Over the past day or two this thing has began leaking oil like a sieve. I'm pretty sure it's the rear main seal, it's dripping off the trans bell housing. It's pretty bad. I left the car parked for 20mins tops, there was a fairly big oil spot when I came out. It will also leave little drips on the ground when pulling in/out of the garage. The level hasn't changed much but it sure seems to be loosing alot. Besides yanking the motor to put in a seal, are there any alternatives? I've heard of swapping in a thicker oil, does that work? Any other info/tips? Thanks guys!
Thicker oil will not change anything if it is really leaking this bad. It always drips off the lowest point. Don't assume rear main seal. Get under there, get a strong light, remove transmission inspection cover plate, follow the oil trail. It could be a leaking valve cover gasket, running down the back of the head and the block, for example. I often find the leak much higher on engines than I thought it was.
I will second what Jim just posted. Degrease and pressure wash realy good if you haven't already. Got to get the gunk off back there if it has accumulated over the years. Just keep the water away from your dizzy. Seems like all the goo and gunk accumulate around the back of of the block and down the bell housing. If it is the rear main seal- which were notorious for leaks- It is probably because they have used the older "rope" style seal. There is now a Neoprene update available for that. Just make sure you get it installed correctly as it IS directional. DONT change your oil viscosity or use additives to fix a leak. That often invites other more serious problems than a leaky seal. Erik
Not to totally contradict the last poster, but depeding on the leak, sometimes you want to clean it off last - get the srong lite, crawl underneath and look for a trail, if you do have crud on the engine it has been my experience that you can find the leak by looking for a trail that has been "washed" by the leak. If you cannot spot it, you can always clean up and then try again. :laugh: Good luck Robert
The engine is spotless, it was rebuilt/repainted about 10 years ago. It's definitely not dripping from the valve covers as I would have seen it. I'll have to investigate it furthur today, but I'm pretty sure it's the rear main seal. When did the neoprene update become avaiable? You would have thought, had it been available, the guys who rebuilt it would have used that over the "rope" style replacement. Thanks guys, like I said I'll check it out and post what I find.
Andy I switched to Castrol High Mileage oil which slowed the leak I had to a quarter size stain when shes parked.
Getting a seal done right seems to be more 'art' than 'science'-especially packing the rope 'just right'. There was a poll done on this site and the results seemed to me clear as mud. I don't think the 'seal swellers' in the high mileage oils probably help much with a rope- you've had lots of company on this one-do some site searching/reading and good luck!
The gasket kits still come with rope seals. A neoprene seal would have to be ordered separately. There's not even a neoprene seal listed for a nailhead. The ones used in nailheads are actually for other applications. Rear is a non turbo V6 and front is a 455 if I remember correctly. So unless neoprene was specifically requested by the customer or the engine builder was knowledgeable about nailheads it would be a rope seal that was put in.
I drove my 70 lark home last may after I bought it off the original owners. I drove it approximately 100 miles . When I got home it leaked about 1 quart in the driveway. I took the car to a friends house and we changed the rear main seal with a neoprene seal from postons. It wasn't to bad. I had to drop the tranny insp plate and the oil pan. Just follow the instructions because you can easily put the seal in backwards. We removed all the main caps and dropped the crank slightly to get the new seal in. Make sure you put all the main caps back in the right spots. I believe we also disconnected the flywheel so we could drop the crank slightly. Put it all back together and put in 20W and its fine with no leaks. This was done on a lift at a friends house. I wouldn't want to do this laying on the ground.
Well, I still haven't had a chance to check things out. Even though it's April we just got more snow, and are expecting even more over the weekend. Since I'll have to yank the motor for the seal, I'm just curious if any other BB Buick or GM motor/trans would drop in with out a ton of mods? I've always wanted to yank the original motor and save it. I almost put a rod the block once, I don't want to do it for real. Plus, it seems as if the Nail is very hard/expensive to get big power from. You'd have to have VERY deep pockets to get over 500hp unless you spray. Thanks for any info on the motor swap!
Andy, you don't have to pull the engine to do a rear main!!!! I have done plenty in the car. Main caps DON'T need to be loosened. As a matter of fact it's easier to install the neoprene seal than it is to remove the old rope seal. A set of my "Adjustable Roller Tip Rocker Arms" will make a world of difference by just replacing the stockers. Try them, you'll likem. Just a FYI. Tom T.
Really? I was told I'd need to yank it by 3-4 different people. I'll have to get under there and check it out. Ironically enough, every day we've had decent weather I've been putting off fixing stuff just so I could drive it. I'll have to actually get dirty this weekend... As far as swapping in another motor, it just doesn't seem probably to try and make 500+ horsepower with a Nailhead. Plus, I'll always be plagued with the Dynaflow. I need all the help I can get to get the +4500lbs boat moving.
Andy, I'm not your average hobbiest or shade tree mecanic. I do this stuff for a living & have a passion for the "Ole Nail" as evidence of designing mini-starters & "Adjustable, Variable Ratio, Roller Tip Rocker Arms". Get any repair manual that covers your year of car & read up on removing the oil pan. In '62 Buick had a mid sump pan. I KNOW the engine does not have to come out. Your also not plagued with the "DynaFlow" trans. either. You could pretty easily install a TH400 for a "NailHead" without an adapter or a variety of other trans. with an adapter. Just a little FYI.
I replaced the rear bearing oil seal with the orginal fabric style a year or so ago. I used a puller to pull it over the top of the crank. It wasn't to bad of a job and I had no experience. I would have used noeprene if I had known about it. I still get a small drop once in a while but seems to be getting better as time goes on.
Does anybody know if Bobs Automobilia has noeprene for a 364? We are going to need the Timing cover set and the rear main. I looked through thier site and can´t find anything. I found some for other years but not 1957. We have a load of parts there waiting to be shipped and thought it would be the easiest to get them there.
Now thats thinkin with yer dipstick....Jimmy !!! Love that commercial. Tom is totally correct, the rear main seal can be changed in the car, time and patience are all that's needed. Good Luck!:3gears:
I guess if I had seen the commercial I would understand what you are talking about. I have time this week and I have the engine on a stand and turned upside down so the patience part shouldnt be a problem either. If the commercial you are talking about is on you tube, please send me the link so I understand. thanks. Doc did a good write up here. (Post #4) Thanks again Doc. :TU:
