[TJay74]

Originally Posted by Bow Tie Affair

Does anybody have torque values for the cross member and transmission mount?

To be honest, the OEM torque values were petty low. It didn't take much to break the 15mm bolts free. I just ran them down and snugged them down to where I know they wont back out.

[MatthewAMEL]

Nice write up.

I'm not a fan of Royal Purple. Will a standard 75-90 synthetic work? Motul/Mobil1?

[Bow Tie Affair]

Originally Posted by TJay74

To be honest, the OEM torque values were petty low. It didn't take much to break the 15mm bolts free. I just ran them down and snugged them down to where I know they wont back out.

[TJay74]

Originally Posted by MatthewAMEL

Nice write up.

I'm not a fan of Royal Purple. Will a standard 75-90 synthetic work? Motul/Mobil1?

Well the GM fluid is a synthetic already. I can say usually I am a Mobile fan as well, but lately I have swapped our oils over to Castrol and this time went with RP MAX ATF for the 1LE transmission. It is a lot better than the GM OEM fluid, but there are still issue in the transmission that the dealer will be looking at in 2 weeks for me.

[DFW1LE]

I saw the why and how, which was great, but what about the results after the change. Did it smooth out and meet your expectations?

[cwebster]

Originally Posted by DFW1LE

I saw the why and how, which was great, but what about the results after the change. Did it smooth out and meet your expectations?

Yes, it did meet my expectations - not a huge difference but noticeable, especially once it warmed up. Before the change I could feel the gears mesh and sometimes even hear them. After the change shifts are much more smooth. Maybe unscientific but speed-shifts at the drag strip seem to take less effort and go more smoothly. See helmet GoPro footage below. Sorry, don't have any helmet cam before...

Staged at the tree about 1:53

[cwebster]

Originally Posted by TJay74

Well the GM fluid is a synthetic already. I can say usually I am a Mobile fan as well, but lately I have swapped our oils over to Castrol and this time went with RP MAX ATF for the 1LE transmission. It is a lot better than the GM OEM fluid, but there are still issue in the transmission that the dealer will be looking at in 2 weeks for me.

I know some have used the RP Max ATF for earlier model Camaro manual transmissions but that's not what GM or RP recommends for the ZL1. The Tremec TR-6060 data sheet does call for Dextron III ATF so it should be okay if you do use it. However, I'd prefer to stay closer to lubricants upon which GM based their testing and tuning. While conducting my research I downloaded this (PDF) cross-reference chart from the Royal Purple web site:

http://www.royalpurpleconsumer.com/a..._Reference.pdf

If you search the chart for recommended fluid to replace OEM fluid by GM PN 88861800 (from owner's manual), you see that they recommend Synchromax. It is specifically formulated for manual transmissions.

On the description page for Synchromax:

Synchromax is recommended for manual transmissions that specify an automatic transmission fluid.

--Cal

[DFW1LE]

Originally Posted by cwebster

Yes, it did meet my expectations - not a huge difference but noticeable, especially once it warmed up. Before the change I could feel the gears mesh and sometimes even hear them. After the change shifts are much more smooth. Maybe unscientific but speed-shifts at the drag strip seem to take less effort and go more smoothly. See helmet GoPro footage below. Sorry, don't have any helmet cam before...

Staged at the tree about 1:53

Thanks, glad to hear it, that run looked smooth to me!

[TJay74]

Originally Posted by cwebster

I know some have used the RP Max ATF for earlier model Camaro manual transmissions but that's not what GM or RP recommends for the ZL1. The Tremec TR-6060 data sheet does call for Dextron III ATF so it should be okay if you do use it. However, I'd prefer to stay closer to lubricants upon which GM based their testing and tuning. While conducting my research I downloaded this (PDF) cross-reference chart from the Royal Purple web site:

http://www.royalpurpleconsumer.com/a..._Reference.pdf

If you search the chart for recommended fluid to replace OEM fluid by GM PN 88861800 (from owner's manual), you see that they recommend Synchromax. It is specifically formulated for manual transmissions.

On the description page for Synchromax:
--Cal

I will have to go find some of that then. As you said, while the RP MAT ATF may not be what GM wants you to use, the immense improvement it made in shifting was a night and day difference in shifting.

When I first got my 1LE and left for work on a 35° morning it was 6 miles before I could get the shifts to go without it sounding like a bag of marbles where in the transmission. The 1st to 2nd shift was so brutal and rough that I was surprised GM QC was ok with this kind of shifting effort.

Neither my 2001 Formula Firebird with the M6 nor my 2008 Corvette with the M6 shifted like this, both were smooth as butter.

[cwebster]

Originally Posted by TJay74

I will have to go find some of that then. As you said, while the RP MAT ATF may not be what GM wants you to use, the immense improvement it made in shifting was a night and day difference in shifting.

When I first got my 1LE and left for work on a 35° morning it was 6 miles before I could get the shifts to go without it sounding like a bag of marbles where in the transmission. The 1st to 2nd shift was so brutal and rough that I was surprised GM QC was ok with this kind of shifting effort.

Neither my 2001 Formula Firebird with the M6 nor my 2008 Corvette with the M6 shifted like this, both were smooth as butter.

Wow! That sounds horrible! I had basically the same complaints in my 5th Gen 1LE. In cold climates machines need lower viscosity fluids if you're going to drive them before they warm up. Suppliers often achieve this using "friction and viscosity modifiers" and "film strength" additives. My recommendation, regardless of the fluid you use, is to let the car warm up a bit more before driving when it's cold.

Since both the 6th Gen SS 1LE and ZL1 use the same M6 (not sure about the non-1LE SS), you'll probably be okay with the Max ATF if you've already swapped it in, since Tremec calls for ATF. If not, I'd go with the Synchromax.

Main reasons I chose Synchromax over Max ATF was (1) Synchromax was recommended for the GM fluid replacement in their cross-reference chart, and (2) disclaimers listed in the Max ATF spec sheet cited GM Dextron VI, the ATF that GM uses in their auto-trans. I figured that if GM will deny warranty claims for Max ATF in their auto transmissions, they're not likely to honor a claim using it in their manual ones either.

Cross-reference chart (PDF)

Synchromax Data Sheet (PDF)

Synchromax is recommended for manual transmissions that specify an automatic transmission fluid.
...
Synchromax is formulated with Royal Purple’s synthetic,
proprietary Synerlec additive technology, offering
improved shift quality over a wide temperature range and
reduced gear noise.
...
Viscosity Index 175

Max ATF Data Sheet (PDF)

Please note: Max ATF is not recommended or an approved warranty replace-
ment for: For dType F, Ford Mercon SP,Ford Mercon LV, GM Dexron VI,
Mercedes Benz NA G-2, Toyota WS, Volvo 5 Speeed.
...
Viscosity Index: 210

You'll note that, although both have exceptionally high viscosity index, the Max ATF is higher; meaning that in general it will provide favorable viscosity over a wider range of temperatures. However, the manual transmissions must cope with both reducing friction to minimize wear on gears while at the same time providing enough friction for synchronizers (synchros) to lock-up so your shifts don't sound "like a bag of marbles" or worse, wear down your gears. This is why high quality manual transmission fluids have both viscosity and friction modifiers or additives. I'm not a chemist so I can't tell you exactly how each works but you need both in the M6.

Do some Googling to learn more about manual vs auto transmissions and lubricants. That's what I did while researching this change. You will learn a lot more if you do the research yourself too.

Let us know how your choice turns out. Good luck!

--Cal

[TJay74]

Will do man, I may end up changing it out this week on my days off just to try it. Not like it a costly change out, plus maybe it will flush some more junk out.

[Ankh599]

Thanks for the info. All this time I thought it was the boost. My biggest issue with my ZL1 is coming out of first gear doing the Launch Control. Do you have the same issue?

[cwebster]

Originally Posted by Ankh599

Thanks for the info. All this time I thought it was the boost. My biggest issue with my ZL1 is coming out of first gear doing the Launch Control. Do you have the same issue?

No, I've never had it pop out of 1st gear... knock-on-wood. If you have shifting issues described here you may benefit by switching over to RP Synchromax, though.

--Cal

[DFW1LE]

Originally Posted by cwebster

Since both the 6th Gen SS 1LE and ZL1 use the same M6 (not sure about the non-1LE SS), you'll probably be okay with the Max ATF if you've already swapped it in, since Tremec calls for ATF. If not, I'd go with the Synchromax.

I believe the ZL1 and 1LE have different transmissions and clutch assemblies.