Gearbox grinding :/

[Wattsy]

So my gearbox started grinding about a week ago and I just wanted to know if anyone knows what's happening before I go and rush off to Perth to get it fixed.:confused:

It's always been stiff changing from first to second but now it's grinding into third but only at certain rpms and it won't change down from fourth. I have read some of the other threads but no one seems to have the same problem.

It's a 2006 6 speed manual - apparently the worst gearbox for the tj

Any help would be great and if you know any mechanic that's good with gearboxes / clutches in Perth that would also be great thanks.

[Mudnguts]

My 6 speed grinds a little 3rd to 4th at certain revs. As for the stiff shifts when did you last drop the oil out of the gearbox? I found that an oil change made shifting a lot smoother and easier.

[victoro]

So my gearbox started grinding about a week ago and I just wanted to know if anyone knows what's happening before I go and rush off to Perth to get it fixed.:confused:

It's always been stiff changing from first to second but now it's grinding into third but only at certain rpms and it won't change down from fourth. I have read some of the other threads but no one seems to have the same problem.

It's a 2006 6 speed manual - apparently the worst gearbox for the tj

Any help would be great and if you know any mechanic that's good with gearboxes / clutches in Perth that would also be great thanks.

I would try spilling out the fluid and get some Royal Purple Syncromax before anything, if the box is ok this will help by miles (I have the same year and same box)

[Wattsy]

I would try spilling out the fluid and get some Royal Purple Syncromax before anything, if the box is ok this will help by miles (I have the same year and same box)

Thanks Vic
I did change the oil to a penrite but it didn't seem to improve it, should I try the royal purple synchromax?

[Jeepkraft]

We have a really good transmission shop we send ours to. Give us a call. 93025367

[Mudnguts]

The 6 speed box is extremely fussy as to what oil it will work with. It must be either genuine mopar, royal purple or redline synchro max. The penright will probably be the cause of your difficulty shifting. Drop it out and you'll probably find the box comes good :)

[bonza]

Thanks Vic
I did change the oil to a penrite but it didn't seem to improve it, should I try the royal purple synchromax?

thats the wrong oil. and wrong oil wont do your transmission any good

read this http://www.ausjeepoffroad.com/forum/showthread.php?t=125368

if damage is done probably the shifter rail and fork assy worn (often caused by aggressive gear changing) and wont let the gears engage properly, or synchros worn out, often caused by using wrong oil

the oil should be changed every 50k in these boxes, contrary to what the owners manual states, which is it never requires replacing unless contaminated by water.
however on other models and JK wranglers it does state to change oil every 50k