08 3.2 FWD driveshaft 172k mi: replace transmission seals too?

Post by **ogatrulle** » 20 Jan 2022, 10:59

I finally got to spend some quality time with the 08 XC90. What I previously thought to be an outer CV joint was in fact the right inner CV joint: boot has failed and there is a nice ring of grease spattered all the way around. I am hearing a clicking sound when I have the steering wheel turned all the way to the stop.

Questions:

1. The car has probably had 3000 miles on it since I first noticed this clicking. I'm assuming this means I should just replace the right driveshaft instead of re-greasing/re-booting the CV joints in the existing one. Agree/disagree?

2. Given that the car is at 172k miles, if I have the driveshaft out, how important is it to replace the transmission seal where the driveshaft fits? It looks like a bit of a hassle to get the seal out and then to reposition the new seal just right.

thanks for your insights.

Post by **ggleavitt** » 20 Jan 2022, 12:19

Dunno about the axle replacement but you're probably okay to not go in so deep to replace the transmission seal.

Pass side axle slips in through the bevel gear before making connection at the transmission. Seal is right at the transmission/angle gear sleeve interface so bevel gear will have to come off to get to it. For V8s, the subframe needs to drop to get the bevel gear out, not sure if it's the same for a 3.2.

I had my pass side CV out on both vehicles for alternator replacement and never touched the seals. I stripped the bevel gear input splines on my Sport in 2016 so those seals are newish but they're still original in the Ocean Race. Go easy putting the axle back in with a little lube at the end so you don't drag on your seal when reseating and you probably won't have any problems.

There may be an argument to removing the bevel gear, doing a new sleeve with fresh grease and seals proactively but it's a lot of work and was not something I was personally inclined to do.

Post by **ogatrulle** » 20 Jan 2022, 12:52

FWD so no bevel gear, I think.

Post by **ggleavitt** » 21 Jan 2022, 07:16

Didn't pay attention and missed that little differentiator in the post title, apologies for the churn.

Capndirk · Post by **Capndirk** » 22 Jan 2022, 10:01

I replaced both shafts on my 3.2 FWD '09. I found that the VIN specs for the right shaft and seals was erroneous at most vendors. The later shaft is bigger in diameter than the earlier, and the first one I ordered by VIN was the wrong, earlier skinny one, and ate some shipping to return it. My VIN is well above the cut-off. Pursuing the right shaft I learned that the correct heavier one is rarely stocked, and ended up getting a DSS shaft from an online retailer that was correct. Thinking to replace the seal, I ordered that by VIN and got only the small shaft one. Then, I went to the local dealer and tried to get the correct one from them. Nope, parts specs go back to the one that won't even go over the shaft, and there wasn't a listing for the outer seal at all. I re-used the original without disturbing it.
Slide it in carefully, and it should be OK.

Post by **ogatrulle** » 22 Jan 2022, 13:27

Capndirk wrote: ↑22 Jan 2022, 10:01 The later shaft is bigger in diameter than the earlier, and the first one I ordered by VIN was the wrong, earlier skinny one

Sigh. Always a part number adventure with these Volvos.

My 2010C VIDA lists 36000571 for the later chassis right driveshaft (and 36000458 for the earlier ones). Cutoff is listed as 355740 for the last "old" chassis and 355741 as the first "new" chassis. Of course Volvo also has superseding numbers for these same parts.

It lists the "old" seals as 30751873 and the "new" seals as 30751402 (same chassis number cutoffs).

Mine is about 100,000 into the "new" chassis range but I remember some funny business during the warranty period when the dealer was changing out my driveshafts for some vibration issue and they went back and forth so I'm not sure what's in there now.

Any chance you measured your driveshaft diameter and recorded the part number? I'll probably get out my calipers this afternoon and measure mine.

thanks!

Capndirk · Post by **Capndirk** » 23 Jan 2022, 20:21

I hauled out the original take-off

: sbd-shaft_2.jpg (44.3 KiB) Viewed 1085 times

The HF caliper says 43mm.
The older one may fit in the gearbox, but the outer carrier bearing won't fit in the clamp.
I bought a DSS 7843XB, and it's a great copy. 20k miles and counting,
https://www.carparts.com/axle-assembly/dss/DSS7843XB

Post by **ogatrulle** » 24 Jan 2022, 18:56

Thanks for measuring,

The DSS page you linked indicates equivalence to the later version of the driveshaft (36001220, which supersedes 36000571) as you said. The DSS price is quite attractive ($160) especially given your good experience so far.

I got sidetracked working on another vehicle and forgot to crawl under the xc90 before I showered - will measure with caliper tomorrow.

Post by **ogatrulle** » 24 Jan 2022, 19:03

ggleavitt wrote: ↑20 Jan 2022, 12:19 Dunno about the axle replacement but you're probably okay to not go in so deep to replace the transmission seal.

I think I will leave the seal as-is and make sure to oil the driveshaft (maybe with atf) in the seal region when I install it as you suggest.

Capndirk · Post by **Capndirk** » 24 Jan 2022, 22:36

I don't know how that really works in that area, but I expected all the ATF to drain out. There was none. It seems that the static level is below the transaxle output. I just slathered a nice coat of wheel bearing grease. Figured the extra body of the stuff would dam up any slight leaks. No leakage or weeping from the shaft areas after 3 years!