2nd gear grinding ONLY when hot.

[Anthony]

My 93 Nissan Hardbody 4 cyl 2wd started this about 3 weeks ago. Going from 1st to 2nd when its cold is no prob.

I drive about 18 miles to work and when I leave the first light and do the 1st to 2nd shift it grinds almost everytime unless I wait for the RPMS to drop.

Just to try to eliminate some possibilities, tranny fluid was changed from Redline MT90 to fresh Amsoil MTG ,and the clutch master ,and slave cylinder were both replaced. Still doing the same thing. 1st thing I thought was the 2nd gear synchro ,but after talking to some people some are saying it might be the
clutch or some of the related components. Something about it not releasing properly. What do you guys think?

It dosent slip. Thanks for any feedback!

 

[LargeCarManX2]

Does it call for "GL-4 rated gear lube?

 

[Anthony]

Yes GL4 is the spec for this truck.

 

[oggb]

Sounds like a candidate for some Synchromesh.

 

[Anthony]

My buddy ran that in his Hondas ,and his EVO ,and LOVES it.
Im not sure about the EVO specs ,but I know the Honda dosent require the EP additives that Nissans do.

Thats whats holding me back from trying it.
Has anyone on here used Synchromesh for a extended period of time in a Nissan tranny?

Please speak up!

 

[The motor guy]

drop it into neutral before going into second and see if that solves the problem until you can fix it. Just so you don't tear anything up in the mean time.

 

[Anthony]

Yeah thats what I do or just let the rpms drop.
Im going to take it to Aamco this week and let them do whatever they need to.

Does it make sense that it might just be a clutch issue?

 

[mechtech2]

Clutch pedal height, freeplay [very important], and a good bleed are first on your list.
Then check your fluid level carefully.

Did Amsoil really get in the tranny? Did someone put in something else?

 

[Anthony]

Yes Amsoil is in there.
I did all the work myself starting with a good bleed on the old components.
I then installed the new Slave ,and Master Cyl.

As of last night the grind has stoped! Go figure!
I installed these components on Sunday ,and on the test drive it still grinded.

On the way to work today I did a few higher rpm quick shifts, and as of now all is well.

So my guess is its time for a clutch. That will be next on the list.

 

[Kiwi_ME]

I used MTL in my '91 Nissan 4-cyl pickup and it still shifted smooth as silk at 85k miles. The slave cyl did fail around 70k however.