Why do they suspect the rear seal? It's most likely the oil run off from the valve cover gaskets. If you have any basic mechanical skills, you can do the valve cover gaskets yerself. We have a thread in here that covers it as well a few on the internet, too.

Auto or manual transmission? 2WD or 4WD?

If you have an auto transmission, when was the last time you changed the ATF out? We have a thread in here that explains how to do that as well...

How good is the gear oil in the rear differential? When was the last time you checked it? Has the axle seals been leaking? Are you sure it's not the U-joints? If you have a 4WD, have you been greasing the U-joints and slip joint? If you have a 4WD, have you removed the rear drive shaft and driven it in "FWD" mode to isolate the noise from the rear? Have you cleaned out the rear differential breather valve in the 306k miles at all? Is it clogged up?

The T-100 is pretty much bullet proof unless someone jacks it up. Seems there are a lot of people/mechanics that will screw up their rear end from a bad analysis. Personally...I would keep it and fix it up. They don't make them like they used to.

If yer still wanting to sell it...maybe $2k with all the problems you have.

 

...sorry about that...it's a 2wd automatic.

I had the valve cover gaskets done before...maybe around 175k. I remember at the time my mechanic mentioned that there was a minor leak at the rear main. I've done my own oil changes for years with castrol 20w50 while substituting a quart for Lucas oil stabilizer.

As far as the ATF goes...it is pretty clean but could probably be changed at this point.

The rear differential is a different story...can't remember the last time that was serviced.

I will likely try to get her fixed and hope for the best...as a rule...how many miles can you get out of a T100 transmission?

 

...how many miles can you get out of a T100 transmission?

Well, it's certainly a heck of a lot cheaper to repair and maintain an older vehicle. I would just fix it and keep driving it if it's in good shape.

Unless your transmission is giving you problems, and since you do mostly highway miles, I see no reason to dump a truck just because it might go bad. Bam has 380K on his, and there are quite a few with similar miles and they're still going strong.

As far as the rear end...I will echo all of Bam's statements. U-joints and center carrier bearings on the driveshaft have a bad way of making people pay for "rear end" work. I'm not saying the mechanic is wrong, but some troubleshooting on your part might save you a ton of money. Grease the 10 fittings and the two slip yokes if you have the 4x4 and see if it helps, and make sure the center carrier bearing looks good and doesn't move too much in the rubber donut. I had a Supra kill a center bearing one time, and I suppose the symptoms could have been similar to a bad rear end. Keep in mind the same rear end is in the first-gen tundras as well (inc. 4x4s), and they hold up great. A 2WD T100 doing highway miles shouldn't be having any rear end issues unless something else is causing is (low/bad gear oil, water in the gear oil, etc).

As for the rear main, it may be leaking but I would fix those valve cover gaskets first (AND the rear cam seals), clean the motor and see if there are still signs of a rear main leak. But as Bam said, it's usually the valve cover gaskets that are leaking down the block. I wonder how many people have paid for a rear main before and not needed to. Also, that's the first I've ever heard of excess wear causing a new rear main to leak...that sounds fishy to me but maybe I've just never heard of it before.

As for the rear bearings...eh. They're bearings...they go bad after a while. I believe 4x4 wire may have a write up on doing the rear bearings on a 4runner or Tacoma, and I believe the T100 would be similar. If you're mechanically inclined, you can grab a Chilton/Haynes manual or FSM and do them yourself. But if it's intimidating, have the shop do it. You can do the valve covers and cam seals, and check the driveline and you may not have to spend quite so much.

I say keep the truck running...they're tough, durable, good looking trucks that are relatively easy to work on. And car payments are awful. :thumbsup:

 

Are they still gonna charge you labor if they "fix" the wrong part or only parts fees?

 

Why the heck are you running 20w-50 oil? Do you have low compression or something? Normally, 5w-30 is called for. You will get better mileage with the lower viscosity oil.

Heresy warning:

If you dont need a truck, and just drive one cause you like it, sell it and get a tiny older Tercel or something. If you are just booking down the highway with an empty truck with extra thick oil, you might prefer the thicker wallet that the car would get you.

 

Eco what others said above. I would run the recommended oil weights in the truck which is 5w-30.
Also your best phrase with any mechanic is "Show Me" There maybe oil on the rear main, but that doesn't mean that its leaking. I had oil on my transmission cooler lines. Shop told me they were leaking. I said show me. It was engine oil. Not transmission oil. You get the idea. If there is oil above the rear main, then its coming from above it. Nice thing about gravity

As SC and Bam said above its usually always cheaper to keep an older vehicle. Maybe its time to do a good tune up! Plugs, wires... I would do all fluids, coolant, brake, power steering, rear end, transmission. Also check all hoses, and belts. A good time to get under your truck and give it a great once over

 

Well...after thinking about it over the weekend...I'm going to give Sweet T some love...I ordered a FSM off of EBay tonight. Will this manual walk me through how to replace the valve cover gaskets?

At what points do I grease the rear end? Any specific grease?

I tried to drain the rear differential fluid tonight and refill...but I couldn't get the fill plug off so I abandoned that for the night. Can I use an air impact wrench on it? My plan was to get the rear differential fluid changed and the rear end greased and see if that takes care of the noise...if not then I'll attempt the bearings. Maybe at that point my FSM will be here and I can do the valve cover gaskets.

A few other questions...
How often does the timing belt and water pump have to be done?
Have I caused an issue with the 20w50 / Lucas Oil supplement? Is it ok to go back to 5w30 after using 20w50 for so long? I'd love to improve my mileage as I drive about 31k miles per year...

Sorry for all of the questions...I am more of a home improvement guy as opposed to a nuts and bolts guy...to be honest, I don't feel totally comfortable doing my vehicle maintenance but I am eager to learn and appreciate the help. :thanks:

 

Shoot some piccies and post them. You'd be amazed at what we can spot and let you know what you "might" need to address...

Valve cover gaskets can best be learned from the other threads because piccies say a thousand words. Give the search function here a try..."valve cover gaskets" should work.

I used a vice grip on my differential fill bolt and whacked it (handle...not the locker) a few times with a sledge hammer to git mine off. The socket size on the fill and drain bolt should be a 24mm...if I remember correctly. A little Teflon tape on the threads to make sure it comes off easier next time. Make sure you pull the breather valve and clean it out to make sure it's doing it's job. I ended up using synthetic gear oil in my differential and extended my breather valve. Try searching fer "extended breather valve"...

Since you have a 2WD...there isn't much you can do to yer current drive shaft unless the previous owner had the drive shaft rebuilt with greaseable U-joints as the factory OEM drive shaft is built with U-joints that aren't serviceable. Best thing you can do is pull the drive shaft and make sure the U-joints and the carrier bearing is in smooth working order. If it's not, you can contact yer local drive shaft shop and see how much it would cost to rebuild it. Make sure you mark the drive shaft mating surfaces so you can line them back up when bolting it back together.

If the drive shaft isn't the problem, it could be the differential third member and the pinion bearing. Is there any leaks from the nose of the differential? There are a few threads on the internet that should be of some assistance to you. You can also put yer rear end up on stands (use wheel chocks on the front wheels!!) and CAREFULLY run the drive line...you should be able to use a mechanic's stethoscope to see where the noise is coming from. If you find that pulling the third member or axles might be beyond yer level of expertise...you'll have to find a mechanic yer willing to trust at this point.

Fer yer motor oil...give this a read.
http://www.bobistheoilguy.com/motor-oil-101/


Good luck with yer repairs. We have a lot of other threads that will be of interest to you. Like my sway bar bushings thread, power steering rack bushings thread, oil catch jar thread...just to name a few.

 

Cant hurt to go back to the right oil. If it starts blowing smoke it isn't because you swapped oils, it cause you rings or valves have issues.

I would skip the lucas oil too, that's just making your oil thicker and draining your pocket book. These engines are pretty hard to mess up, oil wise as long as you change it regularly, but maybe your on to something with your high mileage and its running well.

The timing belt is 90K or 110K I think, but since the 3.4 engine is non interference, so if it breaks, your engine is fine, but you are not moving.

 

My threads that I've started...
http://www.toyotanation.com/forum/search.php?do=finduser&u=66630&starteronly=1

 

Well...I couldn't get the fill plug out...I tried a 24mm short socket with an impact wrench with no luck...then tried the vice grips and it wasn't going anywhere and my leverage wasn't the best lying flat on my back in the street...So off to Jiffy Lube...$108.00 later it is changed. Oh well...:facepalm:

The ride is improved but the repetitive sound is still there so it must be the bearings (hopefully)...I think the bearings take precedence over the valve cover gasket so that will be next on the list. When you guys do bearing jobs...is it common practice to go ahead and do both front and both rear at the same time?

 

There is no shame in that. Some of the best mechanics know their limit or know when to seek advice.
Just a quick thought. How sure are you that it's not your tires?

The reason I ask this is on a rav4 I had it was so loud I thought for sure it was a rear wheel bearing. I did exactly what Bam suggested. I jacked up the rear very carefully. Blocked the front tires very very good. Just be careful and safe here.

Spun the rear tires as fast as I could. It was quiet. Had the tires replaced a few thousand miles later noise disappeared! The tires were the problem.

Always always always check the easy things first. Never skip steps. If you do you will almost always skip over the problem. Ask me how I know... do a search for threads started by me. Then look for the just changing a light bulb.

Good luck and remember just ask questions. There are no dumb ones except the ones you don't ask.
Great group of guys and a few gals here! Like Bam said pics are worth 1000 words.

 

Did Jiffy Lube say anything about the gear oil condition? Snap some piccies of the fill bolt and let's see what Jiffy Lube did to the fill bolt.

Another option would've been to use a breaker bar and a floor jack on the handle to leverage that bolt, too.

Now that the fill plug has been taken off, it should be easier to take it off now and add some Teflon tape to the threads so you won't have to deal with the issue of the plug freezing back on there from all the heat cycling.

Since yer gonna be under there...you might as well pull that differential breather valve and inspect/clean it. I think it should be either a 12mm or 14mm wrench that should do the trick.

Did you ever inspect/pull the drive shaft? Don't make any assumptions until you've ruled out the simple things first.

 

I'm not 100% sure it isn't the tires...just my guess tells me it is the bearings. I have Michelin tires on Sweet T that I've always had good luck with...and I'm sure others may have had otherwise...I don't think I have a "rear-end" issue because I'm primarily on the highway and rarely hauling anything except for some landscape materials.

Jiffy Lube said nothing about the gear oil condition...should've asked...I'll take a pic of the fill bolt tonight. I did try a breaker bar last night but the socket kept slipping off...:headbang:

Bam...I'm not sure what to inspect/pull on the driveshaft. I figured I'd wait until I got the FSM...I read your link regarding the Oil Viscosity...Wow...what an eyeopener. I wish I would've paid more attention to this forum when I signed up before. I was up until 2am last night reading all of the posts you created...and SC T100 and 96Wolf...you guys have done a great service to everyone compiling this information and you guys have inspired me to treat my truck better.:thumbsup:

I want to go drain the 20w50/Lucas that I just changed 2 weeks ago and switch over to Synthetic tonight. Would you suggest a 5W-30 Synthetic for all of my highway driving?

 

Mark the flange on differential and on the drive shaft so you can mate it back up properly.
Unbolt the 4 bolts and drop the drive shaft down.
Unbolt the carrier bearing and pull the drive shaft out from the transmission.
Cycle the U-joints and see if any of the U-joints are binding. If any of them are stiff, you'll need to have the drive shaft rebuilt.
Check the carrier bearing fer play and binding. If it's bad, the drive shaft shop should be able to fix that, too.

If everything is smooth, just reverse the process to reinstall yer drive shaft. Make sure the carrier bearing is lined up before you try to tighten the bolts...which I would save the tightening fer last after you bolt in the differential side.

 

Pics - Part 1

 

Pics - Part 2

 

Looks like yer rear cam seals and valve cover gaskets are definitely leaking. Not sure if the person who changed them out put dabs of RTV at the cam corners. I still doubt the rear seal is bad...

Headlights need to be polished and sealed. Not sure if that right headlight looks right...seems a little bit set back too far. The adjuster mount could be broken.

Negative battery clamp has been tightened down too much. It's already stretched the clamp. Try replacing yer battery clamps with some brass ones.

Because of the oil leaks, yer steering rack bushings are probably toast as well. At least there is a polyurethane solution fer them now.

You should consider washing/cleaning yer converter. I have a thread listed under P0420...

 

Oh...you definitely need to pull that plastic bed liner out and clean out all the debris under there as well as doing an inspection fer corrosion/rust. If you want to keep the plastic bed liner, you can fix the bare spots up and put in a DIY bed liner coating fer cheap. Then you can put the plastic bed liner back in without too many worries.

 

You might also want to fix the ground cables on the air plenum...they look strained since they probably weren't held in place when the previous tech tightened down that bolt. They are skewed to the left.

 

You're truck looks great! For sure not ready to go to the scrap heap

 

Agreed! It looks great. And I definitely agree with Bam on the leaking valve covers and cam seals. Not a hard job with a few hand tools and some RTV and replacement parts.

Just curious, what's the white material on the tailgate, where the tailgate liner would normally go? It sort of looks like a giant cutting board.

And you have the same wheels I do...my favorites for the T100s!

 

Oh, and I have been using the the 0W-30 Mobil1 synthertic from Wal-Mart (about $25 for the big jug), as it can replace standard 5W and 10W-30 oils. I switched to that based on the Bobistheoilguy website articles. Essentially, it will ease startup wear and flow better than 5W-30 when cold, and will never get too thin as it is still a 30 weight oil. But in all honesty, I doubt there's much difference between the 5W-30 and 0W-30 synthetic...as long as it's changed when needed! :thumbsup:

 

SC is right on about the oil. I have been using synthetic for years. There are thousands of posts and discussions on that on bob is the oil guy. You can go nuts reading all those. Just make sure your head doesn't pop off

For your truck. I would get the timing belt and water pump changed. Since mine was my daily driver I had mine done at the dealership. Just shop around. You can save a few hundred bucks. I think mine was 700-800 bucks.

Crawl under your truck! Look at all the rubber parts hoses brake lines. You get the idea! You can see and learn a lot from this. Spend a good 15-30 min under there.

Next change all the fluids. Flush radiator. Check your hoses. If they are spongy replace. They are cheep and very easy. Make sure you use the right coolant. Follow the manual it should be the red dexron stuff I believe.

Have or flush yourself the brake fluid!! It absorbs water over time which is bad. It should be replaced every 2-4 years depending on where you read. Cost usually 100 bucks or so at a shop. A good shop will check your lines hoses. Check your front brakes. Pad thickness caliper and hoses. Check rear brakes! When you are jacking up the rear to check for the bearings. Have someone push the breaks and make sure they work.

Then check your bearings like states above! Take off the rear drums and spin. Make sure they are all quiet on all corners.

Spark plugs and wires. If its over 50k on the plugs they could use it. They are easy to do! Search here I'm sure Bam has a thread on how to do this. Make sure you get the right plugs! NGK only!

Also do a search for the end link and sway bar bushings. If they are original they are shot. Bam has a thread on this. It will help tighten up the front end. They are easy to install as well. And cheap.

Also your shocks! How are they? If you havent chamged them in a while they are toast. I used biliesteins. I love them. Others have kyb. Shop online search for my thread about upgrades. I found them online for a good price. Huge improvement.

I personally would run seafoam through. I have had great luck with this product. I use it in the gas tank and the intake manifold via the brake boaster vacuum line. Make sure you are ventilated as when you do the intake it will smoke. Follow the instructions in the can. Then when you go for a spirited drive watch as you will smoke out the people behind you. This is all the carbon deposits being burnt off the intake and top end of the engine.

Take pictures! And take your time! Ask questions. Glad to have you here! There are a lot of super nice guys here. Not much complaining. Just great people. You will fit right in.

Just remember all this maint is well worth it. A new truck payment is $500 bucks a month and way above. So everything you will be doing could be payed for in a matter of months comparing to a truck payment! Usually if you take care of your truck it should take care of you.

 

I prefer to use Toyota coolant only. Make sure its not the green stuff form old GM cars that so many jiffy lube type places will mix in because they dont always look in the book, and when they do, its not always right.

Never use power steering fluid in your power steering system, use transmission fluid as per your owners manual. This is another screw up that the quicky lubes will make.

I think if you had bad bearings you would hear screeching or a crunchy noise that would only last a week before they locked up. Check the temperatures of your rear axle/breaks/hub area after a long drive. If it is hot to the touch, your bearings are likely to be the culprit, if the axle is just a little warm and the temp is the same right at the wheel as it is near the center, then its very unlikely to be your bearings. If its cold outside, the axle should feel just slightly warmer than the air. This was a recommendation made by a trailer shop to double check the bearings on a trailer after repacking, so I imagine its good advice here.

I just swapped my front bearings They were barely, as in a teensy bit damaged and not preloaded correctly when someone replaced the front brakes before I bought the truck. They would still run fine for a long time, but since it was all apart, I swapped them out. The PO used aftermarket pads and discs and they were warped within 1.5 years of me owning it with no visible wear on either. I am sold on using Toyota parts for brakes, they are the only discs I can find that aren't Chinese made and I have never had any trouble (put 100K on my previous toyota pickup)

I am also a fan of Michelin tires (always get 100K miles on LTX M&S) but have elcrappos from the PO. They are bouncy wobbly POS's that I am hoping to replace soon, but they have lots of tread so I feel like I should use them up. Anyway, I could see how someone would think I had all sorts of mechanical problems if they drove my truck. Its the tires though.

As far as oil, Consumer reports ran a test with NY cab drivers testing synthetic with conventional more than 10 years back. They found that with 5K mile changes over a long period, the engines showed no wear and tear differences so long as the oil has the little logo that says "for use in gasoline engines" on the bottle. Since I read that I haven't bought into the fancy oil marketing and have found that relying on Toyota engineers works pretty well. A common theme I have seen in all Toyota discussion boards is to use Toyota OEM for parts and fluids instead of aftermarket again and again. That leads me to think, "If Toyota engineers says to use synthetic, I would" but they don't... so I don't.

I get the idea that for US car makes - aftermarket parts were often better than OEM, but its just rarely true with Toyota.

 

Try very well put! For this truck I too use toyota fluids and parts when possible. I may consider those tires as I am needing some new ones soon. My Bridgestones have 60k on them. They should last another 15 or so. Which is over the 60k mile warranty. But I'm always looking for opinions on tires

 

Hey there fellas...sorry to have been away for a while. I want to thank everybody for the feedback regarding Sweet T! A few days ago after I read the novel from Bob the Oil Guy (only made it about seven chapters in)...I figured I'd take a break and peruse the internet on a less technical subject and another hobby of mine...my Big Green Egg...While checking for a local deal on Craigslist I figured I'd search T100 for the hell of it.

...and then the earth moved...I saw my favorite truck had just listed and I had to at least look into it of course. It was 2 hours away south of Gainesville (Go Gators)...so my buddy and I left the house at 6:00 am and got up there by 9:00 with traffic. There she was...a 1996 T100 SR5 2wd auto (my exact truck) in my favorite color (charcoal grey) with no graphics...147K on the clock with a clean car fax and a mom and pop dealer that wanted it off of their lot. I hadn't considered it but they said they would take Sweet T on trade if I didn't have a buyer. So we drove back home...I stripped my truck...drove back...and drove home again...a 13 hour day but oh so worth it... :rockon:

Goodbye Sweet T...hello Earl Grey...

My wallet was 4K lighter and I didn't have Sweet T...but man I'm so excited I could jump out of my skin! I'm the third owner...first owner sold at 50K miles to a senior citizen in a large retirement village near the dealer. PERFECT! All of the service was done at Gatorland Toyota. He put 20k miles on it in the past 6 years...garage kept. Ideal...:clap:

So...now I'm searching all of the threads on my best course of action for the new truck. #1 on the list is the rear differential flush I'm bound and determined to do on my own.:lol:

My new stereo with a sirius tuner and Black powder coated aluminum low-profile tool box will be here on Monday...can't wait.

SC-I am not sure what the white material is on my tailgate...this best way to describe it would be like a cutting board with a fabricated aluminum tailgate protector. It was my favorite thing about Sweet T and I took it off for the new truck. The original owner was a cabinet maker and he added it to protect from damage while sliding cabinets in. I want to re-install it on Earl Grey but I'd love to paint it black. Do you guys think that would be a good idea?

Wolf-I've used Seafoam on my last 3 vehicles and love it...I draw it into the vacuum lines too and last time I did it I forgot to drive it after 30 minutes like I usually do. Then I left the neighborhood in the morning during the rush and I was the butt of many jokes for a while. Can that foul plugs?

Try...My last two sets of tires have been LTX MS and they seem to just never wear. Their longevity is incredible. Although I do like the look of my new tires...and the ride is good too.

Thanks again guys...bunch of pics to follow...:chug:

 

Earl Grey 1

 

Earl Grey 2