With pushing a little harder, my converter is getting too loose for the application. Before sending in, the converter company suggested switching from the Dexron that I currently use to a hydraulic fluid at least 30 weight. In order to see how much that tightens it.

First question: Is this hydraulic fluid or what the tractor companies often call hydrostatic fluid.....or are they the same thing?

Second question: What weights are available and appropriate? If I could tighten at least 300 rpm that would be ideal.

Third question: How is best to get a complete swap? Drain, fill, run, and repeat? How much would you buy quantity wise for this exercise?

Personally i dont like hydraulic fluid because it doesnt have shift modifiers in it that is needed for the clutches. Does hydraulic oil work and not burn up clutches? Of course, but it is not best. I would recommend the ati type F, they have a 20 and a 30 weight fluid that will tighten the converter.

I can't answer the questions on fluid, but here is the best way to do a fluid changeover, IMHO: Drop the pan, (and replace the filter while you're in there), fill the pan with about 3-4 quarts of the new fluid, then determine which cooler line is your return (to trans), disconnect that line, add a few feet of rubber fuel line to the end of it, place that in a large drain pan or bucket, start it up and let it pump out about 2 quarts. (Note: This will only take a few seconds, like 10 or so). Add 2 more quarts to fill tube, and repeat the procedure twice, (3 cycles of fill & pump should purge it completely). Remember, the converter holds most of your fluid. And because it generates the heat, the fluid flow is designed so the pump pushes the hot fluid from the converter out to the cooler, then the cooled fluid is returned to the pan. So using this method will purge the old fluid out of the converter and the cooler lines.
If your new fluid is a different color, that is even better, you will actually see the color change as it is pumping into the drain pan. Best is to have a helper start the car, while you watch the fluid flow into the pan. Signal them to shut it off after you have estimated 2 quarts have been pumped out, so you can add more to the pan. Then set your fluid level a bit on the low side, until you can warm it up and do a hot check. If you just drain the pan and fill with the new fluid, even 2 or 3 times, you will never get all the old fluid out, it will just mix with the new fluid.

quote:

Originally posted by Bucky:
With pushing a little harder, my converter is getting too loose for the application. Before sending in, the converter company suggested switching from the Dexron that I currently use to a hydraulic fluid at least 30 weight. In order to see how much that tightens it.

First question: Is this hydraulic fluid or what the tractor companies often call hydrostatic fluid.....or are they the same thing?

Second question: What weights are available and appropriate? If I could tighten at least 300 rpm that would be ideal.

Third question: How is best to get a complete swap? Drain, fill, run, and repeat? How much would you buy quantity wise for this exercise?

I tried John Deere hygard a couple years back. It tightened it up barely 100 RPM at the flash, and didn’t change the finish line slip percentage which is what I was trying to tighten up. All combos are different but I doubt you’re going to get the 300 you’re looking for with a fluid change.

We used to run Caterpillar HYDO in all our transmissions for many many years and it will give you about a 200 RPM tighter convertor and typically lock it up quicker.

quote:

Originally posted by 183N:

quote:

Originally posted by Bucky:
With pushing a little harder, my converter is getting too loose for the application. Before sending in, the converter company suggested switching from the Dexron that I currently use to a hydraulic fluid at least 30 weight. In order to see how much that tightens it.

First question: Is this hydraulic fluid or what the tractor companies often call hydrostatic fluid.....or are they the same thing?

Second question: What weights are available and appropriate? If I could tighten at least 300 rpm that would be ideal.

Third question: How is best to get a complete swap? Drain, fill, run, and repeat? How much would you buy quantity wise for this exercise?

I tried John Deere hygard a couple years back. It tightened it up barely 100 RPM at the flash, and didn’t change the finish line slip percentage which is what I was trying to tighten up. All combos are different but I doubt you’re going to get the 300 you’re looking for with a fluid change.

I believe that Hy Guard is 10W (ISO32)from memory since I have purchased plenty of it for tractors. The suggestion was to go 30W (ISO68). I do track/monitor my trans fluid temp. I have read too that you want at least a quart of ATF in there so you can actually see it on the stick since the hydraulic fluid is clear.

I second FootBrakeJim's suggested displacement procedure. I've done the same procedure on my daily's. Might also suggest you drill some holes in you dipstick to aid in seeing the level.

It isn't bad for tuning a converter, we've used it. The problem is you gotta run the transmission stoned cold for it to do something, getting it there after a few licks is the problem. Once we knew what the converter wanted, it got sent in for a stall adjustment.

Transynd is faster

ATI Makes a 30W trans fluid you could try.

I think it is a good idea to try the heavier fluid and see if it tightens up your converter and helps your ET. Then if it works send the converter in to be tightened up and you will know what to expect.

I would not worry about getting 100% of the old fluid out of converter you just need enough to know verify that less stall will help your ET.

I do think it would be best to trade it out at the track after a pass so you can verify it is the fluid and not weather change, track or any other variables.

quote:

Originally posted by Curly1:
I think it is a good idea to try the heavier fluid and see if it tightens up your converter and helps your ET. Then if it works send the converter in to be tightened up and you will know what to expect.

I would not worry about getting 100% of the old fluid out of converter you just need enough to know verify that less stall will help your ET.

I do think it would be best to trade it out at the track after a pass so you can verify it is the fluid and not weather change, track or any other variables.

That's kind of the approach I'm trying. If it has the desired affect, I send in the converter and get what is left to get tightening this one up, which isn't a lot.

I will check out the ATI fluid

I think you are on the right track and it will answer questions.

Much easier and cheaper than pulling converters and shipping them back and forth and putting it back in.

I’m using VP hydraulic fluid in my stuff. Tractor supply has it. Super cheap. I used the tractor supply store brand before that. I saw around 150 rpm change on my nitrous converter when I switched from type f about 10 years ago. I would expect closer to 200 going from dex iii to hydraulic tractor fluid. I would think a bottle of Lucas would tighten it a few more but I’ve never actually ran that in a race car.

You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

Thank you all!

quote:

Originally posted by Stephen Hughes:
You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

What weight do you switch to? The 68? And how do you like the overall performance of the hydraulic fluid? Any different?

quote:

Originally posted by Bucky:

quote:

Originally posted by Stephen Hughes:
You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

What weight do you switch to? The 68? And how do you like the overall performance of the hydraulic fluid? Any different?

I used the Super S Super Trac 303 tractor hydraulic. Not exactly sure what weight it is. I had no issues with it performance wise. I ended up switching to redline lightweight atf trying to loosen my converter a tad in the hot summer months, but I have run it in every car I have over the years. I think it actually mph a tad better with the hydraulic, I’m assuming it helped make the converter a bit more efficient. After running in really good air at the end of last year and beginning of this year, I’ll probably switch back to it in the cooler months. The thin fluid was a little too loose in mineshaft air.

quote:

Originally posted by Stephen Hughes:

quote:

Originally posted by Bucky:

quote:

Originally posted by Stephen Hughes:
You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

What weight do you switch to? The 68? And how do you like the overall performance of the hydraulic fluid? Any different?

I used the Super S Super Trac 303 tractor hydraulic. Not exactly sure what weight it is. I had no issues with it performance wise. I ended up switching to redline lightweight atf trying to loosen my converter a tad in the hot summer months, but I have run it in every car I have over the years. I think it actually mph a tad better with the hydraulic, I’m assuming it helped make the converter a bit more efficient. After running in really good air at the end of last year and beginning of this year, I’ll probably switch back to it in the cooler months. The thin fluid was a little too loose in mineshaft air.

It's more likely that with the heavy oil, the stall is more suited the torque curve. Being the converter efficiency is according centrifugal force, if you're going faster mph at the stripe, the the rpm is higher making the converter more efficient due to additional centrifugal force (rpm), and not the heavier oil.

The bottom graph is transmission oil that is aired up. Same converter, same transmission oil.

Anyone care to take a quess how much faster the tapered pan was?

This message has been edited. Last edited by: Mike Rietow,

quote:

Originally posted by Stephen Hughes:

quote:

Originally posted by Bucky:

quote:

Originally posted by Stephen Hughes:
You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

What weight do you switch to? The 68? And how do you like the overall performance of the hydraulic fluid? Any different?

I used the Super S Super Trac 303 tractor hydraulic. Not exactly sure what weight it is. I had no issues with it performance wise. I ended up switching to redline lightweight atf trying to loosen my converter a tad in the hot summer months, but I have run it in every car I have over the years. I think it actually mph a tad better with the hydraulic, I’m assuming it helped make the converter a bit more efficient. After running in really good air at the end of last year and beginning of this year, I’ll probably switch back to it in the cooler months. The thin fluid was a little too loose in mineshaft air.

Spec sheet lists that one as an SAE20

quote:

Originally posted by Bucky:

quote:

Originally posted by Stephen Hughes:

quote:

Originally posted by Bucky:

quote:

Originally posted by Stephen Hughes:
You wont get 300 as mentioned above, but you’ll get 100-150 in the direction you want to go. When i switch it back and forth, i drain the pan, fill with the tractor hydraulic, fire it up , then drain one more time. It wastes some but I felt it got more of the regular fluid out of it that way.

What weight do you switch to? The 68? And how do you like the overall performance of the hydraulic fluid? Any different?

I used the Super S Super Trac 303 tractor hydraulic. Not exactly sure what weight it is. I had no issues with it performance wise. I ended up switching to redline lightweight atf trying to loosen my converter a tad in the hot summer months, but I have run it in every car I have over the years. I think it actually mph a tad better with the hydraulic, I’m assuming it helped make the converter a bit more efficient. After running in really good air at the end of last year and beginning of this year, I’ll probably switch back to it in the cooler months. The thin fluid was a little too loose in mineshaft air.

Spec sheet lists that one as an SAE20

If thats the case, maybe the 30wt trans fluid mentioned above would get you even closer to where you want to go.