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

[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.

 

[JohnnyC]

a few things come to mind about the engine temp issue.... i didn't see mentioned about if you had a fan shroud? solid fan or clutch fan? radiator overflow bottle? burp the coolant system?

driveshafts greased? slip yoke?

imho they (40ś) are loud... but if your concerned its worth looking into

 

[centerlineseal]

Large speakers, ... high volume, ... dinosaur rock. Problem solved!

Drove a '40 for almost 50 years (49 to be exact), most as a daily driver.

That whine under the tunnel is always there. 60 mph is pushing it in a stock '40. My first cross-country trip in a stock '72 with 33K miles was a lesson in driving 55 mph or less

However, ...Kudos to you for chasing your issues. Your in the right place.

 

[CruiserInProgress]

a few things come to mind about the engine temp issue.... i didn't see mentioned about if you had a fan shroud? solid fan or clutch fan? radiator overflow bottle? burp the coolant system?

driveshafts greased? slip yoke?

imho they (40ś) are loud... but if your concerned its worth looking into

Thanks for the ideas.

About the temp increase at speed, I haven't changed the coolant or burped the system yet, but that's on my list. I want to do a proper fmush, including clearing out any debris in the block drain.

The coolant system looks stock, oem (old) radiator, plastic fan w/clutch, fan shroud in place, new coolant reservoir.

About the whining gears while driving, I haven't lubed the driveshafts but will. The gearbox, transfer case and diffs seem to be holding their new oil.

I've been searching other threads since yesterday and will take it out for a few more tests to determine under what conditions the whining occurs (in gear, out of gear, while transfer case is in neutral, during deceleration, noise change during acceleration, etc)

I'm hoping to better pinpoint the issue, if there is one. Could be lots of things, could be nothing out of the ordinary. That 79 transfer case has a reputation of being loud, just seems louder than it should be to me.

After so much time getting the project to this point, road worthy and running strong, I'd like to drive it and have some fun with it, without thinking it's going to self-destruct at any moment.

 

[CruiserInProgress]

Large speakers, ... high volume, ... dinosaur rock. Problem solved!

Drove a '40 for almost 50 years (49 to be exact), most as a daily driver.

That whine under the tunnel is always there. 60 mph is pushing it in a stock '40. My first cross-country trip in a stock '72 with 33K miles was a lesson in driving 55 mph or less

However, ...Kudos to you for chasing your issues. Your in the right place.

What a cool background, to have driven a 40 when fresh and over that long a period.

I was thrilled to just drive it out of the barn for the first time, seats unbolted, rattling doors and apparently only running on 5 cylinders. I figured that out later and was surprised I didn't notice. Gotta hand it to the folks who designed that tractor engine!

 

[peesalot]

Synthetic gear oil does wonders for the gear whine

 

[S.CarolinaFZJ80]

Pull that block drain too. Mine was clogged up and needed a screw driver to break it all free.
You likely have a lot of gunk in the cooling system if the temp is going up with increased load.
Here's some of what came out of my block drain and what I replaced the drain valve with. Hope that helps.
If you choose to open up the cooling system, be very careful with the thermostat housing. Several Heat and Kroil penetrating oil cycles will save you from breaking off a bolt and the water pumps are not made any more

 

[CruiserInProgress]

Pull that block drain too. Mine was clogged up and needed a screw driver to break it all free.
You likely have a lot of gunk in the cooling system if the temp is going up with increased load.
Here's some of what came out of my block drain and what I replaced the drain valve with. Hope that helps.
If you choose to open up the cooling system, be very careful with the thermostat housing. Several Heat and Kroil penetrating oil cycles will save you from breaking off a bolt and the water pumps are not made any moreView attachment 3907500View attachment 3907501View attachment 3907502

Thanks for the suggestion and heads up. I've read about the block block drain and the risks of removing the thermostat housing. I have come to believe in Kroil and my Dewalt impact driver to loosen rusty, stuck bolts. Most of the time it actually works.

 

[S.CarolinaFZJ80]

Thanks for the suggestion and heads up. I've read about the block block drain and the risks of removing the thermostat housing. I have come to believe in Kroil and my Dewalt impact driver to loosen rusty, stuck bolts. Most of the time it actually works.

You could also use carb studs and nut for the thermostat housing. I did a few years ago and never have to worry about breaking a bolt off again.

 

[CruiserInProgress]

You could also use carb studs and nut for the thermostat housing. I did a few years ago and never have to worry about breaking a bolt off again.View attachment 3907521View attachment 3907520

View attachment 3907519

Interesting. Thanks.

 

[SteveH]

Congrats on getting it on the road!

High temps on the freeway (where airflow is excellent) are classic sign of a clogged radiator. I installed an engine that had sat (cooling system open to the air) for years and the rusty chunks promptly clogged my radiator and caused high temps on the highway.

Flushing the system and a new radiator fixed it. You *may* be able to salvage your radiator and have a shop boil it out, but I doubt any over-the-counter radiator cleaner remedies will work.

As others said, be sure the rest of your cooling system is 100% before you blame any one component.

 

[CruiserInProgress]

Congrats on getting it on the road!

High temps on the freeway (where airflow is excellent) are classic sign of a clogged radiator. I installed an engine that had sat (cooling system open to the air) for years and the rusty chunks promptly clogged my radiator and caused high temps on the highway.

Flushing the system and a new radiator fixed it. You *may* be able to salvage your radiator and have a shop boil it out, but I doubt any over-the-counter radiator cleaner remedies will work.

As others said, be sure the rest of your cooling system is 100% before you blame any one component.

That's great info on the temp increase issue and you've identified what seems a likely culprit. I had wanted to at least do a proper flush and cleaning last fall, but ran out of time and decided to wait for spring so I could use an outdoor faucet. That's next on my list!

 

[S.CarolinaFZJ80]

Toyota online parts has a 15% off deal right through Memorial Day. Might be a good time to snag up a new radiator and save a few bucks.

Genuine Toyota Parts and Accessories: Official Online Store | Autoparts.toyota.com

Find genuine Toyota parts and accessories that fit your Toyota. Your source for everything from batteries and floor mats to body panels and engine gaskets.

autoparts.toyota.com

You can't search via year as the database only goes back to 1981 but here is the part number for the non-ac radiator that will work with your 40, 16400-49356

 

[CruiserInProgress]

Toyota online parts has a 15% off deal right through Memorial Day. Might be a good time to snag up a new radiator and save a few bucks.

Genuine Toyota Parts and Accessories: Official Online Store | Autoparts.toyota.com

Find genuine Toyota parts and accessories that fit your Toyota. Your source for everything from batteries and floor mats to body panels and engine gaskets.

autoparts.toyota.com

You can't search via year as the database only goes back to 1981 but here is the part number for the non-ac radiator that will work with your 40, 16400-49356
View attachment 3908689

View attachment 3908690

Thanks for the radiator part number and heads up about the sale at Toyota.

After taking in the many helpful comments here and reading many other threads on both current symptoms (water temp increase at highway speed and loud whining noise in drive train) I hope to try a little more diagnosis on both fronts before investing in too many new parts on my rusty project.

About the possible cooling issue, I ordered a laser IR temp gun to better determine actual temps and check for hot spots. I also want to flush and burp the cooling system and verify function of critical components (thermostat, fan clutch, radiator flow through) and get my heater valve working (it appears frozen open, but I can't feel heat). My radiator appears oem (and old) so that will probably need attention, either a proper cleaning or new replacement.

About the loud whining from the drive train, I plan to put the rear end on blocks and very carefully, attempt to recreate the noise and determine its location (gearbox, transfer case, diff, driveshaft, etc), and under what conditions it is present and loudest.

After I try a few things, I'll report back and go from there.

In my mind, I wanted to minimize my investment of time and money in my rusty project during phase one. My goal was to figure out what worked and what didn't. Then, hopefully get it driving so I could have fun with it and further shake it out, especially during nice weather up here.

Not sure I'll ever get to phase two, but I'd like to do a body off, let's call it a makeover rather than a restoration. It will never be a show car, so it wouldn't be prudent to thrown tons of money at it, but it might be fun to do the patch panel thing, do some sand basting and pretty her up a bit with new paint.

Thats the plan anyway...maybe...someday!

Here's my motivation, and much of the time I kinda need it. Not sure if this one belongs to Adam Savage of Mythbusters, but he has one just like it. Even if mine never looks like this fine example, it's fun to imagine it!

 

[S.CarolinaFZJ80]

Sounds like a good plan. That's a good motivator 40

 

[CruiserInProgress]

Update -

I took her out for another test drive today around the neighborhood and on the highway, briefly hitting 60 mph several times, paying more attention to symptoms.

1) About the water temp rising while at highway speed symptom:

Using an IR temperature gun, I took some readings within 5 minutes of shut down, 10 minutes from highway run.

Thermostat housing 178°F
Radiator top 182
Radiator bottom 144
Oil cooler 157
Coolant port by #5 in head 198
Fluid heat riser 170

There were signs that the coolant reservoir (1/2 full) had spit a tiny amount out of its overflow, but no other signs of possible overheating. My dash gauge increased at highway speed, but never registered over half during short 60mph runs around 2400rpm. I haven't run it longer to see if it continues to climb.

I didn't hear the fan clutch engage at all like I have in the past when working on it. But, I felt a slight resistance when spinning by hand, more than when cold.

So, bad fan clutch, or are my temps not high enough for it to engage yet?

2) About the gear whine more noticeable at higher speeds symptom:

- no whine at all with clutch in or in neutral,
- louder when I let off the throttle at any speed,
- the pitch and volume seems to be the same in 4th gear (the loudest) doing roughly 30mph in 4L as 60mph in 2H. Different speeds, but around the same RPM in both examples.

I pulled off the tunnel cover plate for this test run and it sure sounds like the whining is coming from the gearbox or transfer case, but won't know until I jack it up and run it in 4th. I located a "diagnostic tube" for that purpose.

So, normal gearbox or transfer case sound? Which one would match the symptoms? Is it torque-related, ie. higher torque required in 4th? I haven't tried climbing a hill to see if it gets louder.

 

[pb4ugo]

Your cooling system seems to be working. Just keep an eye on it. The fan clutch needs a lot higher temps. I don't know when, but I would guess something closer or over 200*. Someone might chime in.

I guess it comes to how much whine you can tolerate. They're all gonna whine.

 

[charliemeyer007]

Fluid expands when hot, so it pushes out threw the cap into the overflow bottle. With a proper cap it will suck back in when it cools down. Mine holds like 4 gallons of coolant. I fill/burp the system - it pushes out what it wants, but doesn't suck it back. So I just let it be low until it heats it and its full. Been like that for 40 years.

Gear whine, they were born that way. Maybe the wrong oil in tranny or gear units. On/off gas pedal transfers the load to the other side of the teeth. Perhaps some of the stuff is worn or out of adjustment.

I like simple stuff like my bolted metal fan. In the winter I put a curtain in blocking the lower half of the radiator

The only gauge I trust is my direct read lighted oil pressure unit. I ran fuel hose over the nylon tube from the engine side of the fire wall to the back of the gauge. If the tubing breaks no face full of hot oil - been there since about 1984 - still works great

 

[CruiserInProgress]

Your cooling system seems to be working. Just keep an eye on it. The fan clutch needs a lot higher temps. I don't know when, but I would guess something closer or over 200*. Someone might chime in.

I guess it comes to how much whine you can tolerate. They're all gonna whine.

Thanks for the feedback. If all was working as it should, that would be a first for this project. A refreshing change.

 

[CruiserInProgress]

Fluid expands when hot, so it pushes out threw the cap into the overflow bottle. With a proper cap it will suck back in when it cools down. Mine holds like 4 gallons of coolant. I fill/burp the system - it pushes out what it wants, but doesn't suck it back. So I just let it be low until it heats it and its full. Been like that for 40 years.

Gear whine, they were born that way. Maybe the wrong oil in tranny or gear units. On/off gas pedal transfers the load to the other side of the teeth. Perhaps some of the stuff is worn or out of adjustment.

I like simple stuff like my bolted metal fan. In the winter I put a curtain in blocking the lower half of the radiator

The only gauge I trust is my direct read lighted oil pressure unit. I ran fuel hose over the nylon tube from the engine side of the fire wall to the back of the gauge. If the tubing breaks no face full of hot oil - been there since about 1984 - still works great

It sounds like my cooling system may be working a bit better than yours at this point. No leaks, reservoir doing what it should and temps within acceptable range. I'll try a longer highway test drive and see what the temp does, and keep monitoring it.

About the whining gear noise, I can live with it and hopefully it's nothing I should be concerned about. Fyi, all the oils in the 4 speed transmission, transfer case, both diffs are fresh using 75w90 synthetic.

But, I'm still curious what component may be producing that distinctive whine only with the clutch out and in gear, mostly while accelerating or decelerating and mostly in 4th gear, independent of the transfer case selection.

Once I figure that out, hopefully with a tip from here or by running jacked up in 4th gear and using the diagnostic tube approach, I'll be able to experiment with a heavier oil to see if that reduces the gear whine.

I mostly want to avoid blowing something up now that the project is road worthy. Been a long time just getting to this point. I'd like to enjoy it, for a while at least!

 

[brian]

You'll find that it will hardly whine with no load on it.....like coasting in neutral or with the clutch disengaged.

It's the 3 gears in the xfer.