Transmission fluid leaks from CV axle hole.

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SuperHerman
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Re: Transmission fluid leaks from CV axle hole.

Post by SuperHerman »

It looks like we were talking two different issues. Looking at ggleavitt's last post, if this is your problem, the sound solution is to crack the case and try to reseat the cap. I don't see a real chance of getting it seated and sealed without opening the case.

I pulled out parts from an old transmission bin and found the piece mentioned in ggleavitt's post. I tried to hammer out the cup and only managed to bend and distort the cup. The cup is pressed in extremely tight and provides a 100% seal. I don't see the cup listed, hopefully yours can be reused. Most likely it comes with the piece installed.

Is this what we are talking about? First picture is from the inside of the transmission.
Pic1.jpg
Second picture is what you should see if it was not dislodged.
Pic2.jpg

jaychai3
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Year and Model: 2006 XC90 2.5T AWD
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Post by jaychai3 »

It turned out I was mistaken. The inner cap was loose after all. I could move it with a screw driver. This is bad news. I probably need to take out the transmission to deal with this problem. Or, if I attach a strong magnet at the end of the CV axle, then it will attract the loose inner cap and prevent it from moving around. But I am not sure how I can attach the magnet securely enough so that it will never fall out. If it falls out, it will probably cause more serious problems.

The tranny is 177K miles old, but there was no sign of trouble, no leakage. If I do take it out, is it worth putting it back in? I am not sure how many more miles I will get out of this one.

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Post by SuperHerman »

Is it like what I have posted in the pictures? (Note this if from an XC70 or V70 transmission which should be basically the same)

I hammered on the cap pretty good and only managed to move it a little and bend it from flat to concave. The "cap" gets inserted from the transmission side and most likely has to have the insert frozen and the gear piece really hot - it requires a good deal of force. I don't think pulling it with a magnet will do the trick. If you look at my second picture you will see it is bone dry and rusted - there was no leakage.

Here is another picture of what I hope we are talking about.
Pic3.jpg
The small piece in the front of the picture is where the cap is inserted. It resides on the bottom where the gear end is resting on the bench. We will call this part A. (It is a side view of my pictures 1 and 2 above). The top is the hole that you see when you are looking at it from the outside. The large assembly in the background we will call part B (parts diagram says it is the differential). Part A, teeth down faces up through the big geared piece and bearing (so the teeth mesh with the differential gears). I removed 12 bolts (you can see the holes) on the big differential gear and pulled up the large gear, Part A and the bearing sitting on the large gear in the picture came off the bottom of Part B. A little tapping and the bearing came off and Part A was separated from the rest of the differential.

I fear that if you leave the part in there and it dislodges it can get chewed up in the differential gears.

Were it me I would look into either rebuilding the transmission or buying a used one. I have a rebuild kit that is yours for shipping which is missing only a few items on the valve body side - the rest is intact. PM me if you are interested. I can also send the small piece in the picture if you want it (not sure if it is the same, but it shouldn't impact shipping)

jaychai3
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Post by jaychai3 »

SuperHerman,

I made my previous posting not realizing that you already posted the pictures of the parts in question. If my posting sounds disconnected from yours that is why. My apologies.

Yes, I believe what you are describing is exactly my problem. I accidentally pressed out the inner cap while I was trying to pull out the bad sleeve that goes into the angle gear using a gear puller against it.

The part A in your description, isn't if for the driver's side? The problem I have is on the passenger side where the angle gear is mated(I have AWD). In your picture, it looks like the bottom of part B is the passenger side. It probably does not matter since I am guessing the design would be the same or similar on both ends.

Looking at your pictures, I think the loose inner cap would probably stay inside the circular cavity of the bevel gear of part A shown in the first picture. The reason why I think that is because when I moved it around with a screw driver, it more or less stayed in the same spot. But I don't know what's on the other side of the inner cap. Do you think the loose inner cap can get caught in there? I thought if I put a magnet on the end of the CV axle, it will pull the loose cap away from whatever is behind it so that it does not get sucked in and keep it inside the bevel gear cavity. But it sounds like you are skeptical that it would work. Can you share your thoughts on why it would not work? Is it because you think a magnet would not be strong enough to pull the loose cap and hold it?

Would you be able to upload the picture of what part A is sitting on top of - the passenger side, if possible?

I have never replaced a transmission let along rebuild it. So I am trying desperately to find a way to solve the problem without removing it. But if that is the only option, I will probably tackle it. I already replaced most of the serviceable parts on this car, it will be a shame to stop now.

Thanks a million for your detailed and insightful postings and the pictures. It really helped me understand what I am up against.

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Post by SuperHerman »

I think we are talking the same thing and on the same side. Is the issue in this post the same issue you have? viewtopic.php?f=9&t=57556&start=20

If so I am showing what I believe are the right parts.
Pic8.jpg
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Above is a large gear assembly that attaches with 12 bolts to the differential. We will call it Part C. The bearing in Part C is pressed onto the large gear assembly.
pic4.jpg
pic4.jpg (118.06 KiB) Viewed 318 times
Above is a photo of the differential (called Part B in my prior post) with the top large geared piece removed, Part C. Looking at it closely I don't think the plug falling out will cause any issues other than no seal/leak and possible fluid cross contamination. The plug has no where to go as the two center circles touch and nothing there rotates.
Pic5.jpg
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Above is a picture of how Part A, as named in my prior post, meshes and inserts into Part B (Part C is removed so you can see how the parts mesh). Part A has the plug inserted in it that you pushed out. It is facing down.
Pic6.jpg
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Above is a picture with A, B and C joined as one, but without the 12 bolts that join them together.
Pic7.jpg
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Above is a close up of the plug/cap on Part A. You will see how it is concave rather than flat due to the pounding I gave it. It is really pressed in. I don't see how one can get the plug to be as secure as it was originally without opening the case and digging down to the part. I suppose one could seal it internally from the other side (outside of transmission) as shown in the second picture I posted - down the tube. Assuming you can pull it back tight enough it may work. Clean it very well and coat the area with plenty of RTV or maybe slather it well with JB Weld all around the cup and side walls paying attention to the joint. It shouldn't impact anything as no fluid is suppose to be there.

jaychai3
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Post by jaychai3 »

SuperHerman,

You are amazing. Thanks to your detailed pictures of the parts and explanations, I now have a very clear picture of the situation. I am convinced that I can leave the loose part alone and it will not cause any damage to the other parts of the transmission. I think you are saying that as well. I also tried to move the loose cap side ways, up and down, in and out, but it more or less stayed put in the same spot. I don't think it is possible to reattach the loose cap and seal it through the tiny hole that the CV axle goes in. I am just going to leave it alone.

So, I am going to concentrate on sealing the CV axle so that the trans fluid does not leak out. I am going to put the axle back in there and run the engine and and see how much fluid leaks out. The CV axle has a thick band just above the splines. If it leaks a lot, I am thinking of smothering the band with RTV that is made for transmissions. I am wondering if I should put some thread sealant or RTV on the splines as well. I am guessing that the CV axle will not be perfectly stationary against the hole, so I am not sure how effective the RTV will be. What I mean by that is continuous small movements will probably weaken the seal that RTV created over time. Do you have any thoughts on this?

When I posted my problem in this forum, I did not expect this level of support. I am truly grateful. As a side note, the XC90 that I am working on was in a bad shape. Almost all know weaknesses of this model was exposed - worn out angle gear and sleeve, clogged PCV system, lower control arm, water in the foot well, yaw rate sensor, steering angle sensor. I worked on most of the problems and replaced timing belt, water pump, all front suspension components, and overhauled the ignition system. I am going to repay your kindness by helping others with knowledge I gained working on this car.

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Post by SuperHerman »

Sounds like your XC90 was driven and not maintained. All of the items you list are standard maintenance items.

As to the repair, I would get a long stick and tape some cloth or paper towel on it and clean out the hole the best you can. Use some brake cleaner then final wipe with water or rubbing alcohol. Let dry. Then coat the sides of the plug where they meet the walls with RTV or JB Weld. When you are happy pull the plug back towards you as far as you can. The RTV will hopefully provide some sort of seal. I wouldn't use any other sealant on the splines in the event you have to take it apart again. RTV or JB Weld will not hurt and may do the trick.

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