Bevel gear and Collar Sleeve Welding project

[Blacklab467]

Hope this thread helps those with stripped Bevel gear input shaft / Collar sleeve splines. The goal is to weld the Collar sleeve to the Bevel gear input shaft using a technique I read in Swedespede forum. I will estimate this thread should be complete in about two weeks time and I'd like to chronicle it and include photos for others to benefit from. Although I am a licensed mechanic, I have been out of the industry for 25 years so I would rate my mechanical ability as average. Feel free to ask any questions along the way and I'll answer them as best I can.
Day 1: Removed the bevel gear from the car and reinstalled the CV shaft so I can drive it while the rest of the work is being completed. To accomplish this step, the propshaft to the rear Haldex unit needs to come off first. There's plenty of threads on this procedure within this forum, should take about 2 hours to remove the propshaft. Then you remove the passenger side CV Axle.
-There are 5-13mm bolts holding the BG onto the transmission, The second one from the top requires a open or boxed crowfoot wrench, the top one requires a universal joint right after the socket and about a 10 inch extension. Once the bolts are out, simply maneuver the BG out the bottom between the subframe, It should take less than 30 minutes to get the BG off the car. At this point, I reassembled the CV Axle and put the strut and knuckle back together so I can drive it in FWD while I await parts.

BG removed and CV axle reinstalled

Bevel3.jpg (39.1 KiB) Viewed 854 times

Stripped splines on input shaft

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It's hard to see in the picture but the spline is pretty flat where the Collar Sleeve spun on it, notable is the common "sharks tooth" wear where the collar sleeve doesn't contact the splines on the end 1-2mm, this tiny bit of the splines are intact which is how they commonly appear.

[darrylrobert]

Good luck, i made an attempt to do this drilling a large access hole in a spare Angle gear...i decided against it 1.because i dont weld 2. if the weld is crooked it will vibrate, too hot and the shaft seal will leak and cannot be replaced.

If i was to remove my Angle gear again i would use some Volvo chemical sealant around the mating surface.

[vtl]

In Eastern Europe they do a reinforced input shaft that sits tight on the collar sleeve. Of course shipping the remanufactured unit to US/CA would rob your bank account.

As an alternative: get a used AG with the healthy teeth and replace the collar sleeve every 100k km as a countermeasure. Use a fair amount of a good hydrophobic grease on the sleeve.

[Blacklab467]

Day 2 on the project. I sourced a reasonably good used collar sleeve from my local Volvo independent shop so decided not to use my brand new Volvo one. The sleeve fits somewhat snug on the Angle gear input shaft and doesn't spin like the one still on my car.
Mounted the Angle gear in the drill press and put the first 9/16 hole in the case. You'll want to measure pretty carefully before you drill, ideally the hole should line up with where the centre on the splines on the AG input shaft are for maximum strength. I've provided a ruler so you can see where the centrepoint of the hole should be

Gear1.jpg (154.37 KiB) Viewed 798 times

Next, I marked the Collar Sleeve for drilling at 120 degree intervals around the perimeter and at the depth shown in the picture. For these holes I used a pilot hole and then a 3/8 bit. The material is surprisingly soft and drills easily.

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Gear3.jpg (117 KiB) Viewed 798 times

With the Collar over the input shaft you can see that things line up fairly well.
I will take this to a machine shop/ welding shop next week and have the two parts joined permanently.
A couple essential considerations when welding:
1. A jig must be utilized such that there is zero runout on the Collar sleeve before, during, and after the welding is complete. The machine shop has a pretty good method of securing it and I will try to provide pictures of this next post. A dial indicator is used to insure the Collar sleeve is true.
2. Heat, excessive heat from welding will damage the angle gear seal and to a lesser extent, the axle seal. The axle seal can be removed for welding then reinstalled, the angle gear seal cannot! Make sure you allow the assembly to cool in between the 3 welds you will be making!
3. I'm pretty sure that balance will not be an issue but the plug welds in the evenly spaced holes should be approximately the same size and volume to minimize balance issues. The material removed and replaced are very close to the rotational centreline so any imbalance should cause minimal vibration.

Gear4.jpg (154.71 KiB) Viewed 798 times

[- Pete -]

Very good!
Another thing to consider is to weld a bung on the underside of the BG for ease of gear oil changes.
Get you a magnetic drain plug for it (same size as oil pan drain plug) so you can actually get all the debris out vs trying unsuccessfully to suck it out.

[darrylrobert]

AWD test option, please keep us updated...

AWD test Swedish Polis

awd test.jpg (42.81 KiB) Viewed 765 times

[Blacklab467]

Day 3 Update: Collar Sleeve Removal
I expected to spend the better part of Sunday getting this thing off from what I had read, I was pleasantly surprised! I jacked the car up at 12:45 and I am now documenting the procedure I used at 2:15.

1. Measure the exact distance the existing collar sleeve protrudes from the transmission case. I'm not sure how important this is for sealing purposes but I wanted to confirm that the collar sleeve bottoms out on the C-clip on the Bevel Gear prior to welding it permanently, My measurement was 1 39/64th's of an inch.

Collar 2.jpg (25.11 KiB) Viewed 742 times

2. Measure the exact distance the collar you are welding protrudes from the Bevel Gear when the collar is bottomed out on the C-clip. This measurement was 1 25/64th's on mine The total length of the collar is 3 inches........thus confirming that the collar will be in the correct position for welding when the collar is secured on the shaft with the C-clip.

Collar1.jpg (25.44 KiB) Viewed 742 times

3. With my 4 inch angle grinder, I cut a thin groove into the collar on two sides. The plan was to go in and cut a wider groove to accommodate an air hammer or possibly a puller setup. I elected at this point to give it a tap and see what I was up against. I used a 14 oz. ball pain hammer and a 10 inch masonry chisel that seemed to get reasonable purchase on the grooves I had cut. I was tapping it quite lightly because the angle that the chisel met the collar was only about 40 degrees off perpendicular to the sleeve axis and I didn't want to damage anything in the transmission. Sure enough, I saw it move after about 8 taps! I then rotated it 180 degrees and did the same. A couple more rotations and it was off.

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Did'nt need to use.jpg (33.75 KiB) Viewed 742 times

Depth of Cut.jpg (30.84 KiB) Viewed 742 times

About half a litre or so of transmission fluid came out once the collar came off. I'll measure it and ensure that the exact quantity gets put back in.

Next step is off to the welding shop tomorrow. I really wanted to have piece of mind regarding the depth of the sleeve before it gets welded on. I have been scouring the internet on this welded Collar Sleeve and it seems that many people have horror stories about leaks after its done, my suspicion is that the sleeve gets welded on haphazardly or crooked and the large lip seal in the transmission or the green o-ring doesn't seal properly afterward. If anyone has any comments on this I would like to hear from them.

[Blacklab467]

Correction, No green o-ring in the automatic transmission, that is for the manual transmission only.

[jonesg]

I wonder where the sacrificial wear will relocate to after this is welded solid.
It usually moves to the next weak link in the chain.

[SuperHerman]

jonesg - I am thinking the same. A new collar sleeve is cheaper to repair, especially if the splines are properly treated with anti-seize, than what piece will ultimately fail once welded.

I was wondering though, wouldn't it be better to pin the unit and tack weld the pin ends or use a compression pin? Drill through it, kinda like how Subaru does its CV axles.