Pontiac GTO Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
46 Posts
Discussion Starter #1
I believe I understand what is happening, but I am looking for opinions and suggestions.

I am the original owner of a 2006 GTO 6 speed manual, with just under 40,000 miles. The car is all original with the exception of a cold air intake and a diablo sport performance program. I do not race or abuse my GTO other than the occasional down shift into 3rd at 50mph to pass, or a high speed run up the on ramp to get on the interstate.

Here recently when I change gears the action between shifts feels like I am moving an oar through mud. The car shifts into gear without any grinding or attempts to jump out of gear, whether I am cruising at low rpm or shifting quickly at high torque, high rpm. If I am sitting still and just running through the gears with the engine off or idling I have no issues. I can push the shifter to the far right or left and it will spring back to the center on it's own.

I think I need to drain and replace the oem transmission fluid. I intend to do this over the next weekend to see if this solves my issue.

I would appreciate any thoughts on this subject.

Thank you

Michael.
 

·
Registered
Joined
·
34 Posts
Hey Mike,

Changing the fluid is the way to go. I used Mobil 1 synthetic ATF on mine at 18k miles and WOW! What a difference in the way it shifted. Butter smooth into the gears now. I always had a slight 'catch' when going first to second, but after changing the fluid it makes it seem new!

Be careful, the old stuff that comes out is NASTY. I believe it takes 4.6 Quarts. I filled it through the reverse light switch.

Nice looking GTO by the way.

-Brendan
 

·
Former Moderator
Joined
·
4,081 Posts
IMHO the best option to replace fluid is GM 88861800 DexIII available through Amazon as well as other places. I have used Royal Purple and Mobil 1. I know many have used both without issues. When I used RP it caused an odd condition that although it shifted smoothly most of the time it would occasionally cause the shifter to go completely limp like the shifter had become disconnected and grind the next gear. Putting it back to its starting position and reshifting would cause it to work again. I switched to M1 and it did the some thing occasionally. After doing a lot of reading I then switched to the GM recommended 88861800 and never had the problem again. It had something to do with the syncros and perhaps tolerances of other transmission didn't cause it to exhibit itself but syncros rely on some drag to work properly.

Although it wouldn't hurt to do a fluid change it might not be your problem. The stock shifter is an inferior unit as well.
 

·
Premium Member
Joined
·
4 Posts
You indicated the stock shifter is inferior with which I agree. What is a better unit? I am thinking of replacing mine with a Hurst 6-speed short throw shifter. Any ideas?
 

·
Registered
Joined
·
7 Posts
I agree with Svede about the 88861800 GM Manual Transmission and Transfer Case Fluid. GM released a dealership TechLink publication a while back that mentions the changes for power steering and manual trans fluid from Dex III. Look about 2/3 down the first page to the second "TIP": http://api.viglink.com/api/click?format=go&jsonp=vglnk_145784013044912&key=22d186f18b287d56e9b211009abcd0e2&libId=ilq0cnbt01000b1y000DLby5vb2e1&loc=http://www.ls1gto.com/forums/showthread.php?t=722498&v=1&out=http://www.sandyblogs.com/techlink/techlink_May_09.pdf&ref=https://www.google.com/&title=Fast Rack Install / Proper Fluid / Steering Column Knuckle Bolt - LS1GTO.com Forums&txt=http://www.sandyblogs.com/techlink/techlink_May_09.pdf

The hurst shifter is garbage. I have a GMM Ripshifter Race Version and love it, although a bit pricey. I've heard good things about the MGW-P and the Hinson shifter as well.
 

·
Registered
Joined
·
1,116 Posts
I agree with Svede about the 88861800 GM Manual Transmission and Transfer Case Fluid. GM released a dealership TechLink publication a while back that mentions the changes for power steering and manual trans fluid from Dex III. Look about 2/3 down the first page to the second "TIP": http://api.viglink.com/api/click?format=go&jsonp=vglnk_145784013044912&key=22d186f18b287d56e9b211009abcd0e2&libId=ilq0cnbt01000b1y000DLby5vb2e1&loc=http://www.ls1gto.com/forums/showthread.php?t=722498&v=1&out=http://www.sandyblogs.com/techlink/techlink_May_09.pdf&ref=https://www.google.com/&title=Fast Rack Install / Proper Fluid / Steering Column Knuckle Bolt - LS1GTO.com Forums&txt=http://www.sandyblogs.com/techlink/techlink_May_09.pdf

The hurst shifter is garbage. I have a GMM Ripshifter Race Version and love it, although a bit pricey. I've heard good things about the MGW-P and the Hinson shifter as well.
IMO if you are not going with Billett Pro then MGW-P is best option.
 

·
Former Moderator
Joined
·
4,081 Posts
MGW-P, McLeod, GMM or Billet Pro are all far superior to about every other thing out there. The Hurst is sadly not one of them.
 

·
Registered
Joined
·
361 Posts
I'm interested in the Hinson shifter when/if i ever get rid of my stock shifter
 
1 - 9 of 9 Posts
Top