I have the clutch brake drums out to change brake bands and replace the outer seals (one side was leaking into the final drive). While I have it apart I was wondering if I should change the seals for the clutch pistons, mainly the rotary seals on the hub. I circled them in the pic I attached. I don't have all the tools I need to pull the hub so unless its needed I was planning on not doing it. But I have most of what I need so if its really necessary so I'd rather do it now while I have it apart. Also, the outer driven flanges going into the final drives both have play in them, axial and angular, but no radial play at all. The gears and bearing surfaces all look brand new so I'm not sure if its worn out or not. I'm getting progress pics, planning to post them all for anyone else doing the job. Thanks in advance
Yes, Yes, and Yes on the clutch piston seals. But make sure the bevel gear shaft bearing are good, too. When the bevel gear shaft bearings start to go, the shaft drops and the clutch piston seals get chewed up. Generally the first indication you get of bevel gear shaft bearing failure is a steering clutch actuation failure, as the piston ring fails. The flat rollers in the final drives have large clearances to be able to handle a sizeable level of metal chips coming off gear teeth. If they look good, they'll be just fine to put back. Not a lot of load on that shaft, anyway.
Ok, so its worth removing the inner flanges even if its just to check the bearings. There is no play at all with the flanges on, it feels very solid. I'll visually inspect the flat roller bearings and put new seals in, one side needs it. Do the sealing rings I underlined in the pic leak often?
No play in the bearings is good. Just make sure the rollers and races are in good condition, those taper rollers rely on preload, and as long as the preload is good, and the rollers and races show no serious nicks, dimples or rough surfaces, then you're good to go. The clutch piston ring seals are made from teflon or nylon, they're very durable. It's your call whether to replace them or not. If the cross shaft bearings are in fine shape, I'd forget about replacing the clutch piston ring seals. As to the "one side needs it", I've always found that where you have a right and left side component, if one side needs replacing, the other is not far behind it, as regards lifespan.
I will be changing both outer pinion seals, I am also changing the seals on the piston itself since they are easy to get to.
One side of the bevel gear shaft has a very small amount of side play in it, that is also the side that felt like the clutch didn't want to let go. I'll be changing the bearings and seals on both sides, since I do not want to take this apart again.
Yes, it's far better to change the bearings and seals now, rather than have the bearings collapse and possibly cause damage to the bevel gear and pinion.
Does anyone know where to get the special adapter to press the inner hubs back on? I already have the hydraulic pullers and press tooling but I don't have the adapter or spacer. I can probably make both if I can't find them.
No wonder the left steering clutch was leaking. New part ordered so I can start putting it all back together.
CAT
Cat what?
Quick question, I changed the bevel gear bearings, and the manual calls for 5-7 ft-lbs of preload, but I only have about 4 ft-lbs. But if I take out the smallest shim it goes up to about 10 ft-lbs. Is it better to be a little under or over?
I'd go a little over, it will soon bed in and loosen up. Taper rollers need that preload, if it gets sloppy the rollers start hammering on the races.
order from Cat unless you can find a shop that has one you can borrow or have a machine shop make one
The spacer is just a u shaped piece
I ended up making both, haven't used them yet but they fit.
So 10 ft-lbs is alright? I don't want to overdo it and spall the bearings
You understand that the preload is set first then the lash, but to set the preload you need lots of lash between the bevel and pinion, when you have the correct preload and it needs to be on the button really so 3 or 4 rotations of the cross shaft with a squirt of oil in the rollers to check, if you cannot reach the target by removing the thinnest shim you need to measure the shims to take out 2 and add 1 to reach the target loading, it's not hard to sort this detail, then you come to the pinion lash with powershifts having a floating pinion, direct drives have a set pinion, always check the lash on 4 points of the bevel gear as you roll it over, on the spacer to push the flanges back on I do have the correct horse shoe spacers but never use them, I prefer a thick wall tube or a pin bush that is longer than the pulling adapter when threaded on to the pinion by a 1/2".
Yes as TC said. When setting preloads on taper roller bearings a squirt of oil, and you MUST rotate the shaft half a dozen times, so the rollers ride up on the bearing cups where they will normally run. Then check what preload rotational torque you have
I think I didn't turn it enough, it was too tight so I took a shim out and it was perfect though on the bottom end of the scale, now its even lower since I turned it a few times putting bolts back in. The backlash is dead on at .015 with about +- .002 all around.
I went ahead and redid the shim set, after turning about twenty times it settled out to 85 in-lbs drag with .015 with about +- .002. I guess that's as good as it will get. Now I shouldn't have the left clutch sticking anymore, it was leaking pretty badly where the bearing was loose on that side.