Stuck in 3rd gear

[Matty450]

Any help would be much appreciated lads

Over the last month or so noticed my ute was feeling a little sticky in 3rd gear. As in it would change into 3rd fine and would drive fine but if I was slowing down for an intersection and going back down the gears it wouldn't want to disengage.
I would just give it a little yank and continue driving this wouldn't happen everytime so I just put it down to it being a little dicky till it warmed up.

Yesterday however, after the car ran fine the following day I hopped in and went up through the gears until I went to exit 3rd and reach for 4th when it locked into 3rd and would not release until the vehicle came to a complete stop and the revs dropped 750 rpm.

I've tried holding the clutch in while rolling along the road to drop the revs to 750 then change out but it won't let me.
I have also tried changing through the gears without using the clutch by matching the rpm with road speed and it still locks in 3rd.

basic points
-no problems with any other gears (currently driving around by missing 3rd)
-when selecting 3rd it is just as smooth transition as any other gear
-no weird noises
-once in 3rd vehicle drives fine
-if vehicle is turned off it will go through all gears without any issues
-if coasting down highway and hold clutch in I can enter and leave 3rd as much as I like, it is in only when gear is applied by releasing clutch it locks

I called local wreckers and have found another gearbox for $1200 that has done 80grand

I'm planning on removing the gear box and pulling it down to have a look at it. I can tell you right now I'm not going to know what I am looking at but am hoping something jumps out and catches my attention.

I'm looking for any information on possible issues and solutions.
I haven't purchased the gearbox yet, what are people's thoughts on the price of that?

 

[tweak'e]

first thing i would do is change the oil and check for any bits in it.

 

[ShortyNavros]

People seem to rave about the nylon n70 diff/gearbox treatment so if you change the oil you could bung some of that in also, I have no personal experience using it though

 

[TurboSuzi]

Any resolve on this Matty? Mine has exact same problem that started about a week ago. Would love to know if there is any fix to this, or whether the box has to be changed...

 

[luke91]

I had my boxed changed from a box that I was told that was good and now having the exact same problem. Any advice would be good thanks

 

[tweak'e]

what oil are you using ?
and what was the clutch spigot bearing like and clutch release bearing?

possibly an oil issue not letting syncro's work or excessive sideways pressure on the input shaft.

 

[luke91]

I had a mechanic do it and the misses to pick it up. In flat out at work sowing and don't get any service out there so I'll try and ask them on Monday. Because I supplied the box there pretty much rubbing there hands with it. But I'm convinced there's nothing wrong with the box

 

[Rallydudeman]

Hey all
Wondering if anyone ever got any resolution with this or have any more info to add.. Mine's doing exactly the same.. just third gear.. Just spoke with a gearbox guy who said its not a common problem, but alas i log onto here and others have had the same issue..
i'm due for a new clutch anyway, so the box needs to come out at some stage anyway.. but it'd be interesting to know what the solutions have been for others
cheers all

 

[dattorob]

Yeh happened to mine a year ago or so swapped for another 2nd handy from memory spigot bearing was buggered and maybe clutch release bearing and there was something else something to do with that top loader design anyway replaced clutch whilst at also I had replaced gearbox fluid with high quality synthetic regularly but who knows as I bought the rig with over 250k on it already

 

[Horatius]

Yeh happened to mine a year ago or so swapped for another 2nd handy from memory spigot bearing was buggered and maybe clutch release bearing and there was something else something to do with that top loader design anyway replaced clutch whilst at also I had replaced gearbox fluid with high quality synthetic regularly but who knows as I bought the rig with over 250k on it already

You have to be careful what oil you put in these and while "full synthetic" sounds great, it might not be. From memory these are designed to take an older GL-4 spec mineral based oil. At least the earlier zd30 models are,not sure of the later models. Have heard of people putting the "latest greatest" oil in them and having all sorts of problems.

 

[dattorob]

You have to be careful what oil you put in these and while "full synthetic" sounds great, it might not be. From memory these are designed to take an older GL-4 spec mineral based oil. At least the earlier zd30 models are,not sure of the later models. Have heard of people putting the "latest greatest" oil in them and having all sorts of problems.

OK I did use GL4 but not mineral, maybe you got a point there

 

[Horatius]

OK I did use GL4 but not mineral, maybe you got a point there

I could be wrong about the mineral/synthetic part as it was a while ago and old age has its effects. But I know after researching, I found mineral oil was the go and there was a reason but again, can't remember why, so might be wrong.

One problem is that people can put GL5 spec oil in thinking it equals or surpasses GL4, but it doesn't it's a different thing. I imagine people who get their local mechanic to change transmission oil will could get anything (probably whatever is cheapest lol).

 

[dattorob]

Yeh agree, I'll give it a go. I was being too kind to my gearbox