Trying to prevent high mileage leaks

Status
Not open for further replies.
Joined
May 23, 2016
Messages
2
Location
Wisconsin
I recently purchased a 1999 Toyota 4Runner with over 200,000 miles, I'm in the process of changing all the fluids. I an wondering if I should stick with conventional differential oil or switch to a group V ester-based oil like Redline to keep it leak-free. I have read that ester-based oils swell seals more than other types of oils. Money is not a factor, main concern is hopefully preventing leaks. The transfer case and front diff take 75W-90, the rear diff takes 80W-90.
 
Whatever has worked for the last 17 years and 200k, is obviously compatible with the seals.
Getting creative, may be inviting trouble this late in the game.

Oh!! And welcome to BITOG, 14 years old and still a young dog.
 
Last edited:
Stick w/ conventional. If it isn't leaking, why experiment? I think it would be overkill for an old, high mileage vehicle.
 
I'm not sure about helping to prevent leaks but the Tacoma/4Runner crowd love Redline. Use their 75w90 in the front and rear differentials and their MT-90 in the manual transmission and transfer case. Hit the drain and fill bolts with some PB Blaster a few days before and make sure that you can get the fill bolts off before removing the drain bolts. Torque is 27lb for each.
 
I like Redline products, but I have mixed feelings on MT-90. I've used it in 2 different transmissions with the same results: excellent smooth shifting once the fluid is warmed up, but very notchy shifting when cold. I believe MT-90 is more of a racing oil and MTL is more of a street/daily driver oil. I have since switched to Motorcraft Full Synthetic Manual Transmission Fluid (XT-M5-QS) which is very smooth shifting whether the fluid is hot or cold, but it's very expensive.

Do I need to use GL-4 in the transfer case?
 
Originally Posted By: twincam00
Do I need to use GL-4 in the transfer case?


Your owner's manual should say. The one for my ECHO says I can use GL-4 or GL-5 in the gearbox. I would go by what the manual specifies.

And I have had mixed results with MT-90 as well, I used Amsoil the last time (sold at my local NAPA). It works great for me.
 
Originally Posted By: twincam00


Do I need to use GL-4 in the transfer case?


I beleive that the owners manual recommends GL-4 or GL-5 but the people over at Tacoma World recommend GL-4 so they use the MT-90.

I hear what you're saying about the MT-90 feeling notchy. It was a huge upgrade over the old factory fill in my 98 Tacoma but I still think that it can be better so I'll be trying the MT-85 next change.

No, you don't need the MT-90 in the transfer case you can use 75w90 but it was recommended to me because if they leak some they'll end up sharing fluid so it's best to run the same thing in both the manual transmission and transfer case.
 
75W90 are usually a synthetic fluid. I say buy the 75w90 for both where 75w90 and 80w90 are called for. That way you buy one fluid instead of two.
 
I'm using 75W90 on my 4runner all around because I can get it in bulk cheap. I don't know why they spec'ed 80W90 only on the rear diff... maybe to save costs? There's no reason why 75W90 can't be used in place and it's even an improvement.
 
Originally Posted By: twincam00
I like Redline products, but I have mixed feelings on MT-90. I've used it in 2 different transmissions with the same results: excellent smooth shifting once the fluid is warmed up, but very notchy shifting when cold. I believe MT-90 is more of a racing oil and MTL is more of a street/daily driver oil. I have since switched to Motorcraft Full Synthetic Manual Transmission Fluid (XT-M5-QS) which is very smooth shifting whether the fluid is hot or cold, but it's very expensive.

Do I need to use GL-4 in the transfer case?


There is a big viscosity difference between MT90 and MTL. I tried MT90 and likewise found it great in summer, and unusable in winter. MTL is a decent tradeoff--but I'm (somewhat) tempted to use MT90 in summer, MTL in winter.
 
Status
Not open for further replies.
Back
Top