Need FJ80 tranny advice

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K

Ken702

10 Year
Joined
Dec 13, 2015
Threads
3
Messages
12
Location
Las Vegas, NV
New to the forum and FJ ownership. I'll try to keep this as short as possible, but it's going to be long. Absolutely scored and picked up a 92 that was sitting in a Vegas back yard for, they said, 3 years for $400. Found registration showing plates expired in 2007. PO said parked it due to front end wreck and tranny acting up. Pulled off bent front bumper and went through getting it home and cleaned up. Found igniter, ig coil, and bracket missing. Replaced those, dry rotted tires, changed oil, plugs, etc. Found 1/2" of rust completely covering fuel pump and entire fuel tank inside. Replaced those and got it running. Now for the part I could use advice on:

Trans fluid on dipstick looked full, red, and smelled good. Was concerned because it sat so long, fuel was beyond horrible, and oil was the same. Spent hours on this forum debating whether to change the fluid and filter and possibly toast it or start it and possibly toast it that way. Decided to try to drive it hope for the best. (PO definitely NOT car people.)

Another factor that concerned me is the fact that under the truck, from the oil pan all the way to the fuel tank was completed covered in dirt-covered grease. Couldn't tell what was leaking so bad or from where. Anyway, didn't notice any dash lights in the beginning but I was able to drive it a little bit. It would go a little bit and slip. Best way I can describe it is it will go a few feet and kind of slip. If you let off the gas when it slips, the idle will drop after a few seconds and it will catch, allowing me to move another few feet before it does it again. Ordered filter and waited until today to drop the pan and take a look.

Today: started it in the garage to back it out to the driveway. Noticed that this time, as soon as I started the engine the AT Temp light was on solid. Backed it out and tried what I saw here and pushed the diff lock button. Still slipped, telling me not the front end. Put it in the driveway, tried to degrease it as best I can and drove it back up into the garage. Light is always on while running now, even cold, when running.

Started pulling the pan but got frustrated with the drain plug and those damn 5 pan bolts towards the front. Did get it to drain but got frustrated on the pan bolts and called it a day.

For those of you that haven't given up on my novel and are still reading, here is where I can use some help. Assuming I don't have a ton of metal in the pan when I finally get it out, what should my next steps be? I have a bunch of fords so I'm obviously ok with working on stuff, but not good with trannys and really want to make this one work. I was thinking of trying to "flush" the fluid out of the lines at the cooler mounted to the radiator with air when I get the pan down, changing the filter, and hoping for the best. The temp light confuses me though. Sorry again for the novel and I look forward to being a part of this awesome forum and my new money pit!
 
As far as the light, it could just be a bad sender. I'd try doing a fluid flush on it after removing and cleaning up the filter and pan. If that works, but it's still shifting odd, try checking the kick down cable for the trans to straighten it out.
 
MrMoose said:
As far as the light, it could just be a bad sender. I'd try doing a fluid flush on it after removing and cleaning up the filter and pan. If that works, but it's still shifting odd, try checking the kick down cable for the trans to straighten it out.
Click to expand...

Thanks for the reply. Never done a flush before. Will running air through the lines in and out of the cooler be ok?
 
Welcome!
Do a search (top right white box) for "Rodney's Flush". This will explain about everything on a complete transmission/torque converter flush. BTW, on a 92 the transmission has a screen for a filter. No need to change it and usually no need to remove the pan. Just pull the plug and inspect fluid and plug for shavings/rust, etc. You may want to remove the pan in your case for a closer inspection. As mentioned above, check and tighten up the transmission kick down cable located on the passenger back side of the intake plenum. This will increase the pressure in the transmission and will firm up the shift points.
 
When you pushed the center diff lock button did the diff lock light on the dash come on? The electronic lock actuator is known to "stick" and if the light did not turn on the diff lock did not engage and it could be a striped drive flange.
 
Thanks for the help everybody! I'm happy to report the flush worked and it runs and shifts great! The AT light is still on, and I have a few other little bugs to work out, but think I scored on this FJ and I'm really excited about fixing it up.
 
SUMMIT CRUISERS said:
Welcome!
Do a search (top right white box) for "Rodney's Flush". This will explain about everything on a complete transmission/torque converter flush. BTW, on a 92 the transmission has a screen for a filter. No need to change it and usually no need to remove the pan. Just pull the plug and inspect fluid and plug for shavings/rust, etc. You may want to remove the pan in your case for a closer inspection. As mentioned above, check and tighten up the transmission kick down cable located on the passenger back side of the intake plenum. This will increase the pressure in the transmission and will firm up the shift points.
Click to expand...

I flush and fill my 92 every year. Complete overkill. I just jack open the drain plug and let it drain out. Then put the plug back in and fill. A couple of years ago I dropped the pan and changed the filter. What a colossal waste of time and money. I didn't know the filter was a screen at the time. I will never do that again.

And I know that by draining and filling I'm not truly flushing the transmission. But I figure I am getting enough of the bad stuff out. And frankly, every time I do it I laugh at myself for wasting the old fluid.
 
Your AT oil temp comes on at 302 degrees and goes out at 248 degrees. There's something wrong with that system if it comes on at startup whether it be the sender or an ele issue. Get this fixed first before you road test.

Once you do a flush the next step is obviously road test. Your tranny only has one solenoid and that's for cruiser control. Outside of that it's a fully mechanical and hydraulic system. If you notice that your clutches aren't slipping on the road test at speeds below 47 mph, great! Take it next to above 55 and test for that speed for a sustained peroid. The lock up clutch in the torque convertor has a friction clutch for engagement. If it slips your temps in the tranny will raise and your AT oil light will come on. This will indicate that your torque convertor needs attention. And by attention I mean a new reman'ed one.
 
120mm said:
What you get when you do that is get pages of results telling you to search for "Rodney Flush".

Not really helpful.
Click to expand...

Here's the procedure:

Remove the transmission plug and drain.
Measure the amount you remove.
Pour back the same amount you removed through the dipstick.
Unhook both transmission lines on the cooler. (Rubber hoses held by clamps)
Direct both in a measured container and start the truck. Can't remember which brings the fluid to the cooler and which is the return.
Shut off the truck when the fluid level gets 1 qt short of your original drain.
Add this amount back through the dipstick tube and repeat.
If memory serves me, you will originally drain about 4 qts. So you will shut off the engine when you pump out 3.
I use a clear vinyl hose and clear gallon water jug that is measured in qt increments.
If your hose is long enough you can easily do this by yourself.
It will take about 22 qts to completely flush the fluid to as new looking fluid.
Very easy to do and works on all vehicles with transmission coolers.
 
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