The Stovebolt Site Forums The Shop Area Engine Shop how far will the crank drop! for an oil seal?

Hi guys,

ok, trying to change the rear oil seal on 1956-7ish engine 235.

ive tryed to do it without droping the crank, but its just to tight! so have pulled the trans/split the prop and all that. of which its the 3rd time within a month after gearbox jam and grinding ring gear..new clutch ect ect

my question are how can i tell if my engine will except the neoprene seal? visually?

ive a rope one as well. i have undone the rear seal clamp and pulled the old rope seal out.

i have also undone two other claps on the crank going towards the front of the engine? is there anything else i should do as its only dropped a fraction?

Remove the rear main bearing cap and loosen the bolts on the other three caps at least 3-4 turns. The crankshaft should drop about 1/8" or so, leaving plenty or room to install either seal you choose to use. I don't think I've ever had to remove a transmission to change a rear main seal- - - -there's plenty of wobble in the input shaft to let the crank drop a little without going to that extreme. I'm partial to the rope seal- - -it seems to work better, especially if there's any roughness or a groove worn into the crankshaft hub. The only really effective way to make the back end totally dry is to machine the back of the block for a full-circle lip seal like the Ford V8 Diesels use.
Jerry

thanks Jerry. its has dropped..but still struggling to get new seal in and over the top.. have never heared of sneaky pete tooling..and cant find any in the uk..think it may be time to give this one up and order "pete" and just wait it out. the rope seal is looking a bit worse for wear the amount of times ive had a go at getting it in with wire and all.

For the rope seal, I use picture hanging wire. I tie a bit around the end and use slow steady force to pull it around. I also use a small slot screw driver to ease the leading edge into the slot.

Years ago I put a neoprene seal into a 194. The secret was to lubricate the lip and push the seal into the crank to compress it and creat clearance between the seal and the block. If the seal is forced against the parting line of the block it can slice the back off the seal.

Soak the rope seal in clean motor oil, and roll it out on a flat surface like a piece of plate glass until its diameter is reduced slightly. Use a piece of soft copper wire threaded through the end of the seal to pull it over the crankshaft, and push the other end into the slot at the same time. When the seal emerges from the end of the slot, use a packing tool like a piece of wooden dowel rod to pack it tightly into the slot. Retighten the three main bearing caps forward of the seal area and roll the crankshaft a few turns to shape the seal. Use a razor blade or a utility knife to trim the seal flush with the block, being careful not to scar the crankshaft in the process. Pack the lower rope into the cap, and trim it flush, then bolt everything together, being careful not to get seal material between the block and the cap.
Jerry

thanks alot guys..will try the above today and see how we go..lucky when i ordered bestgaskets seal..i ordered two so can have a real go few attemps...least ive painted my sump while being frustrated!

had another terrible day with the said oil seal..took all advice and also went out and got some pitcher wire.

still no joy,,wire snapped even tho heavy weight.

have a look at the photos....is there somthing im doing wrong? has the crank dropped enough? the seal is rop graffit from best gaskets and just will not want to go in?

http://i995.photobucket.com/albums/af75/hootschc/july2012135.jpg

http://i995.photobucket.com/albums/af75/hootschc/july2012134.jpg


http://i995.photobucket.com/albums/af75/hootschc/july2012133.jpg
hangman knot

http://i995.photobucket.com/albums/af75/hootschc/july2012142.jpg


http://i995.photobucket.com/albums/af75/hootschc/july2012143.jpg

http://i995.photobucket.com/albums/af75/hootschc/july2012144.jpg

http://i995.photobucket.com/albums/af75/hootschc/july2012147.jpg


i have also out in some photos of what the neoprene seal fits like? but really dont want to use it. do you think it would work and it the gap ok for this seal??

do you think a sneaky pete would do the job?


anyhelp please!

After having similar issues with my rope install I went with the neoprene seal. I'm not suggesting you should give up on the rope, but my crank surface was clean, and hasn't leaked yet! (Let me quantify by saying my 235 has only run ~40 minutes since I rebuilt it!)

Unless you saturate the seal with oil and roll it out to a considerably thinner cross-section, you will never succeed in pulling it through that groove. If you're not willing to try that approach, use the rubber seal. The small gaps behind the seal won't cause a problem as long as the lip fits the crankshaft snugly. Some people like to rotate the end of the rubber seal slightly out of alignment with the block/cap parting line, maybe 1/8" or so to minimize the possibility of getting a leak at the block/cap intersection.
Jerry

[censored] against the crank as you rotate it in.

Ha! I was going to ask you what bad word you typed Fred, but when you "Quote" someone it tells you! Looks like you forgot the space between "push" and "it"! :P (I fixed it for you in my quote!)

Thanks, I hadn't noticed it.

Hi Chaps,
well spent 4 nights on rolling forming and mainly busting knuckles and snapping wire. still no joy with the rop seal.

Monday i placed an order for special delivery of sneaky pete's ...two of them...they still have not arived..do you think they will help will pulling the rop in? anyone had good times with this tool??

ive even tryed forming the seal in the bottom shell and freezing the whole thing to keep its form but no joy..most ive made is around 1-1/2 into the hole

rubber seal is looking the way to go...

im now down to my last pair of rops so what ever i do..im running out of chances?

thankyou for all your help along the way

......

its in!!..final!

my way right or wrong...

took fly wheel off!!!!!!, dropped crank and gap at top of crank was just wide enough to fit the rope seal in.

by this i mean the seal is put in, and ontop of the crank from inside the clutch housing and pull down both sides.

using pitcher wire made two nooses and pulled each side down, tighten crank and seat seal in by turning the engine.

few... i drowned the seal in oil for an hour or so..and shaped it in the bottom shell before installing it above the crank.


thanks for everyones help...im now of out to put the rest of it together and see hows we go! god know what its done to the front oil seal but at least my clutch should be dry!