I fought Hidden Falls, and it won. Help diagnose? (1 Viewer)

[ClassicYotas]

Well I got stuck at Hidden Falls, or should I say, I tried getting into HF. I went over the gate bump and next thing I know it wont go forward. It only worked with center diff locked or 4low. But being in high (normal) in my 80 series didn't help.

So far, this is the damage I know I have.

Blown Knuckle:


Would this cause my car not to move?

 

[ClassicYotas]

More pics of the damage

 

[ClassicYotas]

Now with bonus leaky rear diff!

 

[bloc]

Greasy knuckle balls doesn't mean they are broken. Could just be bad inner axle seals.

If I were you I'd pop the small round covers off your front drive flanges (dead center of the front hub, should be visible with the wheel on if you don't have hub covers). They are about an inch and a half round. In there you'll see the end of the Birfield joint sticking through, with a snap ring on the end.

What year rig is this? if it's an early 80 (91-~93) they had thinner drive flanges and are known to strip the splines. If you get lucky the birf is fine (much harder steel) and the flange is all that's bad. If this is the case when you replace them I'd just get new.. used will likely have wear. You can't upgrade to the thicker ones without also going to the later model longer birfields.

Most of the above only applies if this is an early 80-series.


But yes, you do need axle seals, apparently. Probably time for a front end rebuild.

 

[ClassicYotas]

Greasy knuckle balls doesn't mean they are broken. Could just be bad inner axle seals.

If I were you I'd pop the small round covers off your front drive flanges (dead center of the front hub, should be visible with the wheel on if you don't have hub covers). They are about an inch and a half round. In there you'll see the end of the Birfield joint sticking through, with a snap ring on the end.

What year rig is this? if it's an early 80 (91-~93) they had thinner drive flanges and are known to strip the splines. If you get lucky the birf is fine (much harder steel) and the flange is all that's bad. If this is the case when you replace them I'd just get new.. used will likely have wear. You can't upgrade to the thicker ones without also going to the later model longer birfields.

Most of the above only applies if this is an early 80-series.


But yes, you do need axle seals, apparently. Probably time for a front end rebuild.

It is a 91. So I have that going for me.

Front end rebuild, sounds hard and expensive.

Why is my rear leaking all of a sudden?

 

[bloc]

Front end rebuild is part of the cost of ownership on these things. Usually they go 150-200k, some a lot further, before it's really needed.. not very expensive in the big picture.

No idea on the rear. But that doesn't look like a factory Toyota plug. A new OE crush washer and fill plug is about $8 IIRC so you could try changing that and see what happens. While you have it off check the level..

Also is this a US market rig? 91s here should have a removable rear diff cover.

 

[jbatx]

Interesting... I took a peak at my 91. Rear has a removable cover. Front does not.

Knuckle rebuilds are not hard... Maybe a little time consuming and hella messy. But, not difficult.

 

[ClassicYotas]

Front end rebuild is part of the cost of ownership on these things. Usually they go 150-200k, some a lot further, before it's really needed.. not very expensive in the big picture.

No idea on the rear. But that doesn't look like a factory Toyota plug. A new OE crush washer and fill plug is about $8 IIRC so you could try changing that and see what happens. While you have it off check the level..

Also is this a US market rig? 91s here should have a removable rear diff cover.

No, this is an HDJ81. Japanese spec. Do you know if the front ends are different?

Interesting... I took a peak at my 91. Rear has a removable cover. Front does not.

Knuckle rebuilds are not hard... Maybe a little time consuming and hella messy. But, not difficult.

That's good to know. I appreciate your input.

 

[bloc]

No, this is an HDJ81. Japanese spec. Do you know if the front ends are different?

Not sure, but I'd suspect the front ends are very similar.

The difference in rear end is explained by your rear axle being "full-float" like the 93-97 US models, whereas 91-92 here in the US was "semi-float" which isn't as good. Semi-float is still fine, but full-float is stronger and more durable.

You also MAY have a limited slip differential.. or at least I read about these being possible in JDM vehicles. You'd need to decipher the diff codes to find out for sure.

Beyond that, as long as the ratios are the same (ALL us is 4.10, being diesel yours may be different), I'd bet your rear and front axles are nearly identical to 93-97 US market rigs.

 

[SteveJackson]

The LSD sticker is an indicator you have a LSD unless it's been swapped. Your axle code should be K295 going by memory or K292 for open diffs. The front end is the same as a US truck. The rear would be full float and have disc brakes regardless of year. Knuckle rebuild isn't that hard. Cruiser Outfitters has an awesome rebuild kit that even comes with instructions: Cruiser Outfitters. But that's not necessarily why it's not moving. Could be another axle, t-case or trans problem all together unfortunately.

 

[ClassicYotas]

The LSD sticker is an indicator you have a LSD unless it's been swapped. Your axle code should be K295 going by memory or K292 for open diffs. The front end is the same as a US truck. The rear would be full float and have disc brakes regardless of year. Knuckle rebuild isn't that hard. Cruiser Outfitters has an awesome rebuild kit that even comes with instructions: Cruiser Outfitters. But that's not necessarily why it's not moving. Could be another axle, t-case or trans problem all together unfortunately.

Steve Jackson! Always happy to see you comment.

Yeah, right now I am just looking for a space in Austin to take it all apart, and from there I will see what the damage is.

The truck moves in 4 low, and when the center diff is locked. All the grinding noise comes from the right front side wheel. Do you think the T-case is still a culprit?

 

[bloc]

All the grinding noise comes from the right front side wheel.

Hub drive flange.

 

[Mr Cimarron]

I believe bloc is on the right track regarding checking your drive flanges since you need CDL locked to move.
It also looks like all the oil in your diff went to your knuckles and then it was refilled. I've never seen the grease spewing out of the northern region of the knuckle like that. Better more wet than dry but definitely time for rebuild. I'm about to start one next weekend due to blown inner axle seals with similar leaking, just not as much as yours.

 

[SteveJackson]

Drive flange makes sense. In 4-hi and a busted flange, everything would in theory be trying to turn the broken corner. CDL/4-lo would force power to the rear.

 

[Mr Cimarron]

If it is a simple busted drive flange I have an extra you can have.

 

[ClassicYotas]

If it is a simple busted drive flange I have an extra you can have.

I would greatly appreciate that. Also if you want help rebuilding your stuff let me know. I don't know much but I'm always down to learn and help.

 

[ClassicYotas]

Hub drive flange.

Drive flange makes sense. In 4-hi and a busted flange, everything would in theory be trying to turn the broken corner. CDL/4-lo would force power to the rear.

I appreciate both your inputs. I will report back after I take it apart. I appreciate you guys responding.

 

[bloc]

I appreciate both your inputs. I will report back after I take it apart. I appreciate you guys responding.

Advantage with this failure is it's super easy to check. The truck can even be on all 4 wheels. Pop off the little metal cover on the drive flange and you'll be looking at the end of the birf sticking through. If that's turning (but not the wheel) when you hear the grinding that is your issue.

Note that yours probably needs the earlier thin drive flange and Mr Cimarron's might not fit (I'm guessing at that based on the years of the rigs I thought he has). The later model thick ones rarely fail. You can quickly google images for FJ80 thin vs thick drive flanges to see what to look for.

 

[Mr Cimarron]

Doh! Yeah forgot about the birf difference.

 

[ClassicYotas]

Advantage with this failure is it's super easy to check. The truck can even be on all 4 wheels. Pop off the little metal cover on the drive flange and you'll be looking at the end of the birf sticking through. If that's turning (but not the wheel) when you hear the grinding that is your issue.

Note that yours probably needs the earlier thin drive flange and Mr Cimarron's might not fit (I'm guessing at that based on the years of the rigs I thought he has). The later model thick ones rarely fail. You can quickly google images for FJ80 thin vs thick drive flanges to see what to look for.

I have a 91 Diesel. Do you know if that would make a difference?