Talking about a '06 Rubicon 4.0L inline six here where the NSG370 6-speed manual transmission is getting "noisy & fussy" . Mechanic says it needs a new transmission to the rebuild tune of $2,500 ~ $3,000. I hit the Jeep forums for info and am considering a transmission drain & fill as I have no idea when last changed (bought with 80K miles on it) . The Jeep 6 - speed manual transmissions like Pennzoil Synchromesh manual transmission fluid (conventional), the Royal Purple Synchromax and lastly the Redline MTL manual transmission fluids (both are synthetic). * I am inclined to try a drain & fill first - son is discouraged and wants to dump this Rubicom (only 125K miles on it , no rust , body is perfect , new radiator, new clutch , new front & rear seals, and rebult engine top end which were done between 80K and 115K miles) . Hoping to find a : "NSG370 Transmission Whisperer" here who can advise some logical course of action ... Thanks in advance !
Jeep NSG370 6 - Speed Manual Transmission Issues
- Thread starter ChrisD46
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I've heard good things about the Pennzoil MTF in that transmission. I'd give that a shot first.
That seems pretty excessive for a manual trans rebuild. I was under the impression that they are significantly simpler and within the abilities of an enthusiast level diyer.
10 years old and 125k miles make it eligible for a used trans from a scrapyard. It sucks that the trans went after the clutch was done.
I had a 2000 golf 5 spd with what I am pretty sure was original fluid at 200k km. It definitely improved the shift feel when I changed it, but it would still not like shifting into first until it warmed up on really cold days in the winter. You could also try a thicker gear oil. You had better learn to double clutch, because "fussy" sounds like your syncros are toast, mate.
10 years old and 125k miles make it eligible for a used trans from a scrapyard. It sucks that the trans went after the clutch was done.
I had a 2000 golf 5 spd with what I am pretty sure was original fluid at 200k km. It definitely improved the shift feel when I changed it, but it would still not like shifting into first until it warmed up on really cold days in the winter. You could also try a thicker gear oil. You had better learn to double clutch, because "fussy" sounds like your syncros are toast, mate.
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I would look strongly at salvage yard tranny. But 2500+ seems excessive for a manual unless they know of a bad spot requiring extra $$$. I had a auto rebuilt needing major work replacing valve bodies do to no one ever changing the fluid in its 170k mile life for less. Get another opinion or two.
harbor
Site Donor 2024
My Crossfire has the same Benz tranny. After trying everything (including Amsoil Synchro), I finally landed on the linked MB factory fill. I don't know if it'll help your 125K Jeep, but worth a try. Have your bled the clutch fluid?
http://www.needswings.com/manual-transmission-fluid
http://www.needswings.com/manual-transmission-fluid
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Does this transmission spec atf or GL4 gear oil? If it's a GL4 gear oil,give Amsoil MTG or Redline MT90 a try. Rebuild or replace as a final resort.
It takes GL4 Gear Oil however Redline MTL is what is appropriate .
Originally Posted By: aquariuscsm
Does this transmission spec atf or GL4 gear oil? If it's a GL4 gear oil,give Amsoil MTG or Redline MT90 a try. Rebuild or replace as a final resort.
Originally Posted By: aquariuscsm
Does this transmission spec atf or GL4 gear oil? If it's a GL4 gear oil,give Amsoil MTG or Redline MT90 a try. Rebuild or replace as a final resort.
$3200 btw gets you a new transmission from the factory. I'd go that route before dropping $2500+ on a garage bay rebuild that may not take.
But before you give up the ghost I can tell you that tranny is very sensitive to oil level and quality. Half quart low and it shifts like garbage. It is vital that the fill hole is weeping when topping off.
Changing the fluid is as easy as an oil change. I'd drop the fluid hot after a long highway drone and fill with the pennzoil synchromesh and see what develops. If the oil is ancient and cruddy, replace with some redline synthetic after the pennzoil cleans things out a bit. Things may improve over time.
Now that I have the 5spd auto (which I'd thought I'd hate) life is soooooo much better. That nsg was a meh transmission from a bread truck with only 300ish pounds of torque rating. The NAG auto is over 600 lbs iirc. Shifts fast and hangs onto gears when u get into it. Maybe a reprogramming for later shifts and [censored] near perfect for the jeep.
But before you give up the ghost I can tell you that tranny is very sensitive to oil level and quality. Half quart low and it shifts like garbage. It is vital that the fill hole is weeping when topping off.
Changing the fluid is as easy as an oil change. I'd drop the fluid hot after a long highway drone and fill with the pennzoil synchromesh and see what develops. If the oil is ancient and cruddy, replace with some redline synthetic after the pennzoil cleans things out a bit. Things may improve over time.
Now that I have the 5spd auto (which I'd thought I'd hate) life is soooooo much better. That nsg was a meh transmission from a bread truck with only 300ish pounds of torque rating. The NAG auto is over 600 lbs iirc. Shifts fast and hangs onto gears when u get into it. Maybe a reprogramming for later shifts and [censored] near perfect for the jeep.
DdDd : Thanks : Good information and certainly worth a shot ! As I said earlier , I have no idea on the quality or oil level on this transmission ?
Originally Posted By: DdDd
$3200 btw gets you a new transmission from the factory. I'd go that route before dropping $2500+ on a garage bay rebuild that may not take.
But before you give up the ghost I can tell you that tranny is very sensitive to oil level and quality. Half quart low and it shifts like garbage. It is vital that the fill hole is weeping when topping off.
Changing the fluid is as easy as an oil change. I'd drop the fluid hot after a long highway drone and fill with the pennzoil synchromesh and see what develops. If the oil is ancient and cruddy, replace with some redline synthetic after the pennzoil cleans things out a bit. Things may improve over time.
Now that I have the 5spd auto (which I'd thought I'd hate) life is soooooo much better. That nsg was a meh transmission from a bread truck with only 300ish pounds of torque rating. The NAG auto is over 600 lbs iirc. Shifts fast and hangs onto gears when u get into it. Maybe a reprogramming for later shifts and [censored] near perfect for the jeep.
Originally Posted By: DdDd
$3200 btw gets you a new transmission from the factory. I'd go that route before dropping $2500+ on a garage bay rebuild that may not take.
But before you give up the ghost I can tell you that tranny is very sensitive to oil level and quality. Half quart low and it shifts like garbage. It is vital that the fill hole is weeping when topping off.
Changing the fluid is as easy as an oil change. I'd drop the fluid hot after a long highway drone and fill with the pennzoil synchromesh and see what develops. If the oil is ancient and cruddy, replace with some redline synthetic after the pennzoil cleans things out a bit. Things may improve over time.
Now that I have the 5spd auto (which I'd thought I'd hate) life is soooooo much better. That nsg was a meh transmission from a bread truck with only 300ish pounds of torque rating. The NAG auto is over 600 lbs iirc. Shifts fast and hangs onto gears when u get into it. Maybe a reprogramming for later shifts and [censored] near perfect for the jeep.
Per wikipedia - The drain plug (bottom) is a hex 17mm while the fill plug (passenger) is a 14mm hex ... I will have to buy both hex wrenches - do I want short arm hex wrenches or long arm hex wrenches for the Jeep manual transmission drain and fill ?
harbor
Site Donor 2024
Originally Posted By: ChrisD46
Per wikipedia - The drain plug (bottom) is a hex 17mm while the fill plug (passenger) is a 14mm hex ... I will have to buy both hex wrenches - do I want short arm hex wrenches or long arm hex wrenches for the Jeep manual transmission drain and fill ?
This set worked well for me:
https://www.harborfreight.com/9-piece-38-and-12-drive-metric-hex-bit-socket-set-67880.html
Per wikipedia - The drain plug (bottom) is a hex 17mm while the fill plug (passenger) is a 14mm hex ... I will have to buy both hex wrenches - do I want short arm hex wrenches or long arm hex wrenches for the Jeep manual transmission drain and fill ?
This set worked well for me:
https://www.harborfreight.com/9-piece-38-and-12-drive-metric-hex-bit-socket-set-67880.html
Should have a clear shot to both plugs. The Jk had an issue with exhaust pipe blocking drain on some years. Allen wrench sockets with a torque wrench for tightness. Casing will crack and make you cry if you go gorilla on it!
Jeep recommends every 30K drain on severe duty. That's the longest I'd go. You already have more and shifting gets lousy as the fluid ages. Hopefully that's all your problems.
Jeep recommends every 30K drain on severe duty. That's the longest I'd go. You already have more and shifting gets lousy as the fluid ages. Hopefully that's all your problems.
Thanks for the Harbor Frieght suggestion (I have one near by and sockets are cheaper !) ... Yes , I will tighten very carefully to just snug (Ihave a torque wrench but not sure what the torque spec is ?) *Happen to see on past paper work tht the transmission fluid was changed in the last 30K miles but have no idea what the mechanic used ? A cheap as the Pennzoil Sntchromesh fluid is I'm inclined to drain it hot and refill with Pennzoil - this way I absolutely know the right fluid was used .
MolaKule
Staff member
The Royal Purple Synchromax is too thin, about the viscosity of an ATF.
Your better choices are GM Synchromesh, Amsoil MTF, or Redline MTL for 10 cSt@100C viscosity.
Your better choices are GM Synchromesh, Amsoil MTF, or Redline MTL for 10 cSt@100C viscosity.
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I have a NSG270 6 speed manual in my C180K. I don't know how it differs but the MB spec oil in mine (7cSt @ 100 C and 36.3cSt @40C) is a touch thinner than the Royal Purple synchromax.
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