Hello everyone, I have a 1959 Chevy Apache 3100 short bed step side with original 235 cu in engine and a three speed transmission.
A long time ago, before I was born, my dad had the engine rebuilt. When the shop he took the engine too performed the work, they did some clean up work on the crank shaft. Since then I don't think the rear main seal has ever fully not leaked again. I rebuild the engine back in 2014. I did not have high hopes for it to not leak but I had to rebuild the engine because the number 5 cylinder had some coolant seeping in.
My main question is, because of the lapping performed on the crankshaft, is there any kind of main seal replacement I can get to account what I believe the shop had taken off? Or am I just kind of stuck with an ever leaking rear main seal for this engine now? Or would my only route be try and find a replacement crankshaft?
Added a picture of the truck in question with my daughter standing next to it. Picture is about 3 years old. And the truck did not look like that when I inherited it. But that's a story for another time.
Yes, there is but you'll need to remove the crankshaft to install it. Buy a Speedi-Sleeve (I believe part 99387 but you might check me on that). Install it using red Loctite, trim as needed and you will have a nice smooth surface the same size as original should be. Then discard the rope seal, buy a rubber 2 part seal and install it following directions. Actually rotate the seal about 1/8 inch or so in the groove so the ends don't line up with the block/cap seam. You should be good to go then. Alternatively you can machine the block to accept a one piece seal but that's more work and $$.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
One other suggestion but it depends on how much material was removed. You can use the rubber (some will call it neoprene, but according to Fel-Pro it was not neoprene but a proprietary rubber blend) seal and shim the back side until it fits against the crankshaft rather snugly. The negative here is you may need to remove a bit from the ends of the seal pieces if you have to shim more than about .008"...that is the most I think you can get away with.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
What Jon said about the rear main seal. You may have to check to see how much the shop ground off the crank seal surface and get a slightly smaller Speedi-Sleeve than Jon suggested so it fits tight enough.
If you go with the one piece seal, you'll need to have the block and rear main cap machined to fit the seal. I did that on my 216 (see attached pic.) The one-piece seal should take care of any cleanup grind on the seal surface of the crankshaft (unless they got real crazy.) The one-piece seal should be a National 417210 for a 3.875" shaft, 4.756" OD for 4.751" bore with 0.375" depth.
I come up with the following Speedi-Sleeve for a nominal 3.875" shaft. It's a little wide so some would have to be ground off after pressing on. Link Jon's 99387 was the correct number.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I use a piece of 3/4" thick steel plate bolted to the back of the block to mount a Van Norman cylinder boring bar for cutting the counterbore in the back of the block and the main cap. I've modified several blocks for the one piece lip seal that way. The boring bar cats' paws center up in the rear main bearing bore, and I use a square tipped sleeve cutoff tool to machine the counterbore to the right diameter, 3/8" deep. Specifications on the lip seal claim that it can handle up to a .015" +/- diameter shaft. Jerry
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