I recently changed my M6 transmission fluid and noticed it had a burnt smell. Why would this happen ?. C5 with 50k

Also, what recommendations do you have on replacement fluid. I hear Redline makes a good product





[Modified by newride, 5:22 PM 10/26/2002]

 

I'm surprised, automatic transmission fluid shouldn't get much of a workout in a manual transmission.

I put in Mobil 1 Synthetic automatic trans fluid in mind. It does NOT come from factory with synthetic. It helps shifting in cold temperatures, some say it helps shifting allthe time.

The differential comes from the factory with sythetic. Plus if you change you must use friction modifier, if it is not in your replacement oil.

 

Gear oil has a different smell to it than motor oil. Open a bottle of fresh gear oil and compare. :reddevil

vetterdstr :cheers:

 

Yes, I changed to synthetic on my old '97 at 45K. The factory fluid smelled so burned it made me feel literally nauseous.

The synthetic fluid made a GIGANTIC difference in shifting. I was very pleasantly surprised.

:cheers:





[Modified by brewtoo, 6:43 PM 10/26/2002]

 

Hey Brewtoo, what kind did you use ?

 

Mobil 1. It was my third choice but it was available locally.

I had a lot of trouble with 1st and 2nd....hard to get in gear, popping out of gear. It was getting to where I dreaded driving the car.

It was DRAMATICALLY improved by the Mobil 1.

:cheers:

 

My MN6 is just like you described, hard to get all the way into first and second and if I am not carefull it will pop out. Did you do it yourself or have it done ? I do not have access to a lift to do this myself, but I am not sure it is a job for Jiffy-Lube either.

 

http://www.picturetrail.com/gmblack3/647207

 

Did it myself with Rhino Ramps. You can buy the Rhino Ramps and fluid pump for less than you would pay Jiffy-Lube to do the job....

:cheers:

 

What would happen if you forgot the friction modifer with Redline Fluids :D I think I may have missed that part :rolleyes: :eek:

 

Isn't that a concern for the differential? I said I put Mobil 1 in the transmission.

Did I miss something?

:cheers:

 

RedLine has the friction modifier in the differential fluid already.

-Rob

 

Redline 75W-90 has the friction modifier in it as stated above. Redline 75W-90NS does not have the modified in it. Check the bottles that you used. If you used the 75W-90, don't add more or you only defeat your limited slip capability. I have been told by a Redline rep. that the GM friction modifier is NOT compatible with Redline oils due to the difference in base oils.

Amsoil Series 2000 also has the friction modifier in the oil.

 

You may have answered why some people have problems changing the differential fluid to synthetic. Some people have clutch problems even with the modifier. It may be due to incompatibility.

They have to go back to regular oil with modifier to "fix" chatter.

I never knew or heard that GM's friction modifier is not compatible with Redline fluids. Although I personally would never use Redline because of warrenty issue (not approved).

 

I put the Amsoil Series 2000 75W-90 in my C5 with absolutely no problems or chatter. I used the Redline 75W-90 in my C4 without problems also. However, I have heard from some of the C4 guys that they were spinning only one tire at the track wtih Redline and had to reduce the modifier concentration to correct it. You can do this by removing some 75W-90 and putting in some 75W-90NP or starting with the 75W-90NP and mixing in your own modified concentration.

 

This is the info about the GM additive for the diff that I found on the net and by emailing redline:


Amsoil and Redline claim that there fluids already have an additive in them. Amsoil says it both ways on there 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.

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.

It states in the GM manual that no WOT for 300 miles after the diff fluid is changed.

I added the GM additive to the Amsoil series 2000 diff fluid and have had no problems.

 

Why would you do that, it defeats the capability of limited slip?

 

The M6 in the C5 runs VERY hot because of the lack of airflow and close proximity to two exhaust pipes. Thats why there are TF fluid cooling kits availible for the C5. Synthetic ATF is a must in this tranny because of the high temperatures.

 

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.

One word=Warranty.