Need advice on installing crankshaft lower seal.

A

Alex Ethridge

Active Member
Briggs Engine: 09P6020076F1 (standard seven-eights-inch shaft in a 140cc OHV engine)
Briggs Seal Number: 299819S (seven-eights ID)

The last seal I installed didn't make it through the second cutting and here are all the details:
I installed the seal without removing the sump. I don't have a seal driver tool for this purpose so I:
  • buffed the debris and rust from the shaft with fine sand paper
  • wiped sandpaper residue from the shaft
  • lubricated the shaft and oil seal
  • carefully slid the oil seal to near its position
  • slid a slip-fit flat piece of metal (think washer) with a seven-eights-inch hole in it onto the shaft
  • slid a one-inch pipe over the shaft and tapped the seal into place

But here's the problem: The seal only goes as far as that flat, washer-like metal will allow. The seal that comes from the factory engine is actually driven in further which that recess somewhat protects the seal from damage from flying debris and plastic bags that might get wrapped around the shaft.

So, how can I drive the seal in further without damaging its design? Is there a special tool for installing seals while the shaft is in place? Is there maybe a shade-tree-mechanic method that will work? I thought about using a flat-end punch to carefully tap it in as I have a few of those in different sizes.

So, anyone here have any advice to give?
 
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Generic answer for most seals - use a piece of pipe. PVC will work. Steel will work. Or even just tapping with a small hammer lightly and working around and around will work too at installing seals.
 
Thanks for the reply. I thought of those things but was worried it might damage the seal as the installation is a precise process.

I'm glad to hear from someone else that maybe I should not worry so much about it. I just now ordered three genuine Briggs replacement seals (in case I screw it up, I'll have spares). They'll be here in a few days and I'll get back and let everyone know how it worked out.
 
Put in many seals without tearing the engine down. Here are some things to remember when doing this job.
1. Crankshaft must be super clean, absolutely nothing on the shaft which might cut the seal. I actually use 0000 steel wool as my last step and then use Kleenex lightly over the shaft to see if it catches on anything. Make it a shiny as possible.
2. Take a piece of a heavy Ziplock bag to wrap around the entire exposed shaft, with at least a one inch overlap. I use old microfiche cards, but most people don’t know what they are or have them.
3. Coat the plastic with lite grease, not oil. This is where an assistant comes in handy.
4. Carefully slide the seal down over the shaft by hand. Should move easily, be careful to not allow the plastic to build up under the seal.
5. Once you get the the crankcase, remove the plastic.
6. I now take a wooden dowel to tap the seal in so it is 1/32”-1/16” below the surface of the crankcase.
 
That was my concern from the beginning. I'll watch for that as best I can. I installed dozens of these back in the early 80s but have forgotten most of what I knew back then.
 
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