Transmission issues

[Lka1988]

Hi everybody.. new to the forum.

I have a '91 FJ80, and the transmission seems to have a few weird issues. I'll start with the one that worries me the most.

1. When I shift from Park to Reverse, the entire car "bumps", I guess would be a good word to describe it. I'm not sure if this is the transmission or something to do with the other parts of the drivetrain

2. Possible reason for 1.. The LC has around 228k miles on it, and I don't think the transmission fluid has ever been changed. Would it be a good idea to change it, or would that be too much of a shock to the tranny?


Any help is appreciated

thanks, Lane

 

[-Spike-]

Change it. If something breaks (I can't see that happening) it was gone anyway. Check your u-joints and your transmission and engine mounts.

-Spike

 

[Lka1988]

What would be the best way to change it? Drop the pan? flush and fill? I work at a lube station, we have one of those nifty tranny flush machines, would that be a good idea?

 

[Beowulf]

1. When I shift from Park to Reverse, the entire car "bumps", I guess would be a good word to describe it.

Welcome Lane!

#1 sounds like the very common Land Cruiser clunk which is normal. Read up here on 'Mud about the slack in the drive line. I think searching on Clunk, clank, or klunk should do it.

Could be excessively worn hub flanges exacerbating the normal clunk.

As for the tranny, it is OK to use the "fluid exchange" type of machines where the fluid is sucked in via the vechicle's automatic transmission pump. There has been discussion over the years that those machines with their own pump will create too much crud floating around in the tranny. Do not use additive type of cleaners; just a good brand of ATF. At your mileage I don't think you want to experiment with synthetic ATF in the tranny.

-B-

 

[CJF]

I would drop the pan, inspect, and clean/replace the filter at this point.

Curtis
91FJ80

 

[Grench]

2x U joints.

 

[jcj_78FJ40]

It’s probably driveline slop. My 91 does the same thing. Replacing the front hubs and U-joints helped a little but hardly noticeable.

Acceptance is the key. Now I think I would be more concerned if didn’t here the clunk

But, I’m still going to try this.
https://forum.ih8mud.com/showthread.php?t=68039

Good Luck!

 

[Rusty Phillips]

search transmission fluid swap

basically in a nutshell
-pull both hoses going to the tranny cooler in the bottom of the radiator (one goes in, one comes out, but I dont know which is which)
- aim both hoses into a 5 gallon bucket under the truck
- start truck and see which hose is spewing ATF
- shut off engine
- push a hose barb (IIRC 5/8") into the hose that is pumping out fluid
- slip a 5+ foot long piece of clear hose over the hose barb and route it into a bucket located to the front of the truck (so you can see the fluid coming out & how much is in the bucket while you are feeding the gallon jugs of ATF into the funnel
-get 5 gallons of ATF and a long skinny funnel that will slip into your transmission dipstick
- open the tops of each gallon of ATF so you dont have to mess with it once you start
- have buddy start truck and be ready to shut it off quick
-you pour new atf into the funnel that is in the dipstick, while watching the old stuff getting pumped out into the bucket
- dont cuss if there are kids around when you overflow the funnel & dump ATF all over everything
- have buddy run it (w/ foot on the brake and Ebrake applied) thru all the gears
- shut off engine when tranny fluid coming out looks like cherry cough syrup

you should have enough left over to also do the power steering pump (also uses ATF)

immediately after changing my transmission fluid I went from 12 mpg up to 18 mpg...... and last friday night that hot blond flight attendant that lives next door came over to my place with her girlfriend and a case of Bud light

other than that I really didnt notice much difference from changing my atf

 

[BOZ]

I too am in need of the U-Joints and green grease. My issue is not as bad but I have been searching this site to figure out what the problem was.

You guys were much kinder in helping out this guy as too ripping a new one to the drive line pan guy.

I did change out my blinker fluid and plugged the hole with an extra pair of pink panties.

Cheers

Boz

 

[Lka1988]

As for the tranny, it is OK to use the "fluid exchange" type of machines where the fluid is sucked in via the vechicle's automatic transmission pump. There has been discussion over the years that those machines with their own pump will create too much crud floating around in the tranny.

Alright. Now, I should know this, but I don't...I have no idea if our machine has its own pump, or is driven by the vehicle's pump. It has its own power source, hooks up to the car battery, does that mean anything?


And I think I'm going to look into that green grease stuff, sounds interesting.

 

[Lka1988]

About 5 years ago, my dad took it to a shop, they said that the ATF smelled like it was burned.. They said that if we changed it, it would guarantee that the transmission would break down.

That was one shop.

1. What type of ATF was the shop reffering to, synthetic, Dextron...?
2. What method of changing the ATF would guarantee the transmission breaking down sooner?

I'm at a loss here, I'm getting a lot of mixed results. The pit guy where I work said he would recommend changing it.

 

[fernandol]

I am no expert, but I am venezuelan, and cars down there don't get nearly as good manteinance as they do here. Our golden rule regarding automatic transmissions is to never change the fluid of a transmission if it has not been changed regularly since day one.

 

[GXO]

drain it and drop the pain...easy in a 91.

I did it with mine and cleaned the crap out of the bottom by hand. I then filled it up and drove it for a while, then drained it again, rinse repeat 2-3 times and it was clean and no issues. It was that truck's first change as well.

oh, and you don't need a new filter. The 91 has a metal screen, just clean it off.

 

[CJF]

drain it and drop the pain...easy in a 91.

Absolutely.

Change the fluid. Period. Drain and fill if nothing else, but you really should drop the pan.

What you don't want to do is any sort of "pressure flush"; you said in one post that you're not certain if that's what is at your work. If you're not sure, don't do it.

There's something either in the FAQ or a common thread, or I'll dig it up for you, about how to do a passive full flush with a bucket o' fluid; if you want to go that route, let us know.

If you just ask around to friends, neighbors, coworkers, uneducated grease monkeys, etc., you're going to get every opinion under the sun.

Trust us ,

Curtis
91FJ80
234k

 

[jcj_78FJ40]

Here's another link that pretty much does the same thing as mentioned above.
https://forum.ih8mud.com/showthread.php?t=58291