I have a 1980 Malibu with the factory Saginaw 4 speed in it. I don't know when the last time the transmission was serviced (if ever). Its a bit fussy on the 3-2 downshift, and I'm wondering if I should just drain it and put fresh oil in it, or if there is as additive out there for manual transmissions that will allow them to shift more smoothly. A friend recommended that I put some of the GM posi rear end additive in it. Any thoughts or ideas? Thanks.
Manual transmission fluid or additive?
- Thread starter clean8485
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Jeff,
I know there's an additive that's used in Porsche transaxles. I'll have to look it up and let you know.
Here's a link to the product(s). The stuff isn't cheap, though. I read on a Porsche forum, GM posi additive was also mentioned. It might be worth trying.https://www.paragon-products.com/Swepco-212-Gear-Oil-with-MoS2-p/swepco-212.htm
I know there's an additive that's used in Porsche transaxles. I'll have to look it up and let you know.
Here's a link to the product(s). The stuff isn't cheap, though. I read on a Porsche forum, GM posi additive was also mentioned. It might be worth trying.https://www.paragon-products.com/Swepco-212-Gear-Oil-with-MoS2-p/swepco-212.htm
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are you talking about this product?
https://www.paragon-products.com/Swepco-201-Transmission-Fluid-p/swepco-201.htm
It should just take conventional 80W90 gear oil. I would stay away from synthetic as I have read some yellow metals are not compatible. Not sure on that. Just what I've read....
https://www.jalopyjournal.com/forum/threads/saginaw-4-speed-lube.958785/
I think I'd try an oil change before putting limited slip additive in it. You wouldn't be gambling much.
Jared,
A fresh oil change might very well make a difference.
You certainly did, Steve.
After I saw your reply to the message, I noticed that I didn't include the link...my bad.
Be careful of friction modifiers. I just went through this with my Muncie. Modern transmissions have extra friction plates in the synchro (as I've been told), and benefit from modifiers. Old school designs do not. I tried Brad-Penn 80w-90 GL4 as recommended by AutoGear. It didn't work with my TrueTrac differential, and was less than impressive in the M22. I ended up with Redline Heavy Shockproof 85w-140 in both, and it works well.
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