Hublocks do not engage (1 Viewer)

[Omrib]

Hello all....
Just got stuck in a 25 ft 45 degree slope ditch with running water, due to not being able to use 4wd capabilities of the old HZJ73.

Tried engaging the hublocks with no success, they would not engage.

Heard some grinding noises, like when your synchros are done...

Tries to lock the differentials, thinking maybe at least one was locked and would be able to get out on 3 wheels......
Did not happen.

After a few phone calls, when finally found someone close, willing to come and help.....I finally was able to lock (at least one) hub, and get out myself.

Not quite sure what actually happened.

I have just opened the hubs and serviced them about two weeks ago, so did not suspect any potential failure from that end.

Maybe I have packed too much grease in them so that they got "sticky" and the springs were not able to engage the slip yoke/block?

Did this happen to anyone here with the Aisin hub locks?

Never happened to me before with AVM or WARN hub locks.

Will appreciate anyone's feedback, so that I know what went wrong and regain confidence in the old machine.

 

[Rigster]

Sorry to have to ask this, but these are MANUAL Aisin hubs?

I have known the auto/electrical hubs and diffs can be a challenge to engage when you are in a position where you are already stuck. Better to lock everything in BEFORE you go into questionable terrain. Sometimes you may need to move the cruiser slightly forward/backward and everything should lock in place.

I have never heard of a manual hub not engaging. Stiff, sure. But they tend to always go in, which is why most owners will swap out the electrical hubs for the manual. If one is not locking, then I would have to surmise that something was not put together right when you reassembled.

I would suggest grab a FSM and open it up again and make sure all the parts are in correctly, and in the right order. My 2 cents....

 

[oldblue]

This is a video that I put together for my electric to manual conversion, but can be applied to the manual type.

 

[Omrib]

@oldblue , thank you for the informative video.
My hubs are manual but still require a specific position to be reached when assembling, so similar

@Rigster , mine are manuals.
I have reviewed the FSM, however only fully understood the sequence after installing is wrong.....
After doing it right, the FSM seemed much more clear

Checked (while parking) that both were engaging and disengaging, and called it good.

You are correct in your recommendation to enter a fight when you're fully prepared .....
However my front diff is not quite tuned and has a lot of backlash so I refrain from using it unless absolutely necessary.

I know it's wrong, but don't want to have the vehicle immobilized for servicing the front axle before I get all the parts.

I hope it's just the "slight forward and backwards " that was missing as I was already stranded.

If so, than everything is ok
Will update if I find out anything which I consider interesting to share.

Thank you all for the reply and support

 

[Felde]

Too much stick grease may be a reason.
But if you manage to turn the knob free to lock, they should engage as the pivot mechanism moves the clutch in.
'Forth and back' , like on diff lockers, is usually not required.
Too much grease may however take up the free space for the clutch to move. There is a risk to hsve it half engaged then.. Also the splines may just match & hit, which requires a few degree of birf rotation to make them pass, but that is rare and can usually be done by moving into neutral to allow the driveshaft/birf to move free.
In both cases, turning the knob is hard to impossible.

Here are some YouTube clips I found helpful:


Cheers Ralf

 

[Omrib]

Hi @Felde
This is what I thought, however the knob was always hard to move, way harder than the warn sets i had on my CUCV BLAZER with Dana 44 front end or the Nissan terrano 2 (also warn premium).
Also, since the knob pushes the springs (both directions)which in turn push the slip-yoke (locking/engaging part), the engaging action will happen sort of spontaneously when the spring overcomes the grease sticking force the the splines (stars ) aline.

When I turn the front drive shaft by hand, when parked, they engage and disengage perfectly, however when I was in the ditch, and could not play with the drive shafy by hand, I just turned from neutral to 1st gear and then to reverse and back to neutral, while releasing the clutch each time, with only grinding noises (no engagement) increasing my disbelief and decreasing my trust in the machine.

So, since I am new to Aisin (and Toyota, other than 4 years with a 1998 hilux), would you recommend going with warn premium hiblocks, or retain the Aisin (which are more genuine and nice)?

 

[Rigster]

When I was speaking of a bit of forward and back, that was more for the transfer and diff locks. I have never needed to do that for the hubs.

Don't waste your money on new WARN hubs, the Aisin's are great quality, and if it is not an issue with a defective hub, I would just correct what the current issue is. If it is just too much grease, you can fix that without taking it all apart, just pop the cap, gouge some of the globs of grease out of there and put the cap back on.

If you do end up have to replace the hubs because they are defective, then I personally would still go with Aisin, but WARN is a pretty good product as well.

 

[Omrib]

When I was speaking of a bit of forward and back, that was more for the transfer and diff locks. I have never needed to do that for the hubs.

Don't waste your money on new WARN hubs, the Aisin's are great quality, and if it is not an issue with a defective hub, I would just correct what the current issue is. If it is just too much grease, you can fix that without taking it all apart, just pop the cap, gouge some of the globs of grease out of there and put the cap back on.

If you do end up have to replace the hubs because they are defective, then I personally would still go with Aisin, but WARN is a pretty good product as well.

Sounds like a plan....
Will update after I service the front end, replace the ARB locker o-rings for the ring seal and adjust the backlash.

 

[Felde]

AISIN is fine. You probably did a mistake of some sort when reassembling the hubs. Your failed attempt to engage them with that grinding noise may have caused damage now, too. Reopening them and an assessment is imperative now.
Get the service manual and look for some more videos.
Good luck Ralf

 

[Omrib]

AISIN is fine. You probably did a mistake of some sort when reassembling the hubs. Your failed attempt to engage them with that grinding noise may have caused damage now, too. Reopening them and an assessment is imperative now.
Get the service manual and look for some more videos.
Good luck Ralf

Hi Ralf
I will go through the FSM again and the videos before servicing again, but I believe that nothing had changed from last time as they do engage and disengage in the driveway, and I described the noises as "grinding" due to lack of better description....It sounded more like when you shift gears on non-sunchro transmissions, when the gears take their time to engage but gently and without causing any real damage? Not sure if I have described it in a clear way.

So, Next time I will photograph the parts after cleaning so we can see the teeth and their wear pattern and get your (and everyone else interested) advice with regards to the state of the hublocks and if they need replacement.

A strange detail: for one of them, I needed to "reconstruct" the connecting (Pushing/pulling) washer ("Pawl"?) as it was somewhat "Eaten" by the hublock and would not perform its duties (travelling up/down the slope of the guide lever, pushing the spring which engages, pulling the spring which disengage).
I thought of replacing it but saw that it does not have a separate part number, and I would need to replace the complete hub-lock assembly if I cannot fix it.
I had to hammer it a bit on a micro anvil made from a chisel held in a vise, to get all bumps and tabs to look like they're supposed to.
If anyone knows of a way to purchase internal parts which are not designated in the parts catalog, I will be very happy to get that info.
For now, If it still engages and disengages and still holding the springs in place when I open it again, I'll call it good.