stngh8r

well, like the topic says, i was just wondering if there are any contraindications to changing the M6 trans and rear end oil w/ 65k miles on it. I'm not sure if it has ever been changed before? i bought the car with bout 50k. I was also wanting to put some new clutch fluid in, the shifting is starting to get a little sticky and i hope this will help, as well as be good maintanence.

Thanks for the advice, you guys are great!

Dope

Definitely change it, you can't hurt anything. Well, unless you forget to refill it. 2 quarts of redline (choose your weight) and some GM limited slip additive and you're good to go.

Dope

Richin Chicago

I'd b a little careful about adding any limited additive as the Redline fluid already has about 4% friction modifiers added to their 75w/90. Too much and you will just have an open differential.
Redline's description "75W90 GEAR OIL
Recommended for most street driven and racing differentials. Excellent performance in conventional and limited-slip units. Also for limited-slip manual transaxles which require a 90 WT oil. Contains limited-slip friction modifiers.


Also the transmission takes just under 4 quarts of D4 ATF Redline.

Definitely worth the effort if you don't know the car's history.

Bandit1

Definately change it! Try AMSOIL. I think you'll like it. :thumbs:

Sabby

Yes, you should change it. And add a slip lock additive to the rear. Give Amsoil a try.

gmblack3

http://www.woosch.com/tranny_diff_fluid_change.htm

carpe dm

Do it! Good fluids = good car = :D

stngh8r

Thanks for all the replies. Guess i will get on the job right now. What about the clutch fluid, havent seen any comments on that yet? Will it improve the shift quality, which is poor and sticky right now.?

Again, thanks for the info and link.

Dope

I would add it, Redline doesn't have the same affect as GM additive. On BOTH of my Camaro SSes, and my 99 FRC, I have had groaning (chattering in the case of the Camaros, which have Auburn diffs), with just redline fluid. I always add the additive and have no trouble now. I just put in a DTE 3.90 rear and it says explicitly in the instructions to use GM additive and they even include a bottle of it (along with redline 75w90).

People who claim that you don't need the additive have obviously never done a fluid swap and had to live with the car later. Try using just redline fluid and then do some tight parking lot manuevers.

Dope

Richin Chicago

I have a 2000 hardtop with 35000 miles which I switched to Redline at less than 1000 miles. It is fine and will make any parking lot manuever you want. Also had a Camaro SS with almost 50,000 miles on it with the same story.
Redline already has 4% friction modifier in and I sure wouldn't add anymore until I heard noise. As stated before too much friction modifier and you defeat the limited slip. If you want I'll E_mail Redline and ask their opinion, but I'll bet there is a whole lot of people that have put Redline in with no extra additives and not had a problem.
This might make a good survey!

bnpb

I would give Redline a try. I know a guy who works in the industry and is a tribologist. Redline makes the most cutting edge lubricants on the market. They are very professional. Amsoil products are generally good, but they have some that are very over rated, such as there S2k oil. I'd go with RL and see how it works. Amsoil is the only company not using MoTDc, the molybdenum that is soluable. Every lubricant maker in the industry useses it and now Honda specifically calls for it. It's a great EP additive. RL motor oil uses it as well. No Hype with there products, just pure performance. Good luck. I questioned Amsoil about Moly and there response was mind-blowing. They said they don't use solids in lubricants. They must be a bit behind the times as the soluable Moly has been in oils for over 5yrs now and has gained tremendous poplularity. It's not the panacea, but it helps. Note, I'm not sure if RL diff. oil uses this....might want to check with them.


[Modified by bnpb, 11:22 PM 10/9/2003]

Dope

Thought I might also add, I'm 90% sure GM specifies the additive usage regardless of the fluid you use.

Dope

IMQUIK

:nono: :nono: :nono: I think you will love it! :yesnod:



[Modified by IMQUIK, 11:33 PM 10/9/2003]

AFVETTE

I'm going with AMSOIL. No additive required. After seeing a diff/tranny fluid change I know how easy it is.

Tom

gmblack3

I have done my diff w/ amsoil once with and once without the additive. No problems either time.

From the link above here is the info I gathered from redline:

Redline says:

LIMITED-SLIP COMPATIBILITY Red Line Gear Oils, with the exception of the 75W90NS, already contain friction modifier required for operation in limited-slip differentials. Additional additive is not required.

I have emailed Redline and asked them if it would not hurt to add the GM additive to Redline.

Here is the reply from redline

The 75W90 would be suitable for the limited slip in your Z06 it contains 5% friction modifier, typically what is needed to reduce the chatter from the limited slip when making a slow tight turn. Adding more friction modifier if it isn't needed reduces the lock up of the limited slip and reduces it's effectiveness, so I wouldn't add it unless it is needed due to chatter and then only just what is needed. The friction modifier isn't a lubricant but just an additive to make the fluid slipperier for chatter control. The 75W90 should be suitable right out of the bottle without the need for the additive. Thank you for your interest in Red Line Oil.

Amsoil says it both ways on their website:

AMSOIL gear oils are formulated with friction modifiers for limited slip differential applications. There is no need to add limited slip or additional additives.

AMSOIL Series 2000 Synthetic Gear Lube provides limited slip performance. Although generally not necessary, original equipment manufacturers' limited slip additives may be used in conjunction with AMSOIL Series 2000 Synthetic Gear Lube.





[Modified by gmblack3, 12:25 PM 10/10/2003]

TheBigGuy

Unless you plan to do racing, save your $ and use MOBIL 1 products in both the tranny and rear end. AND ad the G.M. rear end additive. This is factory fill stuff. That's my 2 CTS. :cheers: :chevy :flag

Richin Chicago

Funny you mention that. I changed both to Redline right after my first time on a roadcourse. I couldn't believe the heat buildup around the transmission.

Argo-7

I changed mine at 1002 on my 2004 Z06 shifting is better but just had it flat beded to dealer was locked in reverse gear. Took it off the flat bed and it was working ok. Hope I am close to home when it happens again :cheers: I did the magnitic kit from the C5 purchase/group /mall

C6~Missle

I have Redline in the rear diff. I did NOT add the GM modifier fluid. I don't have any chatter. Redline says its not necessary to add any modifiers.
mike

stngh8r

thanks for the many replies. I have the fluids now, just waiting for time to do it all. Did someone mention that it is pretty easy? Or is this something i should let a professional do?