Grinding in 4th gear??

[metalmonkey47]

Just recently got my LZ together and today was my first time driving it. We put the 4 speed back in since the 5speed was popping out of reverse and needs a rebuild.

 

I noticed, and it's actually getting pretty bad, that in 4th gear once driving for a moment or so that it starts to make a nasty grinding sound, and it sounds exactly as it would if you were grinding into a gear with a worn out synchro but this is a little more faint. 

 

It happens mostly when coasting or coming off the throttle.

 

Any clues? It's got some fresh synchromesh and it was working fine when we swapped in the 5 speed a few months back. This is strange  :geek:

 

 

 

I might also add that with my 5speed I would occasionally hear a slight grind when coming off the throttle in 5th gear that got louder as speed increased, but never moving forward at normal speed. 

[metalmonkey47]

Also, I've flipped my shifter backwards to bring the shift knob closer to my hands and bring the bends towards the back of the truck, instead of the front. Is there any chance that maybe the plastic cup thingy is binding and it's not getting into 4th completely?? 

[datzenmike]

You can only be in or out of gear. In gear you can move, out of gear you don't. The noise you hear can't be gears 'grinding' unless in the act of shifting. Could be bearing noise but fourth is the quietest 'gear' of them all. Check oil level.

[metalmonkey47]

Odd. I thought it sounded strange, since 4th is just a direct drive. Maybe I have something loose around the tailshaft. I'll get a video of the sound and investigate it.

 

 

I added 2qt of synchromesh, which is equal to about 1.9L which is only .1L off the 2L refill capacity. 

[devilsbullet]

my z's 5 speed has been doin this in 1st and 2nd since i bought it over a year ago.  hasn't blown up on me yet, and i haven't been able to put it down to see what the problem may be. i'm kinda stuck in the land of just hoping it doesn't take a shit on me.

[metalmonkey47]

Man I really hope I don't blow this trans up. 

 

I'm gonna try some thicker fluid and see what it does.

 

The Synchromesh is only about 5w or 10w-30 so it may not be doing much when it heats up and thins out..

[I'm BLUE]

Matt --- Is the problem of screetching/grinding/etc you were tracking down before related to this ? ( I can't remember off the top of my head what that was.. )

I'm asking since I deduce that it's the same issue spread across (2) transmissions ? (unless did you use the synchromesh on both ? I've never used the stuff..)

Hope you get it pounded out quick bud ! :thumbup:

Stick some redline in it ! hehe :sneaky:

 

Devilsbullet --- just a friendly thought.. I'd look at repairing that very soon. if you can't... double clutching is satisfying where you can (to me at least).

What rear gearing do you have ?

[metalmonkey47]

I did have this same issue :P 

 

And I did use synchromesh in both! I can't afford to blow up any transmissions right now, and I'm guessing that 90% of the issue is oil weight, so I am going to get some redline or Royal Purple Friday and swap it :fu: I thought it was strange that both transmissions did it, but oil weight was the only thing in common between the two. 

[I'm BLUE]

I did have this same issue :P

 

And I did use synchromesh in both! I can't afford to blow up any transmissions right now, and I'm guessing that 90% of the issue is oil weight, so I am going to get some redline or Royal Purple Friday and swap it :fu: I thought it was strange that both transmissions did it, but oil weight was the only thing in common between the two. 

 

That is strange... I wouldn't believe it would do it in both either until you mentioned that , but at any rate :blink:

Yeah I here ya there ... if you were closer I'd toss ya a trans.

The sooner the better :thumbup: :fu: :lol: :console:

I know this isn't it , but gonna say ... you change your throwout bearing bro ? (sorry had to say it :lol:)

 

Trucks come a long way !! I can "kinda" remember what it looked like when you first snagged it.

[Guest 510kamikazifreak]

 

Trucks come a long way !! I can "kinda" remember what it looked like when you had 3 wheels

[I'm BLUE]

What year/model/make was your 5speed out of Matt ?

[metalmonkey47]

Yeah east coast fails for Datsun parts :P haha

I figure if the common denominator is fluid, that's where I'll start lol

 

the T/O is new... ish? haha well about as new as it gets anyways. 

 

I just keep driving it, and work on it as i come along lol. Bodywork next! 

 

 

Not sure, 100% but I know it was a non-turbo ZX

[I'm BLUE]

Bodywork .... I don't envy you lol ....

 

ah gotcha on the 5spd. Next time your under there licking the seeping trans or random grease (like I do) .. see if it's got 2-casted in "ears" on the back tail-shaft housing around the shifter area (below)  or "1"

2= indicates 79' zx 5spd or earlier 280z.

1= indicated 80' zx or 81-83 (you can tell by the shifter at that point to seperate these to :) )

 

If it ends up being an earlier 79-77 z car transmission ... I'm pretty sure you know , but just a reminder those have "right hand" threads on the rear mainshaft assembly. The giant "NUT" (you'll see when you pop it off) comes loose on some of them :-/ .  The later zx trans are "left-hand" thread to remedy the issue ... I don't know for sure each one personally , but it seems to be the case :)  Symptons are in-line with what you're describing briefly on the 5spd :-/ IDK for sure though just a stab ya know ? lolol

 

I have to replace my throwout ... not because it's bad ... because trans will come out ... and don't want it to come out eber again.....  :sneaky: ... I never did say which one of my millions of datsuns though....  :rofl:

 

Keep it up !! :cool:

[datzenmike]

GL-4 80w90 is called for. Newer trans often use thinner stuff and some 10W30 engine oil!!! Drain that shit.

 

Never use additives. When you said syncromesh I thought you meant it has a new one in 4th.

[metalmonkey47]

GL-4 80w90 is called for. Newer trans often use thinner stuff and some 10W30 engine oil!!! Drain that shit.

 

Never use additives. When you said syncromesh I thought you meant it has a new one in 4th.

 

Yeahhh the synchromesh is what I had, and it was cheap. Same stuff I ran in this gearbox before it was taken out, and it hadn't given an issue yet like it is now, which is strange. I figured it would be okay, but it's obviously not! I'm gonna be swapping for 80W90 or THICKER since our weather is getting hot fast here, and the thicker stuff would probably help cushion all the worn crap in the trans. 

 

Bodywork .... I don't envy you lol ....

 

ah gotcha on the 5spd. Next time your under there licking the seeping trans or random grease (like I do) .. see if it's got 2-casted in "ears" on the back tail-shaft housing around the shifter area (below)  or "1"

2= indicates 79' zx 5spd or earlier 280z.

1= indicated 80' zx or 81-83 (you can tell by the shifter at that point to seperate these to :) )

 

If it ends up being an earlier 79-77 z car transmission ... I'm pretty sure you know , but just a reminder those have "right hand" threads on the rear mainshaft assembly. The giant "NUT" (you'll see when you pop it off) comes loose on some of them :-/ .  The later zx trans are "left-hand" thread to remedy the issue ... I don't know for sure each one personally , but it seems to be the case :)  Symptons are in-line with what you're describing briefly on the 5spd :-/ IDK for sure though just a stab ya know ? lolol

 

I have to replace my throwout ... not because it's bad ... because trans will come out ... and don't want it to come out eber again.....  :sneaky: ... I never did say which one of my millions of datsuns though....  :rofl:

 

Keep it up !! :cool:

 

Goddang man you've been really reading up over the years  :thumbup:   :thumbup:  :fu: 

Pretty sure my gearbox is an early box, because it pops out of reverse, and sounds like a box-o-rocks when backing up. (Surprised I haven't shattered the reverse gear!) 

 

I have an Exedy T/O to go into the 5 speed when I get that rebuilt, so I'm just using an 'old' on right now, but it's only got a few thousand miles on it.It's about a year old. 

 

Gotta find access to a shop press so we can get some rebuilding done, but after that I won't give two shits about my 4speed :fu:

[metalmonkey47]

If you check out this video here, you can hear a little more rattling coming from the trans, that isn't the same noise that I'm describing here, but leads me to believe the fluid is the problem...

 

http://s1095.photobucket.com/user/Yatesphoto47/media/VIDEO0095_zps5bca66d4.mp4.html

[I'm BLUE]

Yeahhh the synchromesh is what I had, and it was cheap. Same stuff I ran in this gearbox before it was taken out, and it hadn't given an issue yet like it is now, which is strange. I figured it would be okay, but it's obviously not! I'm gonna be swapping for 80W90 or THICKER since our weather is getting hot fast here, and the thicker stuff would probably help cushion all the worn crap in the trans. 

 

 

Goddang man you've been really reading up over the years  :thumbup:   :thumbup: Maybe you actually did some work out of the 56 units you own in sitting in the garage.. rather than keyboard jockeying on Ratsun...lol  :fu:

 

Pretty sure my gearbox is an early box, because it pops out of reverse, and sounds like a box-o-rocks when backing up. (Surprised I haven't shattered the reverse gear!) 

 

I have an Exedy T/O to go into the 5 speed when I get that rebuilt, so I'm just using an 'old' on right now, but it's only got a few thousand miles on it.It's about a year old. 

 

Gotta find access to a shop press so we can get some rebuilding done, but after that I won't give two shits about my 4speed :fu:

 

fixed ^^^

 

Thanks. Learning my stuff from datzenmike as well as some other members here , then I had taken shat apart and blowing it up then crying about it.

Oh yeah hybridz.org as well (meh sorta lotta good info there though)... Strangely still not sure what I am doing many times lol.

The more I dig into things the more I learn and reinforce the idea ----> "Ahhh....This is why I shouldn't play with nice things... not so nice naow... $%#%" .... :lol:

 

Yeah a few-thousand miles old is nuttin I'd do that to :thumbup:

( I hadn't thought about packing a "sealed" T/O bearing until joining up on Ratsun a little over 3.5 ? years ago lol. Smart move datzenmike. )

 

Too bad you're clear the fap-hole across in something something GA ... I have me little 12-ton tiny press in the garage ... used it within 10-minutes of getting it home when I bought it :lol: :ninja:

Maybe priority ship it and you ship back when done mmkay ? :rofl: