Lucas Heavy Duty High Performance 80W-90 gear oil.
I just changed my rear oil and found it to be somewhat dirty (very dark grey color) and it had the all too familiar metallic look which appeared to be very fine metal dust in the oil. There were no large metal pieces in the oil or on the drain plug but the plug did have the typical metal dust residue.
Here is the history of the vehicle:
134,700 miles – vehicle purchased used.
138,000 miles – changed oil in both differentials and transfer case. Technician that did work said oil was very dirty in rear differential and he didn’t think it had been changed since the vehicle was new. Used conventional Valvoline 80W-90 oil.
177,000 miles – noticed a loud moan or hum will driving at interstate speeds but could not find the source.
180,000 miles – changed rear differential oil for 2nd time and used Mobile 1 synthetic 75W-90 oil.
192,000 miles – noise was louder than ever and determined carrier bearings was defective.
193,000 miles – installed Jasper re-manufactured differential ($2,300).
198,000 miles – after 5k mile break in period as directed by Jasper, changed rear differential oil and installed Lucas Heavy Duty High Performance 80W-90 oil. Wish now had gone with first instinct and used Mobil 1 but went with Lucas in effort to get as close to Toyota recommended oil weight.
I originally thought the reason the differential failed was due to using the wrong weight oil, but now wonder if maybe the 2 different oil changes I performed cleaned out the build up and that resulted in the carrier bearing failing.
Now with the oil being dirty again, it has seriously crossed my mind to never change it again and just check the oil level from this point until I eventually sell it (as this is what I have found in the recommended Toyota maintenance schedule).
Yes, to not change the oil goes against all that has been learned about vehicle preventive maintenance, but I do not want to spend ANOTHER 2k or more on the rear differential.
Anyone have any experience and/or thoughts they would like to share?
Thanks in advance!
Sean K.
New member
Dark grey? Usually, cement colored grey oil indicates water intrusion. Done any deep water crossings (or driving on flooded streets)? Any time you go over hub deep, you should really check the diff oil to see if water has gotten in. Do I do that? Nope. I should, but I'm lazy. But if I submerge the entire axle, then I'll take a peek.
It's not very expensive ($30 or so) to send in a sample of your oil to a lab for analysis. They'll tell you what metals and other contaminants are in the oil. Blackstone Labs is one I've used. Google them for info, and if you send them an email they'll send you a free sample container. You fill it and send it back with your payment and they'll send you the results. Might give you some peace of mind, or info about what needs attention.
mtbtim
Elite Member
ricofreako
New member
75w-90
pluton
Senior Member
50K miles is fine, IMO, for trans/transfer(espec. w/ syn), and the front diff if the front diff is rarely used. But the rear diff oil is arguably the hardest working gear oil in the truck and should be changed every 10-12K, or every 1 or 1.5 years or so. If it is that dull grey color, you waited a bit too long. YMMV...
Thank you for your input Pluton. I also think I may have gone too long between changes and may have done some permanent damage to the rear differential. I also agree with you that 50k interval for the transfer case and front differential using synthetic oil is acceptable, depending on how often the 4WD is used.
But after replacing the rear differential at 193k, I thoroughly searched through all the Toyota maintenance documents I could find, and for normal use—NOT Special Conditions use— I could find no suggested frequency for the rear differential oil change; just check the oil level and add if needed. If someone has some documentation from Toyota recommending something otherwise, please refer me to it.
I also recently searched this forum and have found several references to 50,000 mile intervals between rear differential oil changes. See further back in this forum and this 2nd forum for comments of 50k: http://www.toyota-4runner.org/3rd-gen-t4rs/107443-rear-differential-fluid.html Maybe their comments meant transfer and front differential intervals of 50k, but their posts were in forums for “Rear Differential”.
As I stated in my original post yesterday, I changed the oil at 137,000 and the tech said he didn't think it had ever been changed. Not long after, a hum developed in the rear differential. I changed the oil a 2nd time (about 45k again, following the 50k routine) and then the carrier bearing failed. So maybe the possible 137k mileage on the original rear differential oil is what did the permanent damage. Again, I’m speculating that it was the original oil. I don’t know that as fact.
If the rear differential begins to hum again after my most recent oil change (as it did before on the original), I’m not going to change it ever again and just live with the low hum. A one-time investment of $2,000+ into the rear differential is acceptable to me. I don’t think I can stomach (wallet) another one.
I thoroughly document all my service on this vehicle and I went back and reviewed my notes when the rear diff was replaced at 193k and found my previous entry regarding the low hum. These notes are now proving their worth for future service (or not to service).
One of the issues I struggled to find an answer to after replacing the rear diff with the remanufactured one was the proper oil to use. When I replaced it, I wanted to put in Toyota recommend oil which was 90w for my 1998 4Runner. Well no one sold 90w that I could find. Finally, after several emails from Toyota, they did admit that 75w – 90 was acceptable. I went with Lucas Oil (80w – 90) because it was as close as possible to the original Toyota oil weight. I wish now I had not and gone with 75w – 90 Mobil 1 synthetic because it lasts longer and does a better job of lubricating.
So if anyone reading this is on the fence about synthetic, I strongly recommend it. And yes, I know, there is the school of thought that for worn engines and other devices, synthetic can increase oil consumption, use, and/or leaks because it cleans and opens small leaks into larger leaks. But OVERALL, it is a much better oil. Period. No matter the grade. So if you want better protection and longevity of oil, use it! I did put synthetic into my rear differential this time, so maybe that will help and possibly stave off any permanent damage. Time will tell.
For anyone reading this, for REAR DIFFERENTIAL oil change service intervals (not transfer case or front differential), from my experience, I would recommend 15K – 30k miles using a synthetic gear oil. Again, I’m partial to Mobile 1 75w – 90.
If my rear differential gives no problems (i.e.: no hum or noise), I will probably change the oil at 15k. I will try and give an update so others can learn and not make the same mistake I made.
I don’t mean to belabor this point but I’m a working man and cannot afford another vehicle every 5-10 years. I have to maintain them and get 20+ years of service before I purchase another (i.e.: used, NOT brand new). The only way to increase the life of a device is preventive maintenance. While some may think it costs money, I’m of the camp it saves money over the life of the vehicle as well as increasing its re-sale value.
If anyone has any other suggestions or comments, I’m all ears. But I’m now of the opinion 50k is simply too long for the rear differential oil change interval, especially if the oil is conventional. 15k intervals is more reasonable going no higher than 30k if using synthetic oil. 50k may be acceptable interval, but for synthetic oil only, NOT conventional. If anyone has experience with 30k to 50k intervals on synthetic oil, please post and give your experience and thoughts. Again, to clarify, this is for the rear differential only, NOT transfer case or front differential.
Thanks again for all the comments everyone.
But after replacing the rear differential at 193k, I thoroughly searched through all the Toyota maintenance documents I could find, and for normal use—NOT Special Conditions use— I could find no suggested frequency for the rear differential oil change; just check the oil level and add if needed. If someone has some documentation from Toyota recommending something otherwise, please refer me to it.
I also recently searched this forum and have found several references to 50,000 mile intervals between rear differential oil changes. See further back in this forum and this 2nd forum for comments of 50k: http://www.toyota-4runner.org/3rd-gen-t4rs/107443-rear-differential-fluid.html Maybe their comments meant transfer and front differential intervals of 50k, but their posts were in forums for “Rear Differential”.
As I stated in my original post yesterday, I changed the oil at 137,000 and the tech said he didn't think it had ever been changed. Not long after, a hum developed in the rear differential. I changed the oil a 2nd time (about 45k again, following the 50k routine) and then the carrier bearing failed. So maybe the possible 137k mileage on the original rear differential oil is what did the permanent damage. Again, I’m speculating that it was the original oil. I don’t know that as fact.
If the rear differential begins to hum again after my most recent oil change (as it did before on the original), I’m not going to change it ever again and just live with the low hum. A one-time investment of $2,000+ into the rear differential is acceptable to me. I don’t think I can stomach (wallet) another one.
I thoroughly document all my service on this vehicle and I went back and reviewed my notes when the rear diff was replaced at 193k and found my previous entry regarding the low hum. These notes are now proving their worth for future service (or not to service).
One of the issues I struggled to find an answer to after replacing the rear diff with the remanufactured one was the proper oil to use. When I replaced it, I wanted to put in Toyota recommend oil which was 90w for my 1998 4Runner. Well no one sold 90w that I could find. Finally, after several emails from Toyota, they did admit that 75w – 90 was acceptable. I went with Lucas Oil (80w – 90) because it was as close as possible to the original Toyota oil weight. I wish now I had not and gone with 75w – 90 Mobil 1 synthetic because it lasts longer and does a better job of lubricating.
So if anyone reading this is on the fence about synthetic, I strongly recommend it. And yes, I know, there is the school of thought that for worn engines and other devices, synthetic can increase oil consumption, use, and/or leaks because it cleans and opens small leaks into larger leaks. But OVERALL, it is a much better oil. Period. No matter the grade. So if you want better protection and longevity of oil, use it! I did put synthetic into my rear differential this time, so maybe that will help and possibly stave off any permanent damage. Time will tell.
For anyone reading this, for REAR DIFFERENTIAL oil change service intervals (not transfer case or front differential), from my experience, I would recommend 15K – 30k miles using a synthetic gear oil. Again, I’m partial to Mobile 1 75w – 90.
If my rear differential gives no problems (i.e.: no hum or noise), I will probably change the oil at 15k. I will try and give an update so others can learn and not make the same mistake I made.
I don’t mean to belabor this point but I’m a working man and cannot afford another vehicle every 5-10 years. I have to maintain them and get 20+ years of service before I purchase another (i.e.: used, NOT brand new). The only way to increase the life of a device is preventive maintenance. While some may think it costs money, I’m of the camp it saves money over the life of the vehicle as well as increasing its re-sale value.
If anyone has any other suggestions or comments, I’m all ears. But I’m now of the opinion 50k is simply too long for the rear differential oil change interval, especially if the oil is conventional. 15k intervals is more reasonable going no higher than 30k if using synthetic oil. 50k may be acceptable interval, but for synthetic oil only, NOT conventional. If anyone has experience with 30k to 50k intervals on synthetic oil, please post and give your experience and thoughts. Again, to clarify, this is for the rear differential only, NOT transfer case or front differential.
Thanks again for all the comments everyone.
Pyral
Member
Probably not, the additive is for limited slip differentials that use clutches. The elocker isn't a limited slip, there isn't a clutch in it.
