The Stovebolt Site Forums The Shop Area Engine Shop Front of 235 leaking oil

I have noticed an increase of oil under the truck during the past few months which is up front towards the front motor mount area. Yes it might just be this area of the oil pan. If not, what else might be causing the leak. Is there a front bearing seal that might be leaking?

Today I removed the entire front axle assy, which is being replaced so while all this stuff is out of the way, I thought I would replace the rear main seal and oil pan gasket. Sounds like I need to research what is causing the front leak as well. Any suggestions/comments you guys have would be ever so greatful.

Thanks
Craig

Sounds like it might be the front oil seal. Kinda hard to see behind the balancer/damper on the crank end, and the damper will have to come off to replace it. Not sure what year your 235 is, but the part number you can cross reference is "NATIONAL 6936-S" on my '61. HTH

It's a '62 235. Is this seal hard to replace? Can it be done while I have the oil pan removed?

Craig, when you pull the vibration damper, you may find a worn groove in it which allows oil to seep past the seal in the timing chain cover. This can be repaired with a "speedy sleeve" which is glued to the damper. Also plan on a new gasket for the cover, at the minimum. There is a "small parts gasket set" which has all this except the "speedy sleeve."
Good luck, had to leave my trucks behind while working out of town again. :p

There is one area that a lot of people miss and that is the fuel pump bolt washers. If you use split lock washers oil will wick out the threads and out through the split in the lock washer. It can leak more than you think. I recommend just using flat washers.

Regarding rear main seal, if my engine is a '62 will I discover a rope seal or a neoprene seal ?

Chev only used rope originly. It could have been replaced at some point with the replacement neoprene seal though.

I assume Vibration Damper and Harmonic balancer is the same? Can this be removed with engine still in truck? I looked under the front of my truck and notice that my radiator's lower tank bottom is not flat across the bottom but is raised in the middle as if I might be able to get a puller in there without removing the radiator. Do I need to note exactly the location of the balancer as related to the crank. Meaning put a mark on the balancer at say 12:00 position and be sure to put it back in same spot?

Finally, once I am ready to install the balancer back onto the crank, what holds it on?

Damper/Balancer = same thing. Yes it can be removed with engine in truck, but you'll probably have to pull the radiator at least, you may consider pulling the grille for easier access as well. I pulled all this stuff apart on Thursday in preparation for new cam and lifters, so it's still fairly fresh in my mind. Was easy for me as all the front sheet metal and radiator were removed from my truck already. The Balancer is "keyed", so it only comes off and goes back on in the same place. It is pressed back on over the key. I havent gotten this far, as my new cam isnt here til late this week, and I'll be installing a double pulley balancer in it's place to run A/C and a PS pump. But I assume it just needs to be tapped back onto the crankshaft as far as the pulley lines up with the one on the water pump above it. One other note, you may want to check carefully, or as mentioned above, replace the timing cover gasket when youre in there as well. Mine was literally "petrified" when I pulled the cover.

First, check the screws on the timing gear cover. Seal the threads with teflon or similar thread sealer.

Splashoil,
Per the attached link, is the groove that I show in the following link the one you were talking about?

http://community.webshots.com/photo/127846177/157076098HbQQsF

I did remove the radiator because it would be easier to work on the front portion of the engine without worrying about dinging up the radiator with tools and I also noticed that the lower radiator hose was coving some of the timing cover bolts.

The damper came off using my steering wheel puller with very little effort. I was almost disappointed at to the ease (kiddin').

This week I'll go out and get the necessary parts and next weekend, I'll be dropping the oil pan to replace both front and rear oil seals.

Craig, That is the usual suspect in the photo. The speedy sleeve is usually stainless designed to slip over the groove after cleaning and using the supplied adhesive. Also, as mentioned above, clean all fasteners on the timing cover real good and then dope threads prior to putting back. Also, there may be two bolts which are accessed through the pan (ie pan may need to be pulled.) I'm away from home and going on memory. You will need to get a new seal of course for the cover, think all the stuff needed is in the small parts gasket set (except the speedy sleeve.) Many vendors carry the sleeve, I know Jim Carter does, or take your dampener with you to a bearing supply and they should have one on the shelf.

The speedi-sleeve is the same as for small block chevs so most parts stores stock them.

we had oil leak on a 53 235 it was a oil plug on the front of the engine by the timing cover it had a pin hole in it and it was hard to find where the oil was coming from

As splashoil mentioned, and I neglected too, there are two bolts at the very bottom of the timing cover that need to be accessed from the backside, under the pan. You'll need to pull the pan first.

Pre 68 Dave,
can you tell me more about this sleeve solution? How thick is it and what is it made of? Do you have to machine the hub at all ?

The sleeve is a VERY thin piece of stainless steel, and goes on without any machining. I like to polish the damper snout thoroughly with a piece of emery cloth, and use a block of wood to tap the sleeve into place. Most sleeve kits come with a small tube of red LocTite to secure the sleeve into place. It will be a snug slip fit, or a very slight press fit, so some gentle persuasion with a mallet and a wood block will usually be necessary to install it. Don't overdo it on the hammering, or you'll crush the sleeve. Be very sure it starts straight, or it will buckle when it's about halfway installed.
Jerry

Maybe someone else has done this. I had a centering tool made up so that the id and od matched the crankshaft and the balancer to use when re-installing the cover so that it would fit on the proper center and not be offset. Also remember the inner lip of seal should be toward the engine! I have found them put on backwards!

I have seen the posting, more than once, about drilling the bottom two holes out and tapping them so that you can put new bolts in from the outside of the cover. My problem is that it sounds like they are saying to tap the holes in the cover but shouldn't it be tapping the holes in the front bearing cap ?

Like most of the "posts" I've done my front crank seal and used a speedy sleeve. If you have the pulley off you may as well put a sleeve on. Worth it in the long run. When you put the timing cover back on it is crucial that the pulley shaft line up perfectly with the cover/seal and in most cases it will. The hardest part (mentally) was putting the pulley back by driving it with a hammer and brass drift. After all that work I still had a leak and suspected the timing plate, which apparently does get warped or bent and leaks, albeit rarely. I thought that would be my next project but discovered that when I put the pan on I did not put enough silicone in the front half circle area and oil was leaking through a small groove. Don't skimp on the silicone. BTW I had no gaskets available at the time. Another thing I did was replace the slotted screws which hold the timing cover in place with hex head machine screws. If I ever suspected leakage from the cover it would be much easier to snug up the machine screws with a wrench than try to use a screwdriver.

Yesterday I picked up various engine seals and gaskets for my 4th of July rear seal, front seal project celebration. Also picked up the infamous speedy sleeve which was Fel-Pro's # 16202 which is to fit balancer snouts of 1.763" diameter.

Here's some shots before and after. Went on nice and firm. Used their supplied locktite. As other said, I first cleaned everything then chased the snout with some emery cloth. Applied some locktite, aligned the sleeve and then using a wooden block tapped it down until it bottomed out. Went perfectly.

http://community.webshots.com/photo/127846177/158822310ikfiZZ