Just bought my wife a Jeep and 2nd gear syncros is worn

[Duk]

Used to have similar problem in my 99 TJ - changed to Redline Oil - problem went

[bonza]

without knowing exactly what oil is in your transmission it seems your synchros are probably worn a little and when the oil is cold and thick this makes changing difficult causing the gears to grind. the oil thins out when warm and makes shifting easy.

therefore the best solution would be use a good synthetic oil designed for smooth shifting

Redline MT-90 are ok to use in the five speed NV box you have and being more stable across a wide temperature range should cure your problem

[CleanGetaway]

This vehicle will not be going 4WDing or anything and I am located on the Sunshine Coast, QLD. Nice warm temps!

[markg]

first step
-oil change with the right oil !!

[CleanGetaway]

So where do we get these $1000 gearboxes from? Can you provide a link or any information about this??

Thanks

[CleanGetaway]

So....I have done a fair bit of research and a lot of people out there that have had the same issue as me have switched to using the Redline MT-90 oil which is 75W90 which is hard to believe as it's a much more heavier oil than what is recommended for this kind of gearbox...thus wouldn't it make it worse to change gears?

I'd love to just keep changing oils in hope of stopping the crunching but we're looking at around $90 a pop.

[VooDoo2]

A rebuild kit with new syncro's and bearings is around $350. There is a 5 part video on youtube on how to do it. its actually VERY easy.