Pinion seal leaking AGAIN!

[allan5oh]

SOB, this is the third time in four years!

What the hell is wrong with this POS?

front diff of the drives, on the front. I notice that I can spin the pinion a bit, also I can slightly push it up and down.

Opinions? Thanks guys!

[allan5oh]

BTW, the vent is good. AFAIK.

[Part Time Dweller]

Make sure the yoke doesn't have a groove worn in it where the seal rides, if it does you need to replace the yoke, or, if they still make them, get a seal that comes with a sleeve that slips over the worn spot on the yoke.

Also, that up and down movement on the yoke indicates either the bearing is worn or the pre-load on the bearing isn't right. That movement also could be wearing the seal prematurely.

[allan5oh]

Make sure the yoke doesn't have a groove worn in it where the seal rides, if it does you need to replace the yoke, or, if they still make them, get a seal that comes with a sleeve that slips over the worn spot on the yoke.

Yoke was replaced last time the seal was replaced, if I'm not mistaken.

Also, that up and down movement on the yoke indicates either the bearing is worn or the pre-load on the bearing isn't right. That movement also could be wearing the seal prematurely.

That's basically the answer I was looking for.

[Kranky]

Is it a Meritor (formerly Rockwell) rear?

If so, those use a unitized pinion seal, similar to a wheel seal, where the inner diameter of the seal rotates along with the yoke, and the actual sealing occurs internally.

These have to be installed carefully, with the proper seal installation tool, or they can de damaged leading to short seal life.

Also, when reinstalling the yoke you have to be careful that it doesn't "jam" against the inner diameter of the seal as you are sliding it onto the spline, or the internal parts of the seal can be damaged, again leading to short seal life.

PTD wrote:

Also, that up and down movement on the yoke indicates either the bearing is worn or the pre-load on the bearing isn't right. That movement also could be wearing the seal prematurely.

I'll second that. If there is any such looseness, correct that before installing another new seal.

Also, even though you say a new yoke was installed, what about the splines on the input shaft?

If at one time the yoke came loose and pounded out the original seal, the splines on the input shaft could be worn just enough that the new yoke is gradually getting loose on the splines after many miles, leading to destruction of another seal.

When you check for up & down movement of the yoke, try to determine if the whole input shaft is moving up & down, or if the yoke is moving slightly on the shaft.

An easy way to check this is to look at the yoke retaining nut as you work the yoke up & down. If there is any relative motion between the yoke and retaining nut, then the yoke has come loose on the spline.

For what it's worth, I have seen instances of gear lube finding it's way along the splines and leaking out around the retaining nut due to a loose yoke also, even thogh the seal was still holding at that point.

[allan5oh]

excellent info, thank you very much!

[allan5oh]

I don't think it's the retaining nut, because the leak was behind the pinion, not the front of it.

[bob h]

the error commonly made with unitized seals is lubricating the inner diameter where it fits over the yoke... the id should be assembled dry

not sure that a speedi-sleeve CAN be installed with a unitized seal due to the tight fit over the yoke

often, the endplay will go away when the yoke is torqued

have you inspected the old seals?...... there should be evidence of why the seal failed


do not check the axle vent... replace it with the seal

[allan5oh]

do not check the axle vent... replace it with the seal

ahhh, so don't even bother thinking about not replacing it? It's just automatic for you?

Thanks guys!

Allan you are going to have to pull that front diff out and have that front Pinion shaft replaced more than likely there is a grove worn in the shaft and regardless of whatever you do it is going to leak. Best bet would be put a reman diff in it and be done with it that way you get a warrenty with it.

[Kranky]

not sure that a speedi-sleeve CAN be installed with a unitized seal due to the tight fit over the yoke

Yes Bob, you are correct.

I remember a warning in the instructions that come with the unitized seals that a speedi sleeve can not be used.

[special k]

Man Volvo's are awesome. Just bustin on ya a little bit. Good luck.

[bob h]

Allan you are going to have to pull that front diff out and have that front Pinion shaft replaced more than likely there is a grove worn in the shaft and regardless of whatever you do it is going to leak. Best bet would be put a reman diff in it and be done with it that way you get a warrenty with it.

replaceing a diff due to a leaking input seal?

a differential input/output seal does not even run on the pinion shaft... so, i doubt that the seal has worn a groove in it : (

Boh this is the 4th time it has failed in less than a year there is something else going wrong there. Seals do not keep blowing without reason. You may install one badly every know and then and that would explain one but 3 in a row sorry I am not buying that one. Look at the problems excessive endplay slop in the shaft he could have a bearing going out and that is causing a wobble and taking out the seals. Do not always look for the easy way out like a couple foreman I had as a driver they always cost the company more in the end when the trucks broke down on the side of the road and had to be towed in when they did break down. Instead of band-aid repairs diaig it right and fix it the first time that way you will not have the problem again Allen regardless of what some others may say.

Case in point in 1996 I had a rear diff go out on me boss put a reman in the truck. I told the shop there was something wrong with the reman foreman told me I was a quote DUMB ASS ****ING TRUCK DRIVER WHO DID NOT KNOW WHAT THE **** HE WAS TALKING ABOUT. end quote. By the way I am an ASE certified Master Heavy Truck Mech since 1994. I told the boss my issues and he said if if breaks on the road we will fix it and take it out of the shop FOREMANS salary. He being the shop foreman was VERY PISSED when he found out he was going to have to pay the boss back that 10K repair bill for not just the rear diff but the housing and the front one and power divider that the reman took out when the pinion shaft snapped on I-80 in Des Monies IA.

[Kranky]

Allan you are going to have to pull that front diff out and have that front Pinion shaft replaced more than likely there is a grove worn in the shaft and regardless of whatever you do it is going to leak. Best bet would be put a reman diff in it and be done with it that way you get a warrenty with it.

So, based on this logic, if he had a leaking rear main seal on the engine, which had occurred more than once, even though the engine was performing acceptably in every other way, your recommendation would be to install a complete factory reman engine costing 15 grand+.

Sorry, I just ain't agreein' with your logic.

And as Bob H said, the seal rides on the yoke. How the hell is a groove in the input shaft going to impact the seal?

Worn splines on the input shaft could cause the yoke to loosen and pound out the seal, but with a unitized seal grooves even in the yoke seal surface are far less critical than if it was a conventional type seal.

Splitshifter we are still talking the same issue with worn splines that keep pounding the seals out the one and only way to take care of the problem PROPERLY is to fix the issue causing it. As to someone suggesting I would suggest remeoving an good engine with just an oil leak and put in a REMAN GET A LIFE. Yes my maintance measures are extreme but when you pull stuff that likes to go BOOM and take out other things with it namely YOU called do not take chances.

Try having a foreman this is when I was pulling wrenches myself put a trailer that hauled 100% pure HYDROCHLORIC ACID and it had a leaking emergancy shut off valve in it. I placed it OOS because of it the foreman a total jerk forged my name and placed it back into service. Trailer comes back LOADED with 48K pounds of acid on it and the valve is dripping ACID out of it. I am the lucky bastard that get to repair it so we can pump it to another trailer. The leaking valve dropped out of the trailer and dug the boss his NEW fuel tank holes for him. Those tank holes held 2 tanks at 10K each. As for the oil leak problem I would drop the trans pull the bell housing and then oil pan and rear main seal figure out what is going out with the seal and why it keeps blowing them then fix it RIGHT the first time.

[Kranky]

figure out what is going out with the seal and why it keeps blowing them then fix it RIGHT the first time.

Exactly!

Just don't replace a lot of perfectly serviceable parts and throw a lot of unnecessary money at it to do so.

[allan5oh]

Man Volvo's are awesome. Just bustin on ya a little bit. Good luck.

Same diffs as every other truck on the road

[Maniac]

100% pure HYDROCHLORIC ACID

Sorry dude, NO SUCH thing, 25% or 50% hydro, thats all there is.Better do your homework next time.

As far as worn splines, the yoke bottoms out on the bearing when it is tourqued down, therefore even if the splines are worn it wouldn't make any difference in the seal.

Maybe its the wrong yoke.

Manic this company has made its NICHE hauling this stuff. I have seen the Manifests for it repeatily while working for them. It does exsist and has a PH of around 2 took a stainless steel tank lined with glass to haul it and special equipment to handle the crap. The trailers on this stuff have a life expectancy of only 5 years total before they are SCRAPPED due to simply losing the lining on the tank. He also pulls almost pure hydrogen Peroxide for other customers he loves the dangerous stuff and makes a fortune doing it. His drivers that pull those 2 loads make on avrage with him 90K a year NET they are paid percentage of the load and all waiting time.