Bevel gear and Collar Sleeve Welding project

[Blacklab467]

Almost a month ago I noticed that the AWD wasn't working anymore while maneuvering in an icy parking lot, also noticed a faint speed dependant noise on coasting deceleration. With all four wheels in the air, I confirmed that the propshaft rotated freely independent of the transmission.........the bevel gear output shaft was not connected to the transmission output shaft.
Yesterday I removed the bevel gear and learned that my welded collar sleeve had spun on the bevel gear input splines. In summary, the three tig welds had let go. They had held successfully for 62000 kilometres.

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Fortunately, I had a brand new collar sleeve to install in the transmission to prevent the fluid from running out, I couldn't remove the broken welded collar from the angle gear as the welding residue kept the collar from sliding off.
A trip to the auto wreckers was fruitful and a excellent non-leaking angle gear was harvested from a low mileage (232000 km) 2002 XC 70. Note that the 2002 has a different length output flange and different flange diameter so I will have to order an '03 seal before installation and swap the flanges. I plan to change the fluid and install a drain plug also before installing the new angle gear and of course the seal and transferring my old flange onto the new gear. Meanwhile while I wait for parts I will run the car in FWD, without the angle gear or propshaft for a couple weeks.
I'm a little disappointed that my original welding project wasn't a permanent fix to the problem. I find it interesting that the welds held initially, only to fail 62000 kilometres down the road. I will run with a stock angle gear/ collar sleeve setup now but will endeavour to engineer a more robust solution to this problem in the future.

[scot850]

I wonder if the 'glue' Volvo used to use on P80 car front axle splines would work? It was designed to take oust the spline 'clicking' due to variances in tolerances of the hub bearing splines and the axle itself. It would be a devil to remove if you ever had to, but might be an option if it is still sold. I'll check later as I had a bottle of it that must be 20 years old!

Neil.

[vtl]

I wonder if the 'glue' Volvo used to use on P80 car front axle splines would work? It was designed to take oust the spline 'clicking' due to variances in tolerances of the hub bearing splines and the axle itself. It would be a devil to remove if you ever had to, but might be an option if it is still sold. I'll check later as I had a bottle of it that must be 20 years old!

Neil.

This joint needs to remain flexible.

[ggleavitt]

I am in the process of having an angle gear welded with a new collar. I own a 2008 XC90 V8 Sport (TF-80SC) and have gone through 2 of these so far in 10 years of ownership (my driving style coupled with a poor design). This thread has been of immeasurable help and the machinist is pretty clear on the approach thanks to the photos. Think he's going to drill into the input shaft a little to get some weld metal in the area below the splines but this is pretty much what we'll be doing.

I have a photo link for the job (on a V8 a whole bunch of stuff comes off to get the angle gear out): https://photos.app.goo.gl/PkDiEEkyfACWfnTx5 and a thread on Swedespeed describing the initial failure in 2016 to the most recent failure in January (XC90 GEN1 forum). I'll post back once the work is done, most likely in the XC90 forum.

Again, thanks for taking the time to describe this work with the visuals.

edit- add transmission

[Blacklab467]

I am in the process of having an angle gear welded with a new collar. I own a 2008 XC90 V8 Sport (TF-80SC) and have gone through 2 of these so far in 10 years of ownership (my driving style coupled with a poor design). This thread has been of immeasurable help and the machinist is pretty clear on the approach thanks to the photos. Think he's going to drill into the input shaft a little to get some weld metal in the area below the splines but this is pretty much what we'll be doing.

I think had I drilled into the Angle gear input Splines where the holes in the collar sleeve are, the repair would have lasted indefinately, good suggestion. What prevented me from doing so was the hardness of the spline shaft and I didn't have a drill press or a good method of securing the spline while I drilled it. A machine shop should have no problem accomplishing this. Let us know how it turns out!

[vtl]

I think had I drilled into the Angle gear input Splines where the holes in the collar sleeve are, the repair would have lasted indefinately

Nope. It must have some flex. Final drive and AG input shaft are not properly coaxially aligned, collar spline takes the toll. Weld it on, and something else will have to give up.

[ggleavitt]

I'm okay seeing what goes next.

[volvolugnut]

Roll them dice...
volvolugnut

[jonesg]

I think had I drilled into the Angle gear input Splines where the holes in the collar sleeve are, the repair would have lasted indefinately

Nope. It must have some flex. Final drive and AG input shaft are not properly coaxially aligned, collar spline takes the toll. Weld it on, and something else will have to give up.

failure points should be serviceable.

[ggleavitt]

While I’m waiting for my angle gear to get reworked, I have some time to think more on my decision. I’m in a position to purchase a “new” Volvo exchange angle gear but I hesitate to do so as this is my second failure. Why me? Dunno, my mechanic packed a new sleeve full of grease when he did the first replacement in 2016.

I kept my first sleeve for a costly reminder of my driving but once I had the latest one out, I looked at them. On both sleeves, the wet transmission side is perfect. It’s the angle gear side that fails and the failure is dry rust wear over time at the spline interfaces. Dry rust wear, on a sleeve that in 2016 was well greased and had perfectly new splines on both sides. One thing I noticed, on both sleeves there are depressions in the snap ring on the angle gear side. When I look closely, the depressions appear to be made by the gear stripping and spinning on the surface with some pressure, this is where the sleeve meets the angle gear input shaft. In both cases, there’s a “smear” of metal as the input shaft spun but what’s critical to me is the fit. On both my sleeves, the clip is the limit to which the sleeve can be installed on the angle gear input shaft. I don’t see any lateral movement once it’s all put back together, it's a tight fit.

I believe that when the angle gear assembly is put on, the sleeve fits solidly against the transmission by virtue of the circlip being pressed against the angle gear input shaft as the unit gets bolted down. If this is a true, then there’s no appreciable movement of the sleeve and wear is no longer a rust exacerbated challenge.

This is what we’ll find out.



Photo of the sleeve transmission side, pretty much perfect:

Photo of the angle gear side, see spline and circlip wear:

Photo of the angle gear to transmission mounting (note rust, see how "open" the mounting interface is):

Last but not least, a poor man's diagram of the interface:

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