STP in transmission oil

[mrtexas]

I'd like to buy some 680 viscosity oil(thicker than 600w or SAE 140) for easy shifting but don't want to buy 5 gallons.

Anyone adding STP to transmission oil to thicken it?

Anyone willing to sell me 680 viscosity oil enough for two transmissions?

[Pete]

How about adding corn starch to some SAE 140?
It works with cake batter.
Or how about talking one of your ex co-workers out of some.

[d.]

Roger Kauffman, late MARC technical editor, said he used straight 100% STP in his transmission, steering box and rear end for 100,000 plus miles and stated that the fluid looked like the day he put it in, with no problems over many miles of cross country driving.
Reference his articles in the MARC NEWS.
It worked well for him with many road miles.

[Gil Sissons]

Steve Mitchell....(Mitchell Overdrive) advised me this week 25%

[duke36]

I purchased Lubriplate SPO 288 gear oil by the gallon many years ago. It's about 250 SAE,very thick. and the closest I found to the actual 600w. Bearing supplies companies may sell it or Google for a distributor. It's still listed on the Lubriplate web site as available.

[Ron in Quincy]

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I have used straight STP in my transmissions for years and have had no problems. The turning cluster gear continually picks up the STP and distributes it upward to all gears. Sure makes shifting easier.

I also use 50 percent STP in the differential. The ring gear continually pick up the STP and distributes it to the top of the differential keeping spider gears, pinion, etc. well lubed.

Ron

[Mike V. Florida]

Originally Posted by mrtexas

I'd like to buy some 680 viscosity oil(thicker than 600w or SAE 140) for easy shifting but don't want to buy 5 gallons.

Anyone adding STP to transmission oil to thicken it?

Anyone willing to sell me 680 viscosity oil enough for two transmissions?

A bunch of people have done it and many have just bought what the vendors sell.

I have never read of a problem caused by using STP.

[Mike V. Florida]

Mobil 600W super is rated ISO460 and the regular is something like 375. Why do you feel you need 680?

[Redbird]

Get the 600w from berts.

[mrtexas]

Originally Posted by Mike V. Florida

Mobil 600W super is rated ISO460 and the regular is something like 375. Why do you feel you need 680?

In the past I bought 5 gallons of 460 and 680. A local wholesaler sold most of the oil for me. The 680 made shifting very easy in the summer. It was too stiff in the winter however. What I have in there now requires the idle to be very low to avoid grinding 1st gear.

[Mitch//pa]

Originally Posted by mrtexas

In the past I bought 5 gallons of 460 and 680. A local wholesaler sold most of the oil for me. The 680 made shifting very easy in the summer. It was too stiff in the winter however. What I have in there now requires the idle to be very low to avoid grinding 1st gear.

what do you have in there now?

[jerry shook]

I add 8 0z of slick 50 along with 600w to all my manual transmissions and rear end it keep them cooler because of less friction. trans shift much smoother.

[Tim B.]

What about the clutch rod? Do you have it adjusted enough to accually push the throwout bearing far enough to release the disc? It may need adjustment. Just a thought. Tim

[johnmi]

What specific kind of STP are you guys using in your transmission Thanks John

[J Witt]

Racers used to call it Synthetic Total Performance. ;-)

http://www.stp.com/products/multipur...FVU6gQodK_YCtQ

John

[Dollar Bill]

"What specific kind of STP are you guys using in your transmission Thanks John"

Click here: STP

[Terry, NJ]

While I like STP for it's positive propertys, don't think of it as a magic bullet! It works fine in a Mod.A but not in some other transmissions. Maybe it's the ones with "Yellow metal" bearings, I don't know. However, I wrecked a Ford/Mazda 5 spd in my 88 E-150 with it. So it must be used sparingly. The Ford/Mazda box uses ATF (??) like some Chrysler standards did back in the seventies. I wouldn't advise putting it in a modern gearbox.
Terry

[BILL WILLIAMSON]

STP in a synchronized trans, is TOO SCHLICKERY & CAUSES THE SYNCHROS NOT TO BE ABLE TO DO THEIR THING.
Bill W.