Transmission fluid leaks from CV axle hole.

Help, Advice, Owners' Discussion and DIY Tutorials on Volvo XC90s. The XC90 proved to be very popular, and very good for Volvo's sales numbers, since its introduction in model year 2003 (North America).
Post Reply
jaychai3
Posts: 8
Joined: Tue Aug 28, 2018 11:51 pm
Year and Model: 2006 XC90 2.5T AWD
Location: WA

Transmission fluid leaks from CV axle hole.

Post by jaychai3 »

I am working on a 2006 XC90 2.5T AWD. I am replacing the angle gear and angle gear sleeve. I am currently at the stage where the angle gear is removed and the sleeve is replaced with a new one. To test the new seals around the new sleeve, I turned on the engine. To my surprise, I see the transmission fluid leaking from the hole where the CV axle is supposed to go in, which has been removed. Is this normal? I thought that the hole was sealed because when I removed the CV axle, its spline that goes into the hole was completely dry. I looked into the hole using a mirror and I see that there is a gap deep inside where the transmission fluid can come out. My fear is that while I was removing the old sleeve, I might have damaged the transmission. In order to remove it, I inserted a 15mm socket into the hole and used a gear puller against it to remove the sleeve. I am wondering if the huge pressure that was applied on the socket pushed something inside and opened up the gap.

Looking at the end of the CV axle that goes into the hole, I am not sure if it can seal out the fluid. I know the spline fits tightly, but it is still metal-to-metal. Would the CV axle fit tight enough to seal out the transmission fluid completely?

User avatar
SuperHerman
Posts: 1674
Joined: Mon Dec 01, 2014 1:28 pm
Year and Model: 2004 & 2016 XC90
Location: Minnesota
Been thanked: 178 times

Post by SuperHerman »

Not sure if this is your issue, but I recalled something. This is from tripleedgeperformace.com (a great source for Volvo 4T65E parts, information and help)

"This is not a problem that you may even know is going on, but one that should be taken seriously and inspected. We ran into our first XC90 with this problem not too long ago and was shocked at what we saw. There is a bolt that retains the outer part of the axle / CV joint to the wheel hub. This bolt is accessable once you remove the front wheel. When you remove the bolt you experience dark colored transmission running out that seems like it never wants to stop. There is a Volvo dealer service bulletin about this problem also. The cause is a cup plug that becomes loose in the inner CV hub that goes into the drives side of the transmission- this is only a problem on the drivers side. When the plug falls out of place the transmission fluid enters the axle and cv grease mixes and goes back into the transmission. The 2003-2004 models used a hollow CV shaft that connects the inner and outer CV joints, so when you remove the retaining bolt in the wheel hub the transmission fluid will run out of this hole. The 2005 model year is said to have a solid axle so you wont have the fluid leak BUT this problem can still occur and the cv grease will mix with the transmission fluid and contaminate the transmission. Volvo does have a revised axle that addresses this problem and from what we have found is a dealer only item and in the $500+ price range. This is something that definately needs to be investigated any time a transmission is removed for repair from an XC90"

I wonder if one could insert a stud in the hole, weld it shut or epoxy it shut.

User avatar
ggleavitt
Posts: 438
Joined: Sun Jun 04, 2006 11:33 pm
Year and Model: XC90 06-VOR, 08-SPRT
Location: Seattle
Been thanked: 64 times

Post by ggleavitt »

It's possible you dislodged the inner fluid cap on the transmission side when you put the socket in the hole and pressed against it with your puller, although I'm hoping it's not your issue. Link- https://forums.swedespeed.com/showthrea ... -trans-SMH!!! has some information as well as some visuals (see subpost #19) for the area inside the transmission side of the sleeve.

Another more general link may be found here- https://forums.swedespeed.com/showthrea ... t-numbers) , posted under the S60R forum so TF-80SC I think in this example but the layout is essentially the same.

For what it's worth.
2006 V8 AWD VOR-136k
2008 V8 AWD Sport-135k

jaychai3
Posts: 8
Joined: Tue Aug 28, 2018 11:51 pm
Year and Model: 2006 XC90 2.5T AWD
Location: WA

Post by jaychai3 »

gglevitt, Thank you for posting the link that shows the picture of the hole. Based on that, I think I did push the inner cap out. What I don't understand is why the inner cap simply did not fall down when it was pushed in. When I looked into the hole with a mirror, it was still perfectly co-axial to the hole. something is holding it in place.

Assuming that it was pushed in, am I looking at a transmission overhaul? Can I use thread sealant around the CV axle to keep the tranny fluid from leaking?
On the CV axle just behind where the splines are, there is a thicker band which fits very tightly in the hole. So if I put some thread sealant around it, it may do the trick. What do you think?

User avatar
ggleavitt
Posts: 438
Joined: Sun Jun 04, 2006 11:33 pm
Year and Model: XC90 06-VOR, 08-SPRT
Location: Seattle
Been thanked: 64 times

Post by ggleavitt »

Seems like if it's the cap that's been pushed in but you're pretty sure it would not move, SuperHerman's comments about axles come to mind. It's maybe possible to put everything back and expect the inner sleeve seal to hold the leak. Now I'm talking outta my butt here but it seems like it could possibly work. Has to be someone who has made this mistake before and lived with it given that the AW55/50 is in so many other variants https://www.matthewsvolvosite.com/volvo ... ions-guide
2006 V8 AWD VOR-136k
2008 V8 AWD Sport-135k

jaychai3
Posts: 8
Joined: Tue Aug 28, 2018 11:51 pm
Year and Model: 2006 XC90 2.5T AWD
Location: WA

Post by jaychai3 »

The inner cap seems to be held in place solidly somehow - not sure by what. I think it is pushed in quite a bit though, may be a half an inch, so I am also worried if it is interfering with something behind. When I turned on the engine and put the gear in D, I see the inner cap spinning along with the axle hole, but I did not hear any abnormal noise. That makes me think I can probably live with it, but I am not sure. Is there someone familiar with the inner workings of this tranny comment on this?

As for preventing the leak, I am also thinking that I can wrap the CV axle with teflon tape so that it will fit in the hole real snug. I may also use thread sealant around the thick band I talked about. The two methods combined will probably create a really tight seal. I am not sure about the longevity though.

User avatar
ggleavitt
Posts: 438
Joined: Sun Jun 04, 2006 11:33 pm
Year and Model: XC90 06-VOR, 08-SPRT
Location: Seattle
Been thanked: 64 times

Post by ggleavitt »

My subpost #19 reference above, last link for the video, you'll see what the cap looks like from 25:00 onward. No idea if that's your problem, but at least you can see detail of that area outside of the car.

Good luck with your repair!
2006 V8 AWD VOR-136k
2008 V8 AWD Sport-135k

jaychai3
Posts: 8
Joined: Tue Aug 28, 2018 11:51 pm
Year and Model: 2006 XC90 2.5T AWD
Location: WA

Post by jaychai3 »

SuperHerman, I somehow skipped over your input. Thank you for taking your time to reply. I think what you quoted is pretty much what's happened to me except in my case it is on the passenger side and it is self-inflicted by pressing on the inner seal. By the way, my tranny is Aisin AW55-50/51SN and the CV axle is solid not hollow. The tranny did not leak before and was in good working condition.

So I am trying to recover from this blunder. I think I can seal out the fluid by using tefoln tape and/or thread sealer as I explained earlier, but I am still worried about the stability of the inner cap that's pushed in. Will it stay where it is indefinitely? After all, it will be constantly spun around as the car moves. I would like to understand how it is held in place and if it is secure and not interfering with any other parts. I imagine it will be disastrous if it falls out one day.

User avatar
ggleavitt
Posts: 438
Joined: Sun Jun 04, 2006 11:33 pm
Year and Model: XC90 06-VOR, 08-SPRT
Location: Seattle
Been thanked: 64 times

Post by ggleavitt »

One more link with visuals- viewtopic.php?f=9&t=57556
2006 V8 AWD VOR-136k
2008 V8 AWD Sport-135k

jaychai3
Posts: 8
Joined: Tue Aug 28, 2018 11:51 pm
Year and Model: 2006 XC90 2.5T AWD
Location: WA

Post by jaychai3 »

ggleavitt, you are amazing. The link you found above describes almost exactly my situation. The only difference is in his case, the inner cap was lose . Because of that he had to take apart the tranny. In my case, the inner cap is held by something. If I can convince myself that it is secure, I think I can leave it the way it is. Otherwise, I guess I am looking at taking apart the tranny like this guy had to. I think his pictures show the other side of the inner cap and it is still not clear to me how mine is not lose. Some commenters mentioned that they have not seen the inner cap on this tranny before. It makes me think perhaps there are different variations of how the inner cap is mounted.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post