Manual Transmission: Hard to get into 4th gear (and somewhat 1st). Diagnosis?

[nobb]

Hi guys,

I've got a 1998 4Runner with the R150F manual transmission. Recently I've noticed there to be a bit of resistance going into 4th gear. I can still go into gear, but dont recall it being that hard before. I also have resistance going into 1st gear, but it's not as bad. All my other gears operate just fine.

Things I've already done:
-Inspected my clutch pedal and performed the linear spring mod on it.
-Shifter bushing and seat replaced
-Transmission fluid replaced 10,000km ago from previous owner by dealer.
-Clutch fluid flushed 5,000km ago.

Just wondering if you guys have suggestions on what to check for? Perhaps it's my shifting linkages? If so, is there a way to adjust this?

Thanks!

 

[steezemcqueen]

How many miles are on the truck?

 

[nissanh]

Before you put into the 4th gear press the clutch twice and see whether you feel the same resistance.

 

[nobb]

300,000km

 

[Singtoe]

Your syncro is worn out or broke, (cracked). The tranny needs to be r/r'ed.

You have one of two options. You can live with it, by speeding up your RPMs to sync the gears together, skip 4th gear all together or r/r the tranny.

 

[nobb]

I wouldnt be suprised if the syncros start wearing out after this sort of mileage. Is it safe to continue driving like this? Strangely, the gears dont grind or anything...it's just hard to push in.

Is there maybe some sort of friction modifier that can be dumped into the tranny? I was also planning on maybe swapping the fluids with Redline MT-90 as I've had good experiences with that on manual trannies.

 

[Singtoe]

Try it and see.


To think about it, if they just changed the tranny oil, maybe they used a synthetic oil, That stuff is super slippery and it might cause the syncro not to grab.

Try the fiction additive. See what happens.

 

[nobb]

YES! FIXED IT! Even though I recently adjusted the clutch pedal, it appears it got loose again. This time I made sure to rotate the rod until the end of the pedal was fully extended in the rest position. Then I tightened the trailing bolt and put locktite on everything.

My pedal feels like it has a noticeably longer throw now. Shifts are silky smooth and like driving a new truck.