Hi, thank you for choosing Justanswer, I look forward to helping you resolve your issue. first off when you had the problem with reverse hopefully they followed this bulletin and replaced everything listed in it. As far as the u-joint going out, that would not be related to the trany issues. You can always find aftermarket equipment that may or may not be as good as the original so I never recommend anything but original equipment. There is no bulletin on it popping out of 1st gear but what ever is causing it could very well be the source of the vibration also. If you are under one year or 12,000 miles the trany work should still be covered under the warranty.
DATE: February 24, 2005
THIS BULLETIN IS BEING PROVIDED IN ADVANCE. DO NOT ORDER PARTS OR PERFORM ANY ACTIONS RELATED TO THIS BULLETIN UNTIL MARCH 07, 2005.
Upon shifting the 6-speed manual transmission into Reverse, the customer may notice that reverse gear may not remain engaged.
This condition may follow/develop shortly after an accidental mis-shift into reverse has occurred. While the vehicle is moving forward and already in a forward gear, instead of shifting into another forward gear the reverse gear is incorrectly selected. Though reverse can not be obtained during the mis-shift attempt, damage to the internal shift subassembly and reverse gear may occur which may later prevent full reverse gear engagement when reverse is selected properly. The customer should be made aware of proper shift procedures.
This condition may also occur if the center floor console and/or shifter boot are not positioned properly.
I see the bulletin did not come through so I am attaching it here.
SUBJECT:NSG370 6-Spd Transmission - May Not Remain In Reverse Gear When Selected
OVERVIEW:This bulletin involves replacing both the internal shift subassembly and the mainshaft reverse gear components.
2005 (KJ) Liberty / Cherokee
2005 (TJ) Wrangler
NOTE :This bulletin applies to vehicles equipped with a NSG-370 6-speed manual transmission (sales code DEH).
Verify that the center floor console and shifter boot are not preventing the transmission shifter from fully engaging reverse. Verify that the console is centered properly to the shifter. Verify that the shifter boot is installed properly.
If the center console and shifter boot are properly installed, and the transmission fails to remain in reverse as designed, perform the Repair Procedure.
SPECIAL TOOLS/EQUIPMENT REQUIRED:
Replace the manual transmission internal shift subassembly and reverse gear components. Refer to detailed disassembly and assembly repair procedures in TechCONNECT which are available in Group 21 - Transmission and Transfer Case / Manual Transmission - NSG370.
If all they replaced was the reverse synchro and not the entire internal shift assembly you could end up with problems in other gears.
Thanks. I will have to find the paperwork on the transmission repair... I think it was over a year ago, though. When it pops out of first, it usually does it when accelerating, so it is really violent. It sounds and feels as if the vehicle is struck by another car, and after it happens the driveshaft/u-joint (or whaterver it is) sounds and feels worse.