Confused, gearbox/clutch issue!!

[Stani1029]

So i got my gearbox back together yesterday and felt confident that i had done it correctly, fitted new clutch and everything back to the car. And this is what i get!! Difficult to select gear and clutch very light, when i had the gearbox out i could select gear no problems by hand

http://s1038.photobucket.com/user/stani1029/media/IMG_6321_zpsa3e86a7c.mp4.html

When the car is started the car is in neutral and clutch engaged, then you hear a noise change and the wheel stop thats the clutch dis-engaged then the car stalls thats the clutch being engaged again all in neutral!!

Any suggestions?

 

[Belly93]

selector rod in the rong position possibly ?

 

[frank]

thrust bearing unhooked maybe stani ?

 

[Stani1029]

selector rod in the rong position possibly ?

It was in neutral when i put it back together, and once it was built out the car i could select any gear i wanted first time.

thrust bearing unhooked maybe stani ?

I really hope not as i double checked and 100% make sure the lever isnt knocked when i lift the gearbox on.

Honestly its seriously confused me as everything seemed right. The original knocking is away from the gearbox but the new noises are terrible

 

[Belly93]

not sure ive never rebuilt a gearbox, ive stripped one but not rebuilt it

 

[frank]

and where is the bite point stani ?

 

[Stani1029]

and where is the bite point stani ?

It feels quite normal (high like before) when i can get it into gear. The gearbox seems to have similar symptoms as the night it broke.....

 

[r-reg-sr]

get the blindfold guy on it? oh i hope this works out for you !!!!

 

[Stani1029]

get the blindfold guy on it? oh i hope this works out for you !!!!

I am wanting to do this myself but once I take it out again then take it apart, if nothing is obvious to me ill get him to have a look.

 

[davyboy]

Did you dismantle the box and rebuild it ???? Incredibly fine tuned things, no room for error. You may have missed a spacer shim out - have a look on your bench and see if its there - my only suggestion I'm afraid.
I just pay an expert to do it - simpler - best of luck.

 

[--alpina--]

I hope you get it sorted out!!!, i myself wont go down that route messing with gearboxes, just complicated, get it repaired, or bung it in a bin and get another!!


j

 

[Stani1029]

Did you dismantle the box and rebuild it ???? Incredibly fine tuned things, no room for error. You may have missed a spacer shim out - have a look on your bench and see if its there - my only suggestion I'm afraid.
I just pay an expert to do it - simpler - best of luck.

Yeah i did and im 100% sure nothing got away. I done it in my kitchen lol

 

[McMicra]

Could it even be something as small as a spacer put on the wrong way about? ( silly i know )

 

[Stani1029]

Could it even be something as small as a spacer put on the wrong way about? ( silly i know )

Honestly all these little things are passing through my head purely because i dont have a clue what it is. Upon removal i remember which spacers went where, unless somewhere 1 got away but i ask myself how could it have?! lol ill get it stripped AGAIN asap and see if theres anything noticeable.

 

[Stani1029]

Right guys, i got it apart again and guess what it is??

How about i dont have a clue!! there is absolutely nothing obvious, release bearing still on, clutch 100% the right one

 

[r-reg-sr]

i remember a detail'd strip on polyp blog, even with that i wouldnt even have a chance of understanding it

 

[Stani1029]

Lol ive been messing with it for last 20 mins, it seems that if i select each gear and turn the diff that in 3rd and 5th i can continually turn it. Any other gear just locks......

 

[frank]

sounds like a syncro issue to me stani (the balls and springs, or pawls and springs) ?

 

[Stani1029]

Hmm heres what ive found

This is 5th gear in neutral

Then 5th in gear

Then back to neutral (what are the chances?)

Now if it is this that would explain the 20mph wheelspin when on axle stands and the stalling when engaging the clutch and it being difficult to select other gears because its already in a gear?

Is this a pawl frank? Theres 3 of them and i found that 1 isnt sprung.....

One that is sprung

One that isnt sprung

Thoughts?


P.s. Damn my iphone is oily! LOL

 

[frank]

yes thats the pawls eh stani, paul will know what,s what eh

 

[Stani1029]

I await his opinion, tomorrow night ill strip my other gearbox and see if thats any different. I may be because its all loose but i was holding it together when shifting and still the same.....

Really want to know rather than just bin it and get another

 

[McMicra]

I await his opinion, tomorrow night ill strip my other gearbox and see if thats any different. I may be because its all loose but i was holding it together when shifting and still the same.....

Really want to know rather than just bin it and get another

Best way to learn rather than just giving up ae bud, it'll be good experience

 

[SuperUno]

I had a similar issue on a rover box and it was caused by a sticking 5th gear syncro, sounds like your issue could be similar....

 

[pollyp]

first the synchros.
with the bare gear shafts, move the synchro by hand. you should be able to slide it on fully to engage a gear and when you pull it out of gear, it should 'click' back into neutral position and the ball checker should hold/secure it's position.

next most important part that's easy to mess up is the selector gate assembly (24).
-all the synchros must be in their middle neutral state,
-slot the shorter 1st/2nd selector fork arm (23) into the selector cage (24) (obviously cos you can't fit that arm with the cage in the way).
-NOW its important to make sure when fitting the cage onto the bell housing that all 3 selector fingers in the cage are held in neutral and the selector 'striker' peg (21) is located within the 'slot' of the middle finger.
- still keeping the fingers equally in neutral, fit the middle fork (27) and the long fork (14) and the shaft fork (19) to hold it together.
- slide the reverse cog in place and insert the cog axle

- now if done right, you should be able to easily turn the rod in neutral between 1st/2nd and 3rd/4th and selecting 5th/rev should only require slight force pushing against the sprung check spring (4). if it doesn't turn easily between left/right, then the fingers weren't in neutral during fitting and is out of position.
- holding the two shafts steady, engage all the gears and it should feel and appear to engage positively as expected.
- whenever the selector goes into neutral between gear changes, the synchro is moved into neutral and the ball should hold it in position. if you see the previously selected gear synchro 'sag' and unexpectedly slip towards a cog (like the 5th gear synchro pic) while you turn the rod to select one of the other 3 selector fingers, then the synchro ball checker isn't working properly.

next, whenever you push or pull the rod to engage any gear, it is held/locked in place by the selector rods sprung ball check (20) slotting into 1 of the 3 groove valleys at the end of the rod. if a gear isn't fully engaged (whether misaligned fingers or driver error), the ball check won't be fully slotted into the valley to resist back/forth movement, hence could pop out of gear.

 

[Stani1029]

Thanks for that paul, i am sure it is 5th gear causing this. It doesnt click back in place like the rest of the gears do. Heres the selector gate assembly, i am very confident its correct

 

[pollyp]

yea all the fingers n gates look matched, so I'd investigate why 5th gear synchro isn't staying in neutral. missing or sticking ball spring?

 

[Stani1029]

Are you talking about springs on the shaft? As above 1 out of 3 pawls doesnt spring out which could potentially jam the selector?

 

[pollyp]

Are you talking about springs on the shaft? As above 1 out of 3 pawls doesnt spring out which could potentially jam the selector?

yeah the 'shift insert', what's beneath the insert? spring?
according to nissan4u, 3rd/4th and 5th gear synchro uses the same 3 inserts but 1st/2nd is a different part #

I suppose all 3 inserts should be doing the same job equally all round the synchro ring.
if the shaft to synchro gap is tight, the unequal force could jam the spline.
if the gap is loose enough, the slack insert could allow the whole synchro ring to shift offset, relax the other 2 insert springs = less ball spring locking force = ring not held in place.
logically whats the point of having that 1 insert unsprung just to rattle about loosely with no purpose?

in summary the sprung check balls in the synchros helps to hold em in neutral while the check ball at the end of the selector rod helps to hold the selected gear.

 

[Stani1029]

Yeah it doesnt seem right so im going to strip my last gearbox to see if its sprung and has a better click

 

[pollyp]

ok

 

[Stani1029]

Was off work ill today and by midday felt better so there was only one for it! Dug out my spare gearbox, decided against opening it up and put the car back together, all working perfectly damn ive missed it!!

 

[McMicra]

Now to spend a day fixing the gubbed one so you have a spare again + it will give you a better understanding of the box for next time