79 FJ40, first test drive at 60mph - gear noise, water temp increase questions (5 Viewers)

[CruiserInProgress]

I finally got my rusty 79 desmogged FJ40 project road worthy, sort of, and put tags on her. She had been sitting for more than a decade and abused before that.

After a lot of tinkering and some new parts it seems to start well, idle well, accelerate well, doesn't smoke, shifts well (2wd and 4wd) and tracks well. The brakes are next on the list, but it seems to stop OK with the old stuff.

It came with a lift and 15x33 BFG tires, and I upgraded to a FJ60 ignition, but the rest of the drive train seems to be mostly stock (desmogged 2F engine, 4speed gearbox) and stock diffs based on highway performance numbers. I have changed gear oil in both diffs, gearbox and transfer case. The fluids were dark and kinda bubbly, but no metal chunks found.

So, during my first highway test drive this afternoon, two things concerned me:

1) Gearbox or transfer case whining?

In 2H, at 60mph (2500rpm) the overwhelming sound in the cab was coming from the area of the gearbox/transfer case. A high pitched whining is always there while driving, but the pitch and volume increased with speed and was even more noticeable at 60mph. I had verified previously
that the front diff is not engaged and the front drive shaft is not spinning while in 2H. Does that loud, whining sound seem normal?

2) WaterTemp Increase at highway speed?

Water temp increased from 1/3 to 1/2 on my gauge during each 60mph (1/4 mile) test run, then back down to 1/3 when I slowed. That doesn't seem right to me. The fan seems fine, the reservoir/radiator didn't boil over or smell hot and there are no apparent recent leaks. I have not yet flushed the cooling system or cleaned out that block drain, but the coolant seems clean and green. The stock oil pressure gauge indicates there is pressure. And there are no other obvious symptoms, although I may have heard a slight squealing sound from the area of the water pump.

So, what could be the issue elevating the water temp at 60mph? I kinda don't want to drive it at that speed without figuring that out first.

Thoughts?

By the way, I have read that some found driving a short wheelbase FJ40 with a lift and tall tires at highway speeds a bit "exciting". I now know what they meant.

 

[CruiserInProgress]

You'll find that it will hardly whine with no load on it.

It's the straight cut gears in the xfer.

Thanks.

So, the transfer case is the source and that's normal? I've read the earlier transfer cases were especially loud, but the 79 was supposed to be still kinda loud, but a bit quieter?

 

[brian]

Sounds like this?

 

[CruiserInProgress]

Sounds like this?

Yes! Thanks very much for the clip!
And same specs as mine: 2F, 33's, 3.70.

That's definitely the whining gear sound and when I hear it most. It's louder than the engine or tires at highway speed.

What year is yours?

 

[S.CarolinaFZJ80]

Mine sounds about like Brian's although a bit less spry. @brain you desmogged?

 

[brian]

75, yes completely unburdened.

 

[CruiserInProgress]

Thanks for all the feedback and suggestions!

After listening to Brian's video of the same gear whining that I hear on my 79 similarly configured, I'm optimistic that gear noise may be normal. And I'm good with that!

However, I want to continue working through suggestions, inspections and maintenance before spending too much time at highway speeds.

Today, I lubed the U-joints and checked play in the drive train. The U-joints all seem ok in terms of play, but took a fair amount of grease, so I'm glad I finally got to it. No obvious visible issues in the U-joints, slip joints or shafts, other than a thick coating of grease baked on over the years.

Two questions:

1) There was a very slight rotational play at the input to the rear diff, a couple of degrees or so. Is that typical? No seal leaks there.

2) There was a slight, but noticeable up/down, left/right play at the forward output shaft of the transfer case (see pic), less than 1/8" total deflection by hand. Rotation of the front drive shaft is smooth and easy. Does that seem ok? Again, no obvious seal leaks there, so maybe ok at this point?

About oil leaks in general, I get an occasional drip from the rear output of the transfer case (dripping from the e-brake housing), and minor leaks from the engine front and rear main seals, but not much else that I can see. All new oil in engine, gearbox, transfer case and diffs.

 

[pb4ugo]

Usually there's some rotational play in the diffs. It's the spider gears moving on the center pin and loading against the carrier case. Neither of the tcase outputs should wobble. The rear output seal is probably leaking. You might want to address that. It will soak the brake shoes. A couple of vendors sell an upgraded double seal housing. It's not overly expensive, you do have to send your old one as a core.

 

[CruiserInProgress]

Usually there's some rotational play in the diffs. It's the spider gears moving on the center pin and loading against the carrier case. Neither of the tcase outputs should wobble. The rear output seal is probably leaking. You might want to address that. It will soak the brake shoes. A couple of vendors sell an upgraded double seal housing. It's not overly expensive, you do have to send your old one as a core.

Good to know about the rotational play at the diffs being normal.

About the leaking rear seal on the transfer case, the e-brake didn't do much when I tested it, so brake shoes soaked in transfer case oil would explain that. I have the seal, but have been putting off the repair.

About the wobble in the front output shaft of the transfer case, would that be a worn bushing or bad bearing, and how difficult would it be to correct that problem? Can it be done without pulling and splitting the transfer case?

 

[pb4ugo]

It could be as simple as tightening the nut, or could be the bearing. I think you can just pull the frt output housing. I think it's a stub shaft and the shift collar for 4wd is there.
You should probably download a free factory service manual (fsm). I think @charliemeyer007 knows where to find the link.

 

[charliemeyer007]

Land Cruiser Factory Service Manuals (FSMs)

Factory service manuals (FSMs) for your Toyota Land Cruiser ! From the 1950s to the present!

www.cruisercult.com

 

[CruiserInProgress]

It could be as simple as tightening the nut, or could be the bearing. I think you can just pull the frt output housing. I think it's a stub shaft and the shift collar for 4wd is there.
You should probably download a free factory service manual (fsm). I think @charliemeyer007 knows where to find the link.

Thanks, I'll dig into the FSM and see what's involved. Hopefully, it's not too bad to correct. In the interim, I'll avoid engaging that front drive shaft.