Hey folks, I have a 5 speed 3.4L 2000 4Runner with about 173k miles. Before changing the transmission fluid which was incredibly smelly, but not dark, I could smell the same odor in the cabin while in 2nd gear and after the truck has been sitting for a few hours after a drive.
After changing the tranny and transfer case fluid, the odor isn't as pungent, but it's still faint of newer gear oil. I located the source at the shifter boot. I didn't see any leaks at the tranny or transfer case.
Has anyone else encountered this? Maybe I will need to take a look under the shifter boot, but I'd like to know before I start taking things apart.
I don't think its much of a problem... I had a similar thing on my Tacoma and never had issues. Also same with my "new" 4Runner, I didn't have any oil smells or anything but after I changed the transfer case, rear diff, and trans oil I could smell a faint new oil smell for the next few weeks. Every once in a while it was a bit stronger and more obvious through the shifter covers. It's pretty much gone away now
Now, I don't have nearly as much experience and expertise yet as a lot of the people on this forum so wait to see what others say. I could be way wrong and it might be an issue you need to fix
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1998 SR5 Tacoma 4X4 with a manual 3.4L - Rolled and TOTALED
1998 SR5 4Runner 4X4 with a manual 3.4L and rear locker
Hey folks, I have a 5 speed 3.4L 2000 4Runner with about 173k miles. Before changing the transmission fluid which was incredibly smelly, but not dark, I could smell the same odor in the cabin while in 2nd gear and after the truck has been sitting for a few hours after a drive.
After changing the tranny and transfer case fluid, the odor isn't as pungent, but it's still faint of newer gear oil. I located the source at the shifter boot. I didn't see any leaks at the tranny or transfer case.
Has anyone else encountered this? Maybe I will need to take a look under the shifter boot, but I'd like to know before I start taking things apart.
I did a vid when I re-did my transfer case... I have an auto but... the transfer case should be the same I think.
it's very common to have that top bushing go bad, they just fall apart after 18 years. I don't know it's not exactly what your asking but maybe it will help you with the top of the transfer case?
Yes, what Andy said above is exactly what I was thinking. I bet the shifter seats for your transmission and/or transfer case are wasted. You could have also slightly overfilled your transmission and/or transfer case that's why it is coming out past the shifter seat.
You can get yourself new shifter seats from Marlin Crawler.
I'm hesitant to say it's the transfer case because before the fluid change, I could smell the really pungent transmission fluid. The t-case fluid did not smell so bad when I changed it out.
Also, isn't it pretty hard to overfill diff/t-case/trans fluid since we need to fill via the horizontal fill plugs? I think the truck would need to be on uneven ground or jacked up to overfill using the fill plugs.
After some more reading, I'm starting to think it's the shifter seal or the gasket for the shifter housing that sleepydad was alluding to.
I'm hesitant to say it's the transfer case because before the fluid change, I could smell the really pungent transmission fluid. The t-case fluid did not smell so bad when I changed it out.
Also, isn't it pretty hard to overfill diff/t-case/trans fluid since we need to fill via the horizontal fill plugs? I think the truck would need to be on uneven ground or jacked up to overfill using the fill plugs.
After some more reading, I'm starting to think it's the shifter seal or the gasket for the shifter housing that sleepydad was alluding to.
Would the transmission breather cause an odor?
You are pretty much right that you can't really overfill it as long as you are doing it on level ground. But, maybe the ground you're on isn't as level as you think or your rig has a positive rake due to a suspension lift.
Sometimes the breather can puke out gear oil if it's overfilled and that's when you might smell it. The breather working normally letting excessive pressure escape probably wouldn't generate a strong smell. It's most likely a worn shifter seat or a leaking gasket that seals the shifter housing to the transmission.
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You are pretty much right that you can't really overfill it as long as you are doing it on level ground. But, maybe the ground you're on isn't as level as you think or your rig has a positive rake due to a suspension lift.
Sometimes the breather can puke out gear oil if it's overfilled and that's when you might smell it. The breather working normally letting excessive pressure escape probably wouldn't generate a strong smell. It's most likely a worn shifter seat or a leaking gasket that seals the shifter housing to the transmission.
I'll order the Marlin seats for the t-case and trans. We'll see how it goes. $15 for shipping those seats and a HD shifter socket is borderline highway robbery...
I finally got around to replacing the shifter bushing with the Marlin one. The old one didn't look bad and neither did the housing seals. There isn't much noticeable difference in terms of the smell as there's still a faint smell when accelerating and a strong smell when entering the cabin a few hours after a drive.
I did notice some air flowing from the boot into the cabin. When the shifting assembling was taken out, it seems that there isn't much to prevent this.
I did notice some air flowing from the boot into the cabin.
Uhhh... the boot on the transmission to the shift lever should be sealed AND the boot from the shift lever to the body should be sealed. Is either/both ripped/torn or not sealing?
-Charlie
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FYI everyone: The OEM shifter seat and bushing for these trucks are fine. Apparently they do disintegrate after a long time, but I pulled what was presumably the original one out of my 97 after 16 years and it was still in good shape...no disintegration was observed. I replaced it with an OEM unit as preventative maintenance. There's no need to use the Marlin one.
FYI everyone: The OEM shifter seat and bushing for these trucks are fine. Apparently they do disintegrate after a long time, but I pulled what was presumably the original one out of my 97 after 16 years and it was still in good shape...no disintegration was observed. I replaced it with an OEM unit as preventative maintenance. There's no need to use the Marlin one.
The marlin one works well and is much cheaper though!
If you are getting air flow into the cabin with the windows up you might want to check the vent flapper under the drivers rear quarter bumper to make sure it is still there. All 3 runners I've wrenched on were missing the cover. Vent behind rear bumper
Uhhh... the boot on the transmission to the shift lever should be sealed AND the boot from the shift lever to the body should be sealed. Is either/both ripped/torn or not sealing?
-Charlie
I think Charlie has it here. There really shouldn't be any smell coming through. We live in ours for extended periods and it is smell free in this regard. Is the top of your transmission covered in oil or something?
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-1996 4Runner. 3RZ 5-Spd. 4x4 Base model. OME2906/Toyota OEM rears with 2004 Tacoma Dual Rate Fronts on Bilstien 4600s.
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Uhhh... the boot on the transmission to the shift lever should be sealed AND the boot from the shift lever to the body should be sealed. Is either/both ripped/torn or not sealing?
-Charlie
After messing around with transmission/tc fluid changes and cabin mods/swaps I, too, had the unwelcome smell of gear oil in the cab.
I googled it and found this thread. I didn't have to look further than the body rubber boot, it was out of the groove on the shift lever and "leaking" gear oil stench.
Easy fix. Thanks, team!
Quote:
Originally Posted by mtbtim
Yes, what Andy said above is exactly what I was thinking. I bet the shifter seats for your transmission and/or transfer case are wasted. You could have also slightly overfilled your transmission and/or transfer case that's why it is coming out past the shifter seat.
You can get yourself new shifter seats from Marlin Crawler.