Gear grind after cold start

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Nov 25, 2013 | 11:12 AM

magneticred99

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From: Detroit Michigan

Gear grind after cold start

My '99 was parked for about 2 weeks with temps in the low 20's here in Michigan. It started up just fine yesterday, but 3rd gear would grind before notching in. I didn't have a problem getting it into gear, but it would grind as it went it and it was exclusive to 3rd gear. This went away after about 20 minutes once the car was up to temp. I drove it about 3 hours later and it did not do this at all. Any thoughts?

Nov 25, 2013 | 01:08 PM

Bill Curlee

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From: Anthony TX

CI 6,7,8,9,11 Vet

St. Jude Donor '08

When was the last time you changed your MN6 ATF Transmission fluid???

Before you get too concerned, Change your MN6 Transmission ATF Fluid. The OEM fill is DEXTRON III.. YES,, your six speed fill is ATF!

You can use DEXTRON VI or AMSOIL Torque drive ATF as a replacement fluid.. IMHO, I would use the AMSOIL Torque Drive. You will need 4 quarts. You will only be able to drain and refill 3.75 qts.

See if that resolves your grind issue. It did for my 98 Coupe. You normaly see improved shift feel when you refresh your MN6/MN12 Trans ATF,

Bill

Nov 25, 2013 | 01:09 PM

Bill Curlee

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From: Anthony TX

CI 6,7,8,9,11 Vet

St. Jude Donor '08

Great like minds think alike!!!!!!!!!!

Nov 26, 2013 | 07:47 AM

magneticred99

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From: Detroit Michigan

Quote:

Originally Posted by 8VETTE7

Grind was likely because the trans lubricant was a bit thick until it got warmed up some.

When was the last time you changed the trans lube???

Thanks for the reply guys. I bought it with about 90k on the clock and have driven it about 3k since then. As far as I know, the trans fluid has not been changed. I was going to change it as a precaution when I first bought it, but a few people gave me negative feedback stating that it could do harm...which I never quite understood....but I'm going to put that aside and just swap the fluid.

Nov 26, 2013 | 11:13 AM

cv67

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From: altered state

St. Jude Donor '05

Quote:

but a few people gave me negative feedback stating that it could do harm..

Thats just

Sounds like someone who has never turned a wrench was giving advice that never happens on the internet

Nov 26, 2013 | 11:34 AM

magneticred99

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From: Detroit Michigan

Quote:

Originally Posted by cuisinartvette

Thats just

Sounds like someone who has never turned a wrench was giving advice that never happens on the internet

This is why I never pretend like I know what I'm talking about, because I usually don't. It's why I come here for the good advice.

Nov 29, 2013 | 12:04 PM

C66 Racing

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Joined: Aug 2001

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From: King George VA

Quote:

Originally Posted by Bill Curlee

You can use DEXTRON VI or AMSOIL Torque drive ATF as a replacement fluid.. IMHO, I would use the AMSOIL Torque Drive. You will need 4 quarts. You will only be able to drain and refill 3.75 qts.

Bill,
Dexron VI has a viscosity about 40% below that of the superseded Dexron III and GM doesn't use it in manual transmissions. Their fluid for manuals is now GM part 88861800.

For the OP, I do use the AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G) in my 02 Z06 at the track.

More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.

__________________

C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)

Nov 29, 2013 | 05:45 PM

leadfoot4

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From: Western NY

FWIW, I put up my C-5 for the winter last weekend, just before the snow hit town. I did, however, take it for an extended ride the day before, and it WAS cold. The shifting was a little "notchy" until the fluids warmed up.