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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I don't have a nickname, but I slept in a town with a holiday in express last night...
GM rear diff fluid with additive already in (part number listed above years ago) is synthetic and it seems everyone uses this that I have talked to or read.
The tremec is another story. People use all different stuff. My understanding is you want to make sure it's dexron III not VI. VI is probably too thin, I think... For track you want a syn that can handle high temp. I have used M1 ATF, and now only use Redline D4, as most trackers I've talked to use this, and it shifts maybe a bit better than stock and M1 cold, and when warm, it is very consistent. Only when my MT is hot does it really shift well, always been that way, regardless of fluid used. I read Hib wrote he uses Redline ultralight shockproof, not D4 (not to write for him)... Interesting choice. I would guess that is thicker than D4, but I'd have to look into it and will when I change fluids next. So I wonder if it shifts harder when cold.
I look at it as all good, speced fluids protect gears, but the diff will slip or catch if not using the right additive pack, and the tranny will either grind or shift slow if you use too thin or thick of fluid and you force a shift. And if you track a car, you want the car to work best when HOT, not shift well when cold or warm like you see on the road even when driven for hours.. I use D4 partly because it works well at all temps and partly because I think it can take the heat and tolerate a long change interval well.
I don't have a nickname, but I slept in a town with a holiday in express last night...
GM rear diff fluid with additive already in (part number listed above years ago) is synthetic and it seems everyone uses this that I have talked to or read.
The tremec is another story. People use all different stuff. My understanding is you want to make sure it's dexron III not VI. VI is probably too thin, I think... For track you want a syn that can handle high temp. I have used M1 ATF, and now only use Redline D4, as most trackers I've talked to use this, and it shifts maybe a bit better than stock and M1 cold, and when warm, it is very consistent. Only when my MT is hot does it really shift well, always been that way, regardless of fluid used. I read Hib wrote he uses Redline ultralight shockproof, not D4 (not to write for him)... Interesting choice. I would guess that is thicker than D4, but I'd have to look into it and will when I change fluids next. So I wonder if it shifts harder when cold.
I look at it as all good, speced fluids protect gears, but the diff will slip or catch if not using the right additive pack, and the tranny will either grind or shift slow if you use too thin or thick of fluid and you force a shift. And if you track a car, you want the car to work best when HOT, not shift well when cold or warm like you see on the road even when driven for hours.. I use D4 partly because it works well at all temps and partly because I think it can take the heat and tolerate a long change interval well.
Thanks for taking the time. What is the diff PN? I guess there are 3. Fluid no additive, additive, fluid with additive already in .
I don't have the clip problem anymore! I eliminated the diff cooler and lines. And I eliminated the trans cooler plumbing at the same time. Lots of those little clips eliminated. Reason was I'm not tracking the car anymore. For daily and drags I found neither the trans or diff gets excessively hot. Checked using an IR gun. But you have to connect a line on the trans output line to the input to let the fluid circulate. Hose works fine as it's not hi pressure. Buy the base Corvette plain diff cover
I don't have the clip problem anymore! I eliminated the diff cooler and lines. And I eliminated the trans cooler plumbing at the same time. Lots of those little clips eliminated. Reason was I'm not tracking the car anymore. For daily and drags I found neither the trans or diff gets excessively hot. Checked using an IR gun. But you have to connect a line on the trans output line to the input to let the fluid circulate. Hose works fine as it's not hi pressure. Buy the base Corvette plain diff cover
Where exactly are these coolers? Are there pumps moving the fluid? Fans?
Where exactly are these coolers? Are there pumps moving the fluid? Fans?
The diff cooler is attached to the diff. The pump comes out when you remove the diff cover. Replace the cover with the regular cover. The trans cooler line goes to the radiator. Then back to the diff cooler and out to the tranny. Didn't want to take the tranny out to remove it's pump so just looped it by putting a 1/8 pipe thread with hose barb fitting on the trans input connection with a hose to the short line coming out the front of the tranny. A whole lot of plumbing eliminated. For the oil cooler you need the block plug to replace the hose plug on the side of the block, And you need the bypass fitting that goes on the block when you remove the oil cooler. These are standard parts for a base Vette. Also a rubber plug for the radiator fitting. Oil temp finally gets up to operating temp now. Never got above 200 degrees for daily and drags. You do need all the coolers if tracking.
Last edited by 548chevelle; 04-06-2019 at 11:00 AM.
Reason: spell correction
The diff cooler is attached to the diff. The pump comes out when you remove the diff cover. Replace the cover with the regular cover. The trans cooler line goes to the radiator. Then back to the diff cooler and out to the tranny. Didn't want to take the tranny out to remove it's pump so just looped it by putting a 1/8 pipe thread with hose barb fitting on the trans input connection with a hose to the short line coming out the front of the tranny. A whole lot of plumbing eliminated. For the oil cooler you need the block plug to replace the hose plug on the side of the block, And you need the bypass fitting that goes on the block when you remove the oil cooler. These are standard parts for a base Vette. Also a rubber plug for the radiator fitting. Oil temp finally gets up to operating temp now. Never got above 200 degrees for daily and drags. You do need all the coolers if tracking.
I changed the fluid this weekend and now have a small leak from the drain / line to the diff cooler. I don't remember seeing an o-ring on the fitting, but didn't specifically look for it either. Is there an o-ring, and if so, does anyone have the part number?
I changed the fluid this weekend and now have a small leak from the drain / line to the diff cooler. I don't remember seeing an o-ring on the fitting, but didn't specifically look for it either. Is there an o-ring, and if so, does anyone have the part number?
What year is your car? How did you drain the fluid out without removing the clip and hose? The early cars required you to disconnect the diff cooler from the bottom of the diff. IIRC, the later cars have a drain.
Originally Posted by urslooow
Were there any o rings on the drain or fill plugs? I did trans and diff. Was super easy except for that stupid little clip on the diff drain
Wasn't there a hose connected to the line you disconnected?
What year is your car? How did you drain the fluid out without removing the clip and hose? The early cars required you to disconnect the diff cooler from the bottom of the diff. IIRC, the later cars have a drain.
Wasn't there a hose connected to the line you disconnected?
My 09Z has the clip and a hard line to the tranny cooler. You can only pull it out part way as it comes out horizontally and butts up against the composite spring before coming all the way out.
Enchanter,
I just went through changing my rear diff.lube and also had a leak afterward. Depending on your year, the rear diff. drain looks something like this -
There is indeed an o-ring inside the fitting. You can see it in this pic of a std. transmission cooler fitting GM part # 19210848
This is the actual fitting GM part number 10352222
And here's the clip GM part # 24205103
The o-ring is all that seals this fitting. I don't have the individual o-ring part #. The actual fitting is pricey - about $30. The o-ring from a std. GM trans.cooler fitting ( about $ 5 ) is identical in size. You'll need to look closely to make sure it's still in position. It can be changed without removing the fitting. Just use a dental pick type tool to remove, and maybe some hemostats and a small flat blade to re-insert the new one. Be sure to either use a new clip, or at least inspect the old one to ensure it looks like the pic. The DIY articles usually say there will be a distinct click as you re-insert the cooler tube. That's true if you install the clip first. If you install the clip after the cooler tube, your just pushing past an o-ring - no click. Lastly, the actual fitting comes with some type of lubricant inside the fitting. This aids the cooler tube going past the o-ring vs. pushing it inside the diff. I'm sure some will say just go to the hardware store and find an o-ring for 30 cents. That's fine, but at least make sure it's made from something that will resist oil ( Viton ? ). I'm guessing that's way more about the rear diff. drain than you wanted to know
Good luck -
Im about to do this on my wifes 09 Z and looking at the pics 2 posts above (since all the original pics are long gone and no one has replaced), thats a standard clip thats been used for millennia on transmission coolers and lines. It does need to be slid out of position to remove the line, but its intended to be back in that position before you re-insert so that you can hear the audible, "click" to confirm its properly installed. That being said, these type of clips always rely on a plastic retainer ring to be snapped down over them to lock them in place. I dont see in the pic above that this ring could be used?
Im about to do this on my wifes 09 Z and looking at the pics 2 posts above (since all the original pics are long gone and no one has replaced), thats a standard clip thats been used for millennia on transmission coolers and lines. It does need to be slid out of position to remove the line, but its intended to be back in that position before you re-insert so that you can hear the audible, "click" to confirm its properly installed. That being said, these type of clips always rely on a plastic retainer ring to be snapped down over them to lock them in place. I dont see in the pic above that this ring could be used?
My 07 did not have a plastic ring over the wire retainer.
04-05-2019, 12:32 AM
