17' 4RUNNER 75w90 Synthetic or Conventional?

[dedonderosa]

So ive been reading mixed views on gear oil. im looking to change out the front and rear diff on my 17 4Runner with locking rear diff. now my main concern is to go synthetic or conventional gear oil. ive read that synthetic looses its viscosity at higher temps, and that conventional is an overall better choice for the ring and pinon. dont shoot the messenger just telling you what i have come across. just wanted to get some opinions on you guys think i should run in the 4R. i was originally looking to purchase 75w90 Valvoline Synpower which is on sale at Advance for $10/qt. thanks guys lmk what you think

 

[supton]

Are you towing? Or off-roading? If towing, go for the high zoot stuff. Off-road and I'd be using what is cheaper--under the impression that you'd be changing more often due to possible water contamination.

I'm not sure I'd over think it if not doing either. Just find what meets specs. Most of these parts go "forever" on original oil, at least in pedestrian usage.

 

[JeffKeryk]

I am servicing our GS with Red Line 75w85, as that's the viscosity called for. You don't do it very often.
Good luck.

 

[dave1251]

Your changing it which is more than what most owners do. Buy on price a store brand "synthetic" cost much less and works just as well in the real world.

 

[Chris142]

You can buy chevron delo synthetic for about $6/qt @ autozone. No brainer there.

 

[dedonderosa]

Originally Posted by supton
Are you towing? Or off-roading? If towing, go for the high zoot stuff. Off-road and I'd be using what is cheaper--under the impression that you'd be changing more often due to possible water contamination.

I'm not sure I'd over think it if not doing either. Just find what meets specs. Most of these parts go "forever" on original oil, at least in pedestrian usage.



no towing at the moment, mainly commuting with some off-roading here and there. Im choosing the 75w90 valvoline synpower which seems to get good reviews over the mobil1 as a lot of people state it has maide their differentials noisy in some vehicles

 

[badtlc]

Have you looked at supertech full syn 75W-90?

As for benefits of conv vs synthetic, maybe others will chime in. There used to be talk about how conventional could provide better protection in these non-extreme applications. We haven't had any good discussion about that for a while so maybe things have changed.

 

[1000MPH]

I'm sure the factory fill is top notch since there is no service interval for normal conditions. I change mine at 40k intervals and feel it's probably too soon. I do use 4WD about 200 miles/yr.
Yes, the discussion on what to use has been long and unresolved. Probably because these things don't break due to fluid choice (but they do break, see needle bearing issue T-SB-0026-15).
I've not heard the synth vs. conventional controversy since the Tacoma rear diff (?) seal problems.
I used Delvac 75W-90 which is popular with the FJ crowd. They seem to get the most from their vehicles. Some Porsche race builders like it as well. Summit Racing has the best price I've seen.

 

[dedonderosa]

have you seen the new revised TSB to replace the entire front diff now?

 

[dedonderosa]

Originally Posted by badtlc
Have you looked at supertech full syn 75W-90?

As for benefits of conv vs synthetic, maybe others will chime in. There used to be talk about how conventional could provide better protection in these non-extreme applications. We haven't had any good discussion about that for a while so maybe things have changed.



yeah this is what i was reading about but not sure.

if i choose conventional over synthetic what brand would some of you recommend? valvoline 75w90 conv or Pennzoil conventional ?

 

[rekit]

01 Tacoma TRD w/locking diff. 240K. Lots of boat ramp use, short trip (20 miles) to most ramps. refilled w 75-90 syn once, no problems.
The interesting thing i remember was someone said to always loosen the fill plug first before the drain plug. Someone drained it then could not get the fill plug open. OOPS

 

[1000MPH]

Originally Posted by dedonderosa
have you seen the new revised TSB to replace the entire front diff now?


I can't find a new TSB.

 

[dedonderosa]

sent you a pm with the new tsb

 

[umungus1122]

Originally Posted by Chris142
You can buy chevron delo synthetic for about $6/qt @ autozone. No brainer there.

The DELO 75w-90 syn for $6 is not available in the Eastern US Autozones.

 

[Whimsey]

I was under the impression that 75W-90 gear oil was only synthetic, wear as 80W-90 could be either, usually conventional though. Could be wrong

.

Whimsey

 

[Jimzz]

I have used quite a bit of supertech gear oil including the 75w-90 with good results. Its less than $6 a quart at Walmart.

https://www.walmart.com/ip/Super-Tech-Full-Synthetic-Gear-Lubricant-75W-90-1-Quart/309470123

Never seen Delo for $6 here on the east coast as said, that would be a good deal if so.

 

[BlakeB]

Originally Posted by dedonderosa
sent you a pm with the new tsb

Send it to me too, please?

 

[dedonderosa]

coming right up

 

[ARB1977]

Amsoil Sever Gear 75W90 in my Tacoma's diff. Don't tow or haul extream loads.

 

[Cup of Joe]

Originally Posted by dedonderosa
coming right up

Can I get a copy of that TSB?