A745 Oil Type

[64D100Poly]

Hello, I’m at 10,000 mile interval to change trans oil. Manual says type “A” ATF?? From my research people use a few different types of oil, right now it has gear oil, what do some of you guys run in yours? I’m in PNW so temp averages between 20s to 90s throughout the year.


Also what do you run in the diff (8 3/4)? Manual says SAE 90

[martincom]

Well, while my daughters accuse me of being as old as dirt, 1964 was a bit before my entry into the automotive world. I'm wondering if it was before the advent multi-viscosity lubricants? Straight SAE90 is a bit on the stiff side for cold temperatures. If you've never changed your differential lube, I'd maybe give some thought to drawing it all out, with a hand drawn suction tube (similar to a grease gun in appearance), aka: siphon gun and replacing it with a multi-viscosity, such as SAE 75-90. Do this just after driving, so the fluid is warm and flows better. Alternatively, you can add a drain plug to the axle housing.

http://www.sweptline.com/tech/drainplug.html

https://www.motortrend.com/how-to/mopp- ... l-housing/

Considering the service manual specified ATF as the transmission lubricant, substituting it with gear oil creates some concern. First would be cold weather usage both in terms of operation and thee added stress of moving what would be a near grease like consistency. I'd check ahead to the latest year that transmission was utilized and see what are specifying.

I wouldn't be afraid to utilize ATF. They still use ATF as a lubricant in a gear case. My 2015 Jeep Grand Cherokee specifies ATF for the transfer case.

[BigBlockTrucks]

In addition to what martincom said,I would go with dex VI if it’s in the budget. The six speed manual in my car has a tag on it that says use dex II E only. After many conversations and advice I found the VI is backward compatible for all dextron atf and is full synthetic.
I run synthetic oils in everything unless it is an engine with a rope seal for a rear main.
Must be humans are better than dinosaurs at making stuff for oils. LOL

[Wildergarten]

I run synthetic oils in everything unless it is an engine with a rope seal for a rear main.

One wonders if one still needs the ZDDP with a synthetic for the cam and tappets, or even if it those additives are compatible with the synthetic. I think I may give a call to the folks at Amzoil, as they're pretty helpful with information like that.

[nutz]

yeah i agree with synthetics in everything
i would run 75w140 in the rear ( something that old i'm sure is worn in )and dex v or vi to replace any atf and run it 50k
just stay away from lv
if its a posi might need friction additives
what you need is lead additives to your fuel for the valves

[martincom]

One wonders if one still needs the ZDDP with a synthetic for the cam and tappets, or even if it those additives are compatible with the synthetic

Perform a browser search on ZDDP. I came across an article/chart that discussed it and the oils that still have it. I posted links to it a month or so ago, but it was in a post that wasn't related to the subject of the thread.....and I can't remember which one it was.

[64D100Poly]

SAE90 is a bit on the stiff side for cold temperatures. If you've never changed your differential lube, I'd maybe give some thought to drawing it all out, with a hand drawn suction tube (similar to a grease gun in appearance), aka: siphon gun and replacing it with a multi-viscosity, such as SAE 75-90. Do this just after driving, so the fluid is warm and flows better. Alternatively, you can add a drain plug to the axle housing.

Considering the service manual specified ATF as the transmission lubricant, substituting it with gear oil creates some concern. First would be cold weather usage both in terms of operation and thee added stress of moving what would be a near grease like consistency. I'd check ahead to the latest year that transmission was utilized and see what are specifying.

I wouldn't be afraid to utilize ATF. They still use ATF as a lubricant in a gear case. My 2015 Jeep Grand Cherokee specifies ATF for the transfer case.

When if first got it it looked like the original gear oil, closer to a solid than a liquid. I used one of those hand pump vacuum pumps they use for brake bleeds to get most of it out then filled it with some diesel and spun the wheels by hand to agitate the old sludge, after I flushed it I put 80-90w in it and never had issues, It is time I changed it to get any last sludge out of it and wanted to verify that using non-straight 90 is safe.

I had went through my transmission a little after I got it to replace the seals, I don't recall what came out of it but the internals were in near flawless condition so after new seals I put it back in with new shift bushings. At the time I had read of people using gear oil so that's what I put in it, I was shocked when I looked at the manual the other day and it called for ATF! I never had any issues with gear oil in terms of shifting performance but I know oils have a big role in a syncro performance, my 59 austin healy uses sae 30. I had put in synthetic and would grind every gear due to the friction modifiers present in synthetic oils, the only time it shifts perfectly is when I use bottom shelf conventional oil. This is why I am skeptical to use ATF but from what I see I guess its worth a shot, after all that's what the people who designed it recommend!

[64D100Poly]

I run synthetic oils in everything unless it is an engine with a rope seal for a rear main.

One wonders if one still needs the ZDDP with a synthetic for the cam and tappets, or even if it those additives are compatible with the synthetic. I think I may give a call to the folks at Amzoil, as they're pretty helpful with information like that.

I use Valvoline VR1 It's supposed to have high zinc content.

[PwrWgnDrvr]

This is why I am skeptical to use ATF but from what I see I guess its worth a shot, after all that's what the people who designed it recommend!

But the term "ATF" in 1964 means something totally different than ATF on the shelf today.

[nutz]

atf is around a 10 weight hydro fluid with a detergent in it
some syncros need a friction additives but i've only heard of early euro cars needing it
my 67 rear had the nastiest oil i've ever seen ,it came out in chunks ,if yours is anything like what mine was might want to drill a hole and add a drain plug

[64D100Poly]

atf is around a 10 weight hydro fluid with a detergent in it
some syncros need a friction additives but i've only heard of early euro cars needing it
my 67 rear had the nastiest oil i've ever seen ,it came out in chunks ,if yours is anything like what mine was might want to drill a hole and add a drain plug

I'm thinking that's what I'm going to do, I decided to stick with the gear oil in the trans, I started reading up on a number of people who opened up old 3 spd's that had ATF in em and the wear was significantly more then trans with gear oil of the same mileage.

[Hobcobble]

http://www.lesfrickshun.com/nostalgia-motor-oils.html
Good people to work with..... Support the small guys....
John

[64D100Poly]

http://www.lesfrickshun.com/nostalgia-motor-oils.html
Good people to work with..... Support the small guys....
John

Thanks for recommending them, looks like they got some good stuff!

[68swep]

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[68swep]

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