NH 7220 leaking seal and gaskets

[Sven107]

I'm trying to get a few things buttoned up on my NH 7220. I've got a leaking cutterbar module on the drive end, and the seal under the hub is shot. It looks straightforward, but I'm looking for any tips on getting the old seal out and the new one in without a fight. Also, when I replace the hub, should I be using red or blue Loctite on the center bolt? And finally, when I pulled the top gear assembly off a couple of modules, there didn't seem to be a gasket. Does anyone use a gasket maker when putting them back on, or is it a metal-to-metal fit? Any advice is appreciated so I can get this thing working ASAP!

 

[HayStacker]

To swap seals, try a seal puller or gently pry the old one out. For the center bolt, use blue Loctite, it holds but lets you undo it later. Normally, the top gear seals metal-to-metal, but a little gasket maker won't hurt if leaks pop up

 

[DriedGrass88]

I'd go with a seal puller.. you can get a cheap one from an auto parts store. Once you have it out, clean everything up really well, including the bore. A little bit of grease on the new seal's lip will help it slide in without tearing. I usually use a large socket or a piece of PVC pipe that fits the outer diameter to tap it in evenly.

For the center bolt, I agree with @HayStacker to use blue Loctite. It's designed for threaded fasteners that you might need to remove later. Red is a high-strength permanent threadlocker, and you'll have a bear of a time getting that bolt out if you ever need to again.

And yes, the top gears are indeed designed to be a metal-to-metal fit. As long as the surfaces are clean and flat, you don't need a gasket or a gasket maker. Just make sure you torque the bolts correctly to prevent any leaks!!

 

[Niclas]

To put in the new seal, a seal driver or socket that's the same size as the seal's outside edge is your best bet. Cooling the seal a little bit and warming up the hub makes it easier to slide into place. Gently tap all around the seal's edge until it sits flat.