NSG370 popping out of reverse

[Toby42]

Alright, I'm not at a loss but sort of confused. I bought a 05 LJR with a 6 speed recently and all works and looks great except for reverse. If I put the car in reverse at just let out the clutch it will grind a little and pop right out. If i give enough gas it will stay slightly longer but still pop out. If and only if I hold the shifter in place will it stay fine. At first I thought it was because the PO had installed a BL and MML but the trans was sitting at stock height on the original skid plate. So I bought a UCF ultra high clearance skid, painted it up and installed it, along with a savvy cable shifter, and replaced fluid in the Tcase and Transmission (RP Synchromax in the trans). Still having the same problem. checked clearance under the boot and im able to engage all the way with no interference.

So after some research I found a thread with someone having the same problem and the thread closed with someone saying something to the tune of "yeah thats just the NSG370 for you, just hold the shifter in place while reversing". Is this true? is there anyone who has solved this problem? I have no problem holding the shifter in reverse if thats the case, it just plucks a certain cord with me.

 

[g.hayduke]

It was a design defect in the early examples. It was corrected via redesigned parts used in the later ones and all the rebuilts.

Here is a link:
https://static.oemdtc.com/TSB/21-001-10A.pdf

I personally had the same issue. I bought a rebuilt from High Impact. I've had no issues since then with around 40k miles on the rebuilt.

Many will tell you the NSG370 is a total POS and to just swap it for something else. I like mine well enough that I have no regrets on swapping in a rebuilt

 

[JKP]

It's a 2005 issue.


TSB NUMBER: 21-006-05
GROUP: Transmission
DATE: February 24, 2005

This bulletin is supplied as technical information only and is not an authorization for repair. No part of this publication may be reproduced, stored in a retreival system,
or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without written permission of DaimlerChrysler Corporation.
THIS BULLETIN IS BEING PROVIDED IN ADVANCE. DO NOT ORDER PARTS OR
PERFORM ANY ACTIONS RELATED TO THIS BULLETIN UNTIL MARCH 07, 2005.
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.
MODELS:
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).
SYMPTOM/CONDITION:
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.
DIAGNOSIS:
1. 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.
2. If the center console and shifter boot are properly installed, and the transmission fails
to remain in reverse as designed, perform the Repair Procedure.
NUMBER: 21-006-05
GROUP: Transmission
DATE: February 24, 2005
PARTS REQUIRED:
Qty. Part No. Description
1 05175903AA Kit, Reverse Gear - 4x4 or 4x2 (inc. internal
shift subassembly, reverse gear, reverse
syncrho sleeve, reverse blocker ring,
retaining snap rings, oil seals, and counter
shaft seal plug )
1 04318083 Mopar® Gasket Maker
2 04874464 Lubricant, Mopar® Manual Transmission
(MS-9224)
SPECIAL TOOLS/EQUIPMENT REQUIRED:
9648 Mainshaft Build Fixture
9633 Build Fixture
NPN 3-Jaw Puller
W-262 Hub Installer
NPN Hydraulic Press
9638 Seal Installer
9635 Seal Installer
9636 Shaft Remover and Installer
7829-A Plug Installer
C-4171 Handle
6448A Bearing Installer - Tube
REPAIR PROCEDURE:
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.
POLICY:
Reimbursable within the provisions of the warranty.
21-006-05 -2-
TIME ALLOWANCE:
Labor Operation
No:
Description Amount
21-00-03-98 Replace Manual Transmission Internal Shift
Assembly And Reverse Gear Components - TJ
3.9 Hrs.
21-00-03-98 Replace Manual Transmission Internal Shift
Assembly And Reverse Gear Components - KJ
3.6 Hrs.
21-00-06-60 Optional Equipment:
4x4 Equipped - KJ
0.8 Hrs.
FAILURE CODE:
J1 Jumps Out Of Gear
-3- 21-006-05

 

[JKP]

It was a design defect in the early examples. It was corrected via redesigned parts used in the later ones and all the rebuilts.

Here is a link:
https://static.oemdtc.com/TSB/21-001-10A.pdf

I personally had the same issue. I bought a rebuilt from High Impact. I've had no issues since then with around 40k miles on the rebuilt.

Many will tell you the NSG370 is a total POS and to just swap it for something else. I like mine well enough that I have no regrets on swapping in a rebuilt

Good to hear your rebuild is holding up. 280K plus mi on my 06 so far.

 

[Toby42]

@g.hayduke @JKP Thank yall, not sure how that bulletin didnt come up when I was searching but thanks again for posting it for me. Sounds like ill just keep my hand on the shifter in reverse until the rebuild!

It has 79k original miles right now, I imagine that will take some time until needing real work done on it.

 

[g.hayduke]

My last straw was being a remote place trying to turn around with front down a steep slope. I wasn't sure I was going to be able to back up to turn around. Bad situation.

When I needed reverse most, it was almost unavailable. Don't wait too long if you go to remote areas alone.

 

[LngJeep]

My 120k 6 speed doesn’t properly engage in reverse maybe 10% of the time. It doesn’t pop out but won’t be engaged from the start. I read somewhere on here about going into 6th and then reverse and that’s made a noticeable difference in my success of it engaging.

 

[Toby42]

My last straw was being a remote place trying to turn around with front down a steep slope. I wasn't sure I was going to be able to back up to turn around. Bad situation.

When I needed reverse most, it was almost unavailable. Don't wait too long if you go to remote areas alone.

Didnt even think of that. Probably would be worth it to look into it sooner rather than later. I'll take a look at High Impact.

 

[NDSpeed]

does the B&M shirts throw help the issues, i remember doing all the research and found that the Short throw shifter is almost required for the nsg370. but memory fails as to why.

also probably a reason the damn thing cost $650 when you can get a short throw shifter for everything else for nearly $150

 

[g.hayduke]

does the B&M shirts throw help the issues, i remember doing all the research and found that the Short throw shifter is almost required for the nsg370. but memory fails as to why.

also probably a reason the damn thing cost $650 when you can get a short throw shifter for everything else for nearly $150

The stock shifter works fine. My original shifter has around 145k miles of adult use and still works perfecty.

 

[Camdenst]

does the B&M shirts throw help the issues, i remember doing all the research and found that the Short throw shifter is almost required for the nsg370. but memory fails as to why.

also probably a reason the damn thing cost $650 when you can get a short throw shifter for everything else for nearly $150

Between the B&M shifter and switching to Redline Im 100% improved. Very occasionally ill grind reverse if it isn't in all the way, but patience is the best remedy for that. I highly recommend the shifter, its way more engaging.

 

[Toby42]

Between the B&M shifter and switching to Redline Im 100% improved. Very occasionally ill grind reverse if it isn't in all the way, but patience is the best remedy for that. I highly recommend the shifter, its way more engaging.

I did look into this, were you able to install without dropping the trans? Im wondering if i could manage a top down approach to it.

 

[g.hayduke]

I did look into this, were you able to install without dropping the trans? Im wondering if i could manage a top down approach to it.

The shifter can easily be swapped from the top.

However, a different shifter will not fix a fucked reverse. The fix for the problems with reverse is internal parts as documented in the TSB.

 

[Camdenst]

I did look into this, were you able to install without dropping the trans? Im wondering if i could manage a top down approach to it.

Yep... 100% top down. Its a extremely straightforward process.

If my memory serves correct: remove the plastic trim and cup holder section, take off the shift knob, then inner rubber boot gets taken out and then there are 4 bolts that hold it into the transmission. Ftom there just swap over the shift level and put it back together.

 

[freedom_in_4low]

I see it oft repeated that it's a 2005 issue but I replaced the NSG370 in my 2006 for this exact issue, so I'm not convinced the new parts actually addressed it, or at least not all of it's possible causes. I chose not to roll the dice on another one and installed a new AX15. I miss the NSG's first gear but the shift feel feels like a Porsche in comparison and I have more peace of mind with gearbox derived from a Toyota transmission that has been in use for 40 years than I ever would have had with a discontinued, value-engineered Mercedes unit.

 

[NDSpeed]

Yep... 100% top down. Its a extremely straightforward process.

If my memory serves correct: remove the plastic trim and cup holder section, take off the shift knob, then inner rubber boot gets taken out and then there are 4 bolts that hold it into the transmission. Ftom there just swap over the shift level and put it back together.

Also a good time to replace the old inner boot with a new one of the $15 Mustang boots

 

[NDSpeed]

https://wranglertjforum.com/threads/03-04-inner-shifter-boot-fix.46803/

found the thread,

@freedom_in_4low , before I installed the NSG, since I was unaware. I had a local shop rebuild it for me. He was an old school guy with decades of experience. He asked.me what upgrades do I want done.
Not the 24year old who said the computer says to replace the sprag clutch and you'll never have a problem again

 

[tnjeepguy]

perfecty

perfectly ??

Mine in my 2017 JK pops out of first gear sometimes, when you don't go into second first.
(trying to get @NovakConversions or Advance Adapt to make a bellhousing+ so JK 3.6 owners can put an AX15 in to replace the 6sp)

 

[g.hayduke]

I see it oft repeated that it's a 2005 issue but I replaced the NSG370 in my 2006 for this exact issue, so I'm not convinced the new parts actually addressed it, or at least not all of it's possible causes. I chose not to roll the dice on another one and installed a new AX15. I miss the NSG's first gear but the shift feel feels like a Porsche in comparison and I have more peace of mind with gearbox derived from a Toyota transmission that has been in use for 40 years than I ever would have had with a discontinued, value-engineered Mercedes unit.

Where did your bad replacement come from?

 

[g.hayduke]

perfectly ??

Mine in my 2017 JK pops out of first gear sometimes, when you don't go into second first.

Mine never pops put of gear. It goes into gear as it should, r, 1-6. It's easy to tell that it is in gear. Shifts fine.

Is it Honda-slick? Hell no. That would be an unrealistic expectation.

I've driven manuals dating from the 50s to 21st century. I have no actual complaints with my rebuilt NSG370.

How do you define perfect?