Can you safely flat tow an HJZ73?

[cruiserkreutz]

I'm looking to purchase a 1991 HJZ73 that is a 5 speed and triple locked. I'd like to flat tow it a bit behind my motorhome. Anyone know if the owners manual reference's flat towing?

Thanks,
Justin

 

[JuanJ]

Hello,

If I remember correctly, the manual recommends using a trailer above 50 km/h (30 mph.) I have to double check.

It is safer to tow it in a trailer.






Juan

 

[FJBen]

There is no “triple locked” HZJ73. Its just locked F/R. Same with every cruiser that is part time 4wd without the viscous coupling full time 4wd tcase

Rant
I don’t know when that buzzword happened from the 80’series crews but I hate it.

No one calls the non locked 80s “single locked”….but they are. They are either locked or non-locked. Yes I know Toyota calls
Them center diff lock.

Rant off

 

[flx]

Would remove rear drive shaft to tow for any noticeable distance.
I think the output bearing is not correctly oiled if the input (and all the gears) doesn't turn so not great to tow in neutral.

 

[Felde]

Hi
I recall there was a long threat on this topic a few month ago. Probably do a search.
And, if I recall correctly, the essence was:
- There is a recommended max flat towing distance and speed from the manufacturer. It's there for a reason. See above. (In essence dedicated to bring the vehicle to safety or repair in case of a breakdown).
- From users that had flat towed theirs, there were equally good and bad experiences.

My 5ct:
The drive train setup of our rigs is quite similar to commercial trucks. And towing experts always remove the drive shaft from a truck when towing on the driven axle. For a professional reason concerning the lubrication. See above.

Cheers Ralf

 

[FJ73Texas]

There is no “triple locked” HZJ73. Its just locked F/R. Same with every cruiser that is part time 4wd without the viscous coupling full time 4wd tcase

Rant
I don’t know when that buzzword happened from the 80’series crews but I hate it.

No one calls the non locked 80s “single locked”….but they are. They are either locked or non-locked. Yes I know Toyota calls
Them center diff lock.

Rant off

Don't be hating my triple locked cruiser.

 

[cruiserkreutz]

There is no “triple locked” HZJ73. Its just locked F/R. Same with every cruiser that is part time 4wd without the viscous coupling full time 4wd tcase

Rant
I don’t know when that buzzword happened from the 80’series crews but I hate it.

No one calls the non locked 80s “single locked”….but they are. They are either locked or non-locked. Yes I know Toyota calls
Them center diff lock.

Rant off

Didn't mean to hit a nerve.

 

[cruiserkreutz]

Hello,

If I remember correctly, the manual recommends using a trailer above 50 km/h (30 mph.) I have to double check.

It is safer to tow it in a trailer.






Juan

If you could actually reference the owners manual, that'd be awesome.

Thanks

 

[FJBen]

View attachment 3315181

Didn't mean to hit a nerve.

I did come off a little unhinged, not blaming you, blaming those 80 series people!!

I’ll try to be more helpful

Here’s what’s in my 88 user manual. Same rules should apply.

Here’s a thread on people flat towing 40s. Same concept.
Flat towing FJ40... Mountains and Apache saga - https://forum.ih8mud.com/threads/flat-towing-fj40-mountains-and-apache-saga.1259412/

And if that’s not helpful, here’s a photo of my dog with a too small lobster outfit on his head.

 

[Rigster]

I'm looking to purchase a 1991 HJZ73 that is a 5 speed and triple locked. I'd like to flat tow it a bit behind my motorhome. Anyone know if the owners manual reference's flat towing?

Thanks,
Justin

I would not.

I would have to assume behind the motorhome, you are looking to travel on the highway? You say a "bit", so would this be a one time thing? Rent a uhaul car hauler trailer (not the dolly). The long term potential issues are not worth the short term time and money savings, IMHO.

If it would be a regular thing, then I would buy a trailer.

 

[Rigster]

I did come off a little unhinged, not blaming you, blaming those 80 series people!!

I’ll try to be more helpful

Here’s what’s in my 88 user manual. Same rules should apply.


View attachment 3315186
View attachment 3315185

Here’s a thread on people flat towing 40s. Same concept.
Flat towing FJ40... Mountains and Apache saga - https://forum.ih8mud.com/threads/flat-towing-fj40-mountains-and-apache-saga.1259412/

And if that’s not helpful, here’s a photo of my dog with a too small lobster outfit on his head.

View attachment 3315187

Every dog needs a lobster outfit! Wait, come to think of it, MY dog does not have a lobster outfit. Does cruiser outfitters sell those?

 

[Behemoth60]

Would remove rear drive shaft to tow for any noticeable distance.
I think the output bearing is not correctly oiled if the input (and all the gears) doesn't turn so not great to tow in neutral.

agreed on the driveshaft.
It's important to note that the manual recommends transmission in N, but Transfer case in H2. My instinct has historically to put the transfer case in N so that the gears are not spinning. However, leaving the transfer has in H2 would have the effect of spinning all the transfer case gears, which would properly lubricate the transfer case bearings. It would also spin the output shaft of the transmission, which should likewise splash lube some of the bearings in the transmission.

The risk of flat towing with the driveshaft attached is that you risk not spinning the gears which is needed to splash the oil up on the bearings. (because your transfer case is in N instead of H2), and the bearings run dry. The H2 transfer case setting should mitigate that risk by spinning those gears and flinging oil.

Indeed, tow truck drivers avoid all this possible damage liability by just dropping the rear drive shaft. It's just 4 bolts and a zip tie to hold it up - cheap insurance.
If you flat tow often, it would be interesting experiment retrofit locking hubs on the rear axles (assuming they are Full Floating style rear axle), or even pull the axle shafts for a long flow tow across the country (again, assuming the rear is Full Float style) . Wait, what am I saying? That is a terrible conclusion. If you have to tow often, put it on a trailer. Trailer tires and bearings are way cheaper to replace than Land Cruiser parts.

Moral of the story - don't flat tow a split case equipped truck with the transfer case in N, as it will run your needle bearings and rear output bearings dry. (I don't know about other transfer cases, but the theory probably applies - this is a very narrowly scoped morality tale!)

 

[Behemoth60]

Rant
I don’t know when that buzzword happened from the 80’series crews but I hate it.
Rant off

To be fair, where there is a differential, one needs a locker.
The 80 series was the first Land Cruiser in history to have THREE differentials. Quite the innovation, to be sure. But now you need three lockers, instead of two.
All my Land Cruisers are proudly 'Double Locked' only.

 

[flx]

agreed on the driveshaft.
It's important to note that the manual recommends transmission in N, but Transfer case in H2. My instinct has historically to put the transfer case in N so that the gears are not spinning. However, leaving the transfer has in H2 would have the effect of spinning all the transfer case gears, which would properly lubricate the transfer case bearings. It would also spin the output shaft of the transmission, which should likewise splash lube some of the bearings in the transmission.

The risk of flat towing with the driveshaft attached is that you risk not spinning the gears which is needed to splash the oil up on the bearings. (because your transfer case is in N instead of H2), and the bearings run dry. The H2 transfer case setting should mitigate that risk by spinning those gears and flinging oil.

Indeed, tow truck drivers avoid all this possible damage liability by just dropping the rear drive shaft. It's just 4 bolts and a zip tie to hold it up - cheap insurance.
If you flat tow often, it would be interesting experiment retrofit locking hubs on the rear axles (assuming they are Full Floating style rear axle), or even pull the axle shafts for a long flow tow across the country (again, assuming the rear is Full Float style) . Wait, what am I saying? That is a terrible conclusion. If you have to tow often, put it on a trailer. Trailer tires and bearings are way cheaper to replace than Land Cruiser parts.

Moral of the story - don't flat tow a split case equipped truck with the transfer case in N, as it will run your needle bearings and rear output bearings dry. (I don't know about other transfer cases, but the theory probably applies - this is a very narrowly scoped morality tale!)

Actually with the gearbox in neutral the output shaft isn't connected to any gear inside either I think (at least no lower part gear). When you select a speed on the gearbox you connect the output shaft to one specific gear.

For the transfer box, I think that the main reason Toyota says to not tow in N it's because in N you are in 4x4 on a Toyota part-time transfer box (not sure on the permanent 4wd types).
So while in N you are not connected to the gearbox, but your front and rear wheels are connected together and obviously it would be an issue to take corners on road. Not even want to imagine what would happen if you try to use a dolly in N...

 

[Felde]

Hehe. The recent discussions on N, H2 and stuff sound a bit like gearbox tetris.
Too much if and when. Cheers Ralf