• Want to add an app icon for this forum to your mobile device's home screen? Check out this thread to see how.
  • Have an event you want to share? Check out the new forum event calendar and how-to use it in this thread here.
  • To both new members and existing members, please read this thread about posting your topics in the correct sub-forum. It makes my job (and my life) a lot easier!

AX-5 rough in first gear

Jackman

TJ Enthusiast
Joined
Aug 5, 2018
Messages
166
Location
Mt morris,mi
98 4cyl 5 speed
When it’s cold ou the Jeep takes off out of first, acts like I’m trying to take off in second or third. Once I’ve gone down the road a bit it’s fine. Just when I first take off.
Would the redline Mt-90 possibly help with this?
 

TrueTexas

Member
Joined
Feb 7, 2019
Messages
70
Location
The Woodlands, TX
Changing the fluid would be a good start. Cheap and super easy to do.

MT-90 is high dollar. Keep in mind that Jeep has approved 10w-30 motor oil as a replacement tranny fluid.

That being said, both of my TJs have AX-15 tranny's, you have a 4 cyl so I'm assuming you have an AX-5. I have a gallon of MT-90 but used Pennzoil Syncromesh as a cheaper gl3 alternative until I got my tranny issues sorted out. However, it's been so smooth, I haven't changed it for the MT-90 yet. You may want to try motor oil or Pennzoil Syncromesh first to see if it improves your cold shift issue.
 

Flivver250

TJ Addict
Supporting Member
Joined
Jun 3, 2018
Messages
1,252
Location
Dubai/Florida
Maybe I am wrong, but taking off in first gear and shifting into first gear are two different actions. Cold or warm, once you are in gear, it should behave exactly the same. Shifting when warmed up becomes easier. If you are gutless when cold, that is a different scenario. Check your tune and codes. Red Line is a superior lubricant. Worth using.
 
  • Like
Reactions: Steel City 06

Steel City 06

TJ Addict
Joined
Mar 12, 2019
Messages
1,523
Location
Pittsburgh, PA
Maybe I am wrong, but taking off in first gear and shifting into first gear are two different actions. Cold or warm, once you are in gear, it should behave exactly the same. Shifting when warmed up becomes easier. If you are gutless when cold, that is a different scenario. Check your tune and codes. Red Line is a superior lubricant. Worth using.
X2. This doesn't sound like a transmission issue. Most likely related to the engine, or possibly the clutch, but likely not the transmission.

Has it not done this before? It could just be normal to a cold engine. Depending on how cold it is, it may be worth giving it 60 seconds to warm up before starting to drive. Use of a block heater would significantly reduce the time to heat up.

What RPM do you normally hold when letting out the clutch?
 
OP
Jackman

Jackman

TJ Enthusiast
Joined
Aug 5, 2018
Messages
166
Location
Mt morris,mi
X2. This doesn't sound like a transmission issue. Most likely related to the engine, or possibly the clutch, but likely not the transmission.

Has it not done this before? It could just be normal to a cold engine. Depending on how cold it is, it may be worth giving it 60 seconds to warm up before starting to drive. Use of a block heater would significantly reduce the time to heat up.

What RPM do you normally hold when letting out the clutch?
looks like I may have figured it out... the Jeep likes more throttle when letting off the clutch when cold.
 
  • Like
Reactions: Steel City 06

Flivver250

TJ Addict
Supporting Member
Joined
Jun 3, 2018
Messages
1,252
Location
Dubai/Florida
It is best for moving parts and the fuel system to be used at the proper operating temperature. Warm that pig up! Fuel, combustion chamber, metals and lubricants behave differently when cold. Give it some foreplay. My Vermont rule of thumb was to drive after the front windshield defroster was blowing warm. My record cold seen on the mercury there was -59 at Wallace pond in Canaan. Ice fishing for brownies. My rusted out 74 Hilux parked outside did get some some TLC before I even turned the key.