Yep, the truck I looked at in Hobart back when I first got the MK3 had a badly twisted chassis rail on the passenger side, just between the transfer case and winch. I'm betting that was winch-related.
I haven't posted anything in a while, as I have just been doing boring stuff like cleaning and painting.
I got new thrust bearings for the main winch worm shaft and also a pair for the chain drive box. I started putting the chain drive back together but ran into a problem.
The regular guy at the bearing place was busy so I got served by another guy. I hadn't removed the seal from the input flange on the chain case, but I had the measurements from the manual.
The seal I needed measured 2" x 3.006" x 1/2". They didn't have anything in stock and he said it was an odd size that he would have to look up and order.
A few days later he called and said it was in. I picked it up and it was a National seal, #410085. Steel cased, double lipped.
I pressed it into the housing, which didn't take much effort, and then made up a new gasket and refitted the housing and seal to the chain drive housing, with a good coat of Loctite gasket goop.
Once it was dry, I fitted a Speedi-sleeve to the drive flange, as it was pitted where the old seal had sat. I refitted the flange on the spline and then realised that when I turned it, the seal was turning in the housing.
I removed the flange and found I could turn the seal all the way around, so the housing wasn't out of shape, the seal was just too small. I was even able to work it right out of the housing by turning it while lifting.
I measured the seal and it was 3.002". I looked up the part number and it agreed.
I can't measure the inside of the housing unless I remove it from the chain drive box, which means I have to make a new gasket and clean all the goop off. I measured the old seal, which was a GACO MI 1933001/2, and although it was a bit distorted due to me levering it out, it measured 3.008".
There was a thin layer of aluminium oxide on the outside, but I never had to do more than spray the inside of the housing with degreaser and wipe it clean with a rag. When I sandblasted the outside, I protected the inside with a double layer of painters masking tape. The sand never got through.
Would getting a seal with the diameter of 3.006" really make much of a difference over the 3.0002" seal? What do you all suggest? One of the guys at work thought that the small difference in diameter probably wouldn't be enough and said to get some Loctite Bearing and Shaft Retainer. He also suggested staking the edges of the housing to stop it turning, but the housing is pretty thin cast aluminium and I am worried it might crack or distort.
The oil level in the case is well below the seal level. The seal is to keep grease in and grit out of the bearings on the input shaft. The original bearings were open. The ones I replaced them with are different. The rear one is rubber sealed and the front one, with the circlip around it, has a steel shield on the back and is open on the front. I packed the front bearing and the gap between the front and rear one with wheel bearing grease. I also filled the cavity between the front bearing and the seal, but had to scoop it all out and wipe it clean when I removed the seal again.
On another subject, I tried filing the raised ridge on the worm shaft, where the broken shear pin allowed it to spin in the sprocket until it welded itself. The file just slides over it without making a mark. The area where the seal runs is also pretty pitted, both ends of the shaft. I dug the shaft out from the MK3 winch and gave it a clean up and it is much better, so I will use it and keep the other for a spare.
Today, I took the sprocket over to an old guy who lives across from work. One of the guys at work said he used to do some lathe work in his spare time.
His wife didn't want him to talk to me, but he heard me talking about the lathe and came out to see what was going on. As soon as we started talking she gave up, threw her hands in the air and wandered off. I think this is a common act for them.
It turns out he is now over 80 and is having a real problem with macular degeneration, and is finding it almost impossible to use his lathe and other gear. He got all excited at the chance of helping me out and we ended up in his shed, which is a converted double garage. I think he must be a retired engineer. Tools everywhere, but a set place for everything. Spotless, rust-free and he knew where every single thing was.
He set the sprocket up in the lathe and got it running true. He was worried that if he took a skim off the inside that it would be loose on the shaft. He also didn't think much of the design of the sprocket, with just a lock pin that didn't even go right through. He really wanted to cut a keyway in the sprocket and shaft, but didn't have the gear anymore.
It ended up taking 3 passes with a heavy boring bar to remove enough of the ridge in the sprocket for a 1-1'2" plug to be tapped through. The ridge was really hard.
Next he wanted to do something about a better locking system, so we drilled a hole through the collar and tapped it to 3/8" BSW, as he had lock screws in that size.
As you can see, we tried drilling right through so we could have opposing lock screws. It wasn't going to happen. We rounded off 2 drill bits trying to get through that hardened skin on the far side.
He suggested I fit the sprocket on the shaft, lock it up with the original shear pin and drill a dimple in the shaft for the lock screw to seat into. I'm not sure if that will be possible as I couldn't mark the old shaft with a file.
With that all done, which took close to an hour, he wouldn't accept any payment, so I will have to find something else to give him.
There's a lot of technical know-how and skill going to be lost when he passes, and I don't think people coming up through the engineering fields these days will compare.
Jobs these days require people to narrow their fields of expertise, to be a specialist, and they miss out on a lot of skills that you pick up with the cross-training you get from having to work out how to get something done when faced with an out of the ordinary problem.
Ok, enough for now. I'll post up more once I get something worth mentioning done.
Greg.