High Mileage Lubricants.

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D

DuxTom

Joined
Apr 22, 2018
Threads
8
Messages
60
Location
Missoula, Montana
Evening all,

After owning several, I’ve been without an FJ now for FAR to many years, however recently acquired a high mileage stock drivetrain ‘78 40. I’ll have many questions as I ease back into this world and attempt to recall details long forgotten about the species and will most likely rely heavily on the immense hive brain that is IH8MUD and I thank you all greatly in advance.

First and foremost… lubricants? As I’ve mentioned it’s high mileage (154k+).

Motor: Previous owner was using a 10w-30 in Winter and 10w-40 in Summer “synthetic blend”… synthetic of any sort in these old motors seems like maybe not the best idea? Thoughts/Recommendations?

Gear oils: Transmission? TCase? Differential?

Coolant: Any considerations here or just as straightforward as it should be?

Manuals: Are the factory reprints decent?

I’ll start there. Thanks again!

Tom
 
Resources tab at header of website for all the (FSM) factory service manuals.

GL-4 gearoil for the transfer / transmission / differentials. 90 weight.

Toyota genuine red anti-freeze or the other stuff that's green, 75 /25 mix for the coldest Montana temps. (if you plan to drive during the winter).

T4 Rotella engine oil in the 5w-40 flavor is what I've run for many years in the 2F. Real dino oil, not synthetic. Verify ZDDP content.

:cheers: (and the official welcome to the mudness: :flipoff2: )
 
i wouldnt consider that mileage high mileage, but,
i use T5 sythetic blend engine oil
you can buy zddp additive seperate for the engine oil as well
 
micruz60 said:
T4 Rotella engine oil in the 5w-40 flavor is what I've run for many years in the 2F. Real dino oil, not synthetic. Verify ZDDP content.
Click to expand...
Thanks… did you mean T4 15w-40? I’m not seeing a 5w-40 in the T4. Only a Rotella 5w-40 in the fully synthetic T6. Additionally which zddp additive do you like and how much? Thanks!!!
 
I use dino lubricants. I don't think synthetic was around when these things were made. Adding additives is beyond my scope. I run Rotella 15-40 in most of my flat tappet sbc's. I have one sbc that wants me to run 20-50 which has the proper old school zinc in it. I think it's valvoline. The trans and tcase gets 80-90 straight GL4 to keep the yellow parts happy. GL4 or GL5 in the diffs. I hate keeping multiple type of gear lube.
 
have since learned adding zddp additive isnt always best as you dont know if it is going to mess with your oils chemistry
get an oil with the wear pack you like already in it
 
Offered as another datapoint, I run Rotella T6 full synthetic in my 79 desmogged 2F.

When I researched it a couple of years ago, T6 had sufficient zinc for flat tappet engines. And its detergent qualities seemed like a good idea for my 2F that had been sitting for years before it sputtered back to life.

I also run T6 in my diesel tractor, which makes it convenient. It's also readily available locally, and priced well.

So far, so good!
 
Last edited:
DuxTom said:
First and foremost… lubricants? As I’ve mentioned it’s high mileage (154k+).

Motor: Previous owner was using a 10w-30 in Winter and 10w-40 in Summer “synthetic blend”… synthetic of any sort in these old motors seems like maybe not the best idea? Thoughts/Recommendations?
Click to expand...
Whatever is on sale...
But I use the big oil filter and usually throw in a zinc of some sort

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I think synthetic cleans out old stuff way too good and thus kills them. If I ever got a new unit I would run synthetic after break in oil. Running Shell 15-40
 
I will stay away from the motor oil debate. Redline Synthetic MT90 in the transmission, Redline Synthetic 75W90 in the diffs, and either one in the transfer case. The MT90 is a GL4 lubricant. As already mentioned, stay with a GL4 spec in the transmission. Apparently the brass/bronze synchros don't like GL5 spec gear oil.
 
Lake Speed Jr formulates and test oils. He has several videos on this topic. Lack of ZDDP was an issue, but the oil labs solved that long ago. Anything you can buy is better than the old stuff. With these old engines I figure the most important thing is they get oil changes often if you’re not going to pull a sample. Three of his videos linked below. He has many more.



Do Classic Cars (1951-1996) Actually NEED Special Oil? - https://youtu.be/a3uXSI9wQv8
 
I’m doing an oil change this week, going with the 20w-50 Lucas conventional oil based off what I read here on mud. (looks like it has really high ZDDP). Came down to that or VR1, we’ll see how it goes.

This thread reminds me I need to look at the transmission/T case/diffs, been putting that off
 
procomsignathid said:
I’m doing an oil change this week, going with the 20w-50 Lucas conventional oil based off what I read here on mud. (looks like it has really high ZDDP). Came down to that or VR1, we’ll see how it goes.

This thread reminds me I need to look at the transmission/T case/diffs, been putting that off
Click to expand...
Thanks! Which VR1 were you eyeballing? 10w30? Good temperature range I guess… but maybe a little thin for the hotter summer days? I’ll take a dive into the Lucas 20w50. Thanks.
 
I have to think that the quality of lubricants are significantly improved today vs the rollout dates of our 40's and 55's. I'm not particular but have been running synthetic motor oils for a decade or so with no signs of trouble. I'm in TX and its hot but never go higher than a 10-40 wt oil. I am particular with my filter selection and have ditched all WIX oil filters after reading the woes of multiple lost engines in the 80's section due to faulty backflow valves (oil starvation). I've had no issue with the smaller YZZD filters for less than $5 a pop, but will sometimes use a Motorcraft FL-1A if the price point is reasonable
 
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