I have a 2005 X with 33" tires. It only has 50K miles on it. For well over a year I have found that as the transmission gets hot it gets very stiff (difficult) shifting in and out of 5th and 6th gears. It did this with OEM tranny fluid and does it with the Redline MTL. The transmission hump on the jeep does get very warm with highway miles... My buddy has a 2006 JL Rubicon with only 20K miles that does the same thing! We have not been able to figure out what's going on.... We do live in Houston so ambient temperatures a hot! Any help on this would be greatly appreciated!!!
NSG370 Shifts Stiff When Hot
- Thread starter vfserik
- Start date
Welcome to the forum!
What exactly do you mean stiff? Are you "grinding the gears" or is it just really hard to move the shifter from the neutral position to 5th or 6th...or is it hard to move to the far right to get to 5/6th?
Do you have any lift (especially body lift) or engine mount mods on your Jeep? I ask because these can cause body interference with the shifter.
What exactly do you mean stiff? Are you "grinding the gears" or is it just really hard to move the shifter from the neutral position to 5th or 6th...or is it hard to move to the far right to get to 5/6th?
Do you have any lift (especially body lift) or engine mount mods on your Jeep? I ask because these can cause body interference with the shifter.
Thanks Lord Hunnicutt
It starts off shifting as normal but when hot the shifting gets difficult in and out of 5th and 6th only. The other gears remain normal. There is no grinding.
Yes 2" suspension lift plus a 1" body lift. However, it has had the body lift for 8 years and the suspension lift for 12 years.... this phenomenon has been happening for about 2 years. It doesn't prohibit driving but has me concerned....
It starts off shifting as normal but when hot the shifting gets difficult in and out of 5th and 6th only. The other gears remain normal. There is no grinding.
Yes 2" suspension lift plus a 1" body lift. However, it has had the body lift for 8 years and the suspension lift for 12 years.... this phenomenon has been happening for about 2 years. It doesn't prohibit driving but has me concerned....
The first thing I would do is start by replacing the fluid with Redline MTL and see if that helps. It really makes a big difference in the way these things shift (I too have a NSG370).
The synchros may be going, but the Redline won't hurt anything.
The synchros may be going, but the Redline won't hurt anything.
Chris, re-read... he has Redline...
I replaced the stock with the trans that had the fix for the popping out of gear issue years ago (Mine popped out of reverse, had to hold it to keep it in)... before I knew that the problem was just in the shifter, not tranny itself. Put redline in the new trans from the start.
I'd like to know about the heat, when driving, an ice-cold drink will become very hot within 20 minutes in the cup holders. Jeep, once warmed up, never goes above the 210 mark on the gauge. Should I maybe run a dryer duct from the front to dump cooler air to the rear of the engine compartment? Do hood louvers help with this?
Yes I am running the redline already.
Wouldn't the jeep be difficult in 5th and 6th all the time if it were the synchros and not get worse with temperature??? Could it be my shifter that's causing this issue??
As far as heat, my right foot gets uncomfortably warm after about 30 minutes on the highway.... Is this from a hot transmission or the catalytic convertor?
Wouldn't the jeep be difficult in 5th and 6th all the time if it were the synchros and not get worse with temperature??? Could it be my shifter that's causing this issue??
As far as heat, my right foot gets uncomfortably warm after about 30 minutes on the highway.... Is this from a hot transmission or the catalytic convertor?
I wonder if it's your shifter as well, maybe a plastic bushing is getting soft? I was waiting for someone to chime in. My trans is the NSG370 as well, and does not behave as yours is... then again, I did change out the trans in 2014 with a brand new one from MOPAR, so maybe there was a fix for that too. Maybe there is something to what @Lou said about the syncros... My trans would always pop out of reverse, this new trans fixes that issue, so maybe syncros...
As far as heat, I think its a combination of all the heat that is under the hood, all getting trapped at the rear and moving through the tunnel for exit. I'm thinking hood vents and fender vents, like on my JT or on flat fenders might help bleed out some of that hot air.
A hot hump is normal; a warning decal is pasted on it.
The pre-cat and downpipe are nearby, combine that with convective heat emanating from the transmission and bell housing. The main cat is located under the passenger side next to the transfer case. Here's a top side image sort of showing the area under the right foot:
Dynomat is a poor thermal barrier, but it will mitigate heat transfer somewhat.
A Yoga Mat helps, but products designed for thermal shielding are better. https://www.thermotec.com/products/sound-and-heat-barriers
Except for the lack of grinding and specific gear range symptoms, difficult shifting when hot sounds clutch related. Difficult shifting in 5th, 6th, and reverse, along with grinding would be a transmission issue.
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