Hi! I just started noticing oil spots under my truck. It’s not right under the engine. It’s further back. The crossmember is wet, and I think the thing above it is, too. I’m clueless! I don’t know anything about auto mechanics, so I thought I would reach out on here since I have a couple good photos. If anyone knows what this looks like, I’d appreciate it. Then I can call my auto repair shop and explain what I think is going on.

I put rocks on the oil spots so I could see where they were coming from. This rail across undercarriage is wet.

That “thing” in middle of photo looks wet. What is that part?

 

Unfortunately, oil leaks form old cars are part of life. They are difficult to pin point and seldom easy to "fix". Hot oil is to subject to gravity, and airflow, which is substantial, especially at highway speeds. Most likely leaks point are at the front and rear crankshaft oil seals. Those seals are usually "lip seal type. As they age, they lose effectiveness. Other possibilities are timing case, valve cover(s), oil pan, etc.

"That part" looks like possibly the aft end of an automatic transmission to me. Is your an automatic? Forward of that item looks clean and dry. Has your transmission been serviced lately? Engine oil becomes darker as it ages in service. Automatic transmission hydraulic oil is probably red in color. Manual transmission oil is usually thicker, and has a lingering odor. Nasty stuff.

If you take it to a good mechanic. he might be able to track down the source of the leak if its obvious. If its not obvious, he will probably caution you that it could become expensive to find and fix. There are additives that you can add to engine oil to stop leaks. Sometimes referred to as a variety of "snake oil". I don't know if they work or not. So-called "high mileage" engine oils supposedly are useful in suppressing leaks in older engines.

My '89 has a mild leak. I have a sheet metal drip pan in the garage, and one that I move under the vehicle if I have to leave it parked on the driveway. I just live with it.

 

Thanks for your reply. Truck is a manual transmission. I had a "new" rebuilt transmission put in 2016. Sent my brother the photos, and he thinks it might be the rear transmission seal. Yesterday was a holiday. I'll call my auto shop today... With the scarcity and cost of new cars, it's more important than ever to keep my little truck going -- best purchase I made 29 years ago!

 

That makes sense. I would expect that a new seal was installed, but possibly the area on the yoke where the seal runs against is worn and now won't seal.New yoke and seal (there may be "Speedi Sleeve") too https://www.skf.com/us/products/indu...-speedi-sleeve

 

Yeah, these old trucks are treasures. Mine's a "beater" and I'm always getting questioned: "Do 'ya wanna sell it"? NO.

 

I get that question a lot too. ALL my trucks. The pickup, which is a beater, too, goes to my middle daughter, and then to her oldest son after that. I've spread it around my 87 4Runner is up for sale for $5,000.00. First cash in my grubby big paw takes it. Already had 3 queries on it.

That leak...
Are you sure it's engine oil, or is it tranny oil? You can tell by the smell. If you need an example, it's easy to get one of the engine oil. Just pull the dipstick and give it a sniff. If the oil you see smells like that, it's engine oil. If it smells different, and strong, it's probably transmission oil.
If it's dripping you can be pretty sure it's not grease thrown out of the u-joints right there. When were they last lubed, anyway? I do mine twice a year, just to be safe. They look like it's been a while...

A couple of common places for engine oil leaks in that area are the rear main seal, and the rear half-moon under the valve cover. The half-moon seals that the valve cover sits down on are well known leakage areas. It's easy to go to an auto parts store, pick up an extendable inspection mirror (dental mirror), so you look at the area under the rear half-moon seal. Pretty easy to see a leak there. If it's not there, chances are it's the rear main seal.
A valve cover seal set, including the half-moons, and the grommets under the nuts that hold the valve cover on, are readily available everywhere, and normally run around $17-$20.00. I use Fel-Pro, but there's a number of companies that make decent sets.

Let us know what you mech finds. It can help the next guy.
Pat☺

 

From what I can tell, it doesn't smell like much...not a bad, strong smell that you describe. Unfortunately, my auto shop (that I trust!) requires me to leave it overnight. I'm self-employed as a pet sitter, and I need my truck for my jobs. I made an appointment in 4 weeks; it's a minor leak, so I think it will be OK (I don't drive far). I may try to find a shop that's not busy and have them take a quick look.
Thank you for pointing out the U-joints -- I was told, long ago, that my U-joints cannot be lubed. Did I get bad information? I keep careful notes on everything/anything I have done, and I made a note about this in 2007. And I will definitely update what it turns out to be. Thank you!

 

I'm speaking from quite long ago experience here: You can find joints that have Zerk (gease) fittings that can be lubed with a grease gun, but neither of the last two sets I did ('65 Chevelle El Camino and '72 Plymouth Valiant) had fittings. I never did grease 'em. If you have to disassemble to grease it, might as well replace IMO. The ones I refer to both had high miles, and I knew it was time for new because I could hear that slight rythmic clicking sound as I slowly pulled into the garage. Driver-side window down cuz it was summertime.

 

PM pics to me

 

I always thought it was odd. My pickup has the non-greaseable u-joints. My 4Runners both have fully greaseable u-joints. I've replaced the pickup's u-joints 3 times now, so about every 100K miles. Never needed a u-joint for either 4Runner, but they both have a bit lower mileage than the P/U. 175,000 on the 87, 384,000 on the 99, but it's very new to me. I guess it has about the same mileage as the pickup. I lubed it's joints shortly after I got it back in March. They were pretty dry, but still in fairly good shape. Better now

Wally, I'll get some pics asap. The truck is at my mechanic getting a new interior fuseblock. Or maybe a whole new dash panel wiring harness, whichever. It caught fire last December, which is why the 99 came into our lives. Pretty sure it's the pigtail for the trailer hitch, or maybe one of the fuses shorted across to another one. No telling about that, since the plastic melted pretty well down into a lump. Anywho, I'll get you the pis ASAP. I presume inside, outside, and under, with some engine pics, yes?

Have fun, y'all!
Pat☺

 

sure. no rush, whenever you get a chance.

 

I was able to get my truck in for an inspection. The oil leak is from the manual transmission output seal. It's minor, so I will have it replaced next month since they didn't have the seal in stock (they just topped it off). I had a "new" rebuilt transmission put in 5+ years ago; I, periodically, had issues downshifting into 2nd, so 2+ years ago, I went back to the guy who did it for me (I'd been out of state, so I didn't go earlier). He test drove it (with me in the truck), and it was just fine; he said it might help if he put a lighter weight fluid in, so he drained the fluid and put in 30W.
I mentioned this to my shop today after they looked at it; he said the lighter/thinner fluid may have been more likely to seep out versus the normal heavy fluid; regardless, the seal shouldn't leak. I'm glad it's nothing major (will be about $206); they did a full inspection (brakes, etc.) and couldn't find anything wrong with my truck Yay!!!

 

One more thing, the lighter weight fluid didn't make it easier for me to get it into 2nd; I still have issues. When it decides to be stubborn, I just have to slow down to about 15 mph and double clutch (if that's the right term). Sometimes I just give up and keep it in 3rd. There are a lot of roundabouts/traffic circles here, so I deal with this quite a bit.

 

Sometimes I double-clutch going up from 4th to 5th! It makes the shift lever practically fall into place! Maybe the synchronizers in your trans are worn? Who knows what goes into a "rebuilt" or "remanufactured" item? It might be worthwhile to research the requirement for and technique for shifting a non-synchronized transmission, as well as how the synchronizing action occurs in the "synchromesh" transmission. Sometimes I drive between central Calif and Tacoma, Washington area in either my '89 pickup or '08 Corolla. Both standard trans 5 spd. It's I-5 and there are a number of long 6% down grades. If there's no traffic, I leave it in 5th and let 'er rip with throttle closed. If I run up on slow movers, I shift to 4th. I'm cheap; I don't like to use brakes unless necessary; but I do realize that you can buy a lot of brakes pads for the price of taking a look inside a transmission. That shift can be effected by just disengaging the clutch, and pulling a lever. The syncronizer has a lot of work to do there, and you should give it time to do it. To my old mind, that's almost vehicle abuse. Much better to double-clutch. Just My $0.02

I'd stick with factory recommended fluids.

Lacey...nice place! I lived in DuPont for 17 years up until a couple of years ago, working on McChord. Used to eat breakfast at Denny's next to he freeway almost every Sunday.

 

Sounds like good advice -- and you're right -- when double-clutching, it does "fall into place." I just need to be patient and more gentle. Understanding how it all works helps with that. And, yes, this is a great area! I'm from the Bay Area, but I've lived in WA a long time -- my heart is here. I bought my truck in San Jose, when I'd moved back to CA for a summer. I used to move a lot -- had a frame hitch put on my truck, and it has towed MANY 5x8 U-Haul trailers with no trouble at all! (It's a 2x4, 4 cylinder.)

 

Funny, I'm from the Bay Area as well! I really miss my home town of Woodside, but it's been ruined, like the rest of the BA. Most, if not all the redwoods I grew up walking in cut down for the rich's mansions, and homeless camps, and trash, where the rich aren't. I live in Oregon, now, but I do miss the "good ol' days". Don't we all, though.

Also, I too have a pickup. Longbed, 2X4, 22R engine, frame mounted tow hitch on it. It pulls wonderfully as well...

Copy-cat
Pat☺

 

Pictures of my 87 4Runner:















Have agreat day, all!
Pat☺