Toyota Tundra Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·


I have read hundreds of post out there pertaining to this issue, and have had to experience it first hand. I have even read where folks have had to replace their seal/bearing several times. Toyota issued a re-designed oil seal, but the seal is only the after fact. Yes the seal is leaking, but why. The root cause to why the seal failed should be found! Oil seals have been used for many years. The oil seal in the rear axle is no different than that of a front and rear main crankshaft seal. I have a 93 Toyota 4x4 with 250,000 miles on it, and I've never replaced my crank seals, so why am I and others replacing axle seals so frequently?

First…If your seals have failed, check your differential vent before proceeding. If the vent is clogged, the pressure will find the easiest escape, which is the oil seals.

The rear bearing (SBB) sealed single ball bearing for the Tundra is manufactured with about .5mm (500µm) of axial clearance to compensate for axial run out (horizontal fluctuation). Toyota obviously had axial run out in mind when designing the rear axle. So knowing there is some axial run out, why is the retainer that the oil seal rides on so narrow (6mm). The OEM retainer that the oil seal rides on is approx. 6mm wide with a large chamfer on the end facing the differential and a small chamfer on the hub side. This retainer has to be installed in the precise location or you stand the chance of seal failure. Due to axial run out, heat expansion, etc., the seal will ride on the chamfer at times. Hence, why I’m complaining of it being to narrow!

I designed a new retainer for the seal to ride on. I do not and will not sell them however, I will share my design (free) for those of you that have the capability of having them machined & tempered through a heat treat process. The new retainer is approx. 15mm in width vs. the original at 6mm. If installed where the retainer bottoms out on top of the ABS sensor, the oil seal will ride on the center of the new retainer. Before installing the new oil seal, you must use a die grinder to open the bore of the axle housing behind the oil seal to accommodate for the extra length of the retainer. When opening the bore of the axle housing, be sure to port at the 12, 3, 6, & 9 o’clock quadrants of your bore to allow oil flow to the oil seal. This is very critical in the life of the oil seal. The oil seal must have sufficient oil flow or it will harden and become brittle.

I am in the bearing business, and specialize in differentials and rear axles. I'm not trying to sound like a know it all (KIA), I'm just expressing my experience in this business. I have seen many designs in & out that are out there, and this is not one that is bullet proof by any means. I hate to say that because I would not & do not own anything other than Toyota products. I would be a free spokesperson for them if they wanted! We all have brain farts some days, and the design engineers on this particular rear axle did that day. Through my contacts, I have been in discussion with domestic engineers (not customer service) at Toyota, and the fortunate but yet unfortunate side of things is that there is no safety issue, therefore no recall. The 07’s and up Tundras have had a similar issue, but they are from a completely different supplier than those of the Gen. 1 Tundras. I hope this information can help some of you out there that has had to do this multiple times. If you have any questions, please feel free to email me at [email protected].
 

·
Registered
Joined
·
6,781 Posts
Check that out, 75 views and no reply. Pretty informative and I like the pictures, thanks.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #3 ·
Thanks Tundrunk! I hope that this information can help some folks out. If there is anyone out there that would like the drawing to the new retainer I will be glad to email it to them. I totally new to the forum, and I joined only in hopes to lend a helping hand. Hopefully, someone out there can use this info or take it and apply it elsewhere.
 

·
Registered
Joined
·
541 Posts
Is it just my imagination or did you just turn a PITA repair job into a nearly "idiot proof" affair? Your fix eliminates any guesswork, when it comes to pressing the retainer into the proper position. I like it!
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #5 ·
Is it just my imagination or did you just turn a PITA repair job into a nearly "idiot proof" affair? Your fix eliminates any guesswork, when it comes to pressing the retainer into the proper position. I like it!
Yes, you are correct! It's a fool proof install, it provides more surface area, and it give off a fresh "new car scent" smell!!
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #6 ·
Ok everyone....Here is the drawing for the new retainer. PLEASE, if you have any questions email me at [email protected]. I will be away from my computer and I will get the message on my phone a lot faster! Product Technical drawing Diagram Cylinder Drawing
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #7 ·
Attached is the schematic of the rear axle assembly calling out the retainer in discussion. Also attaced are the instructions (from Toyota) for installing the retainer. Again, if using the OEM retainer the measurements called out in the instructions are very crucial in the life of the oil seal. The most common misconception that I have seen & heard is that when installing all of the new components, they are usually all pressed on until bottomed out. If this is done the oil seal will never even meet on the retainer that it's supposed to ride on. View attachment 48437 View attachment 48438
 

·
Registered
Joined
·
1,278 Posts
Very good info. For some of us who can make our own, 1st gen sequoia, 03-09 4runner and 05+ Tacoma uses new thicker retainers. Not sure if they will fit on tundra axles as they may have different thickness in the axles.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #9 ·
I forgot to mention something else. I found this out a little over a year & a half ago when I replaced the seal on my passenger side for the first time. I have searched for the pics but cannot find them, so I will try to give the best description as possible. Unfortunately my truck was no longer under warranty when I found this.

• Upon removing my axle for the first time on my passenger side I noticed large sharp metal burrs only about 20mm behind the oil seal.
• There is an inner metal tube that is welded inside the axle housing. This tube along with the axle housing tube provides a double wall thickness.
• The inner tube runs the length from the differential housing to about 20mm behind the oil seal.
• Obviously this inner tube goes through a deburring step in the manufacturing process.
• This particular tube had not been deburred prior to the axle being installed. Large sharp metal burrs were on the ID of this tube 360° around, and I also found the burrs attached to my drain plug on the differential.
• See the attached pics describing this.

I cannot prove that these burrs contributed to previous seal failure, but I do know that sharp metal shavings and rubber oil seal do not go well together. Knowing the tremendous amount of seal failures out there, I looked all over the web, but did not see anyone else reporting this issue.

Now, for those of you that have had seals replaced by the dealer and had no success, listen to this part. I took several photos of these burrs, and showed them to the “HEAD mechanic” at the local Toyota dealership. His exact response was “What does metal shavings have to do with your oil seal failing?” Yeah, I gave him the deer in the headlight look and simply said never mind and walked away. As Bill Engval would have said “Here’s your sign”! It just goes to show don’t always judge a book by it’s cover…. Not saying mechanics don’t know what they are doing by any means. There’s just some better than others in any field.

Just wanted to mention this to any of you DIYers so you can look for it. It will stick out like a sore thumb, no worries. If I can ever find the actual pics, I will share them.
View attachment 48462
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top