Packard Forum Index » V-8 (1955-56)

Hello Everybody,
I have a leaking rear main seal on my '55 400. I want to stop the bleeding and the embarrassing wet spots in friends driveways. I read a thread about replacing the seal on an in-line 8 and did not get a "warm fuzzy" for a DIY project from that thread. I read the bulletin from Apr '55 about filing a notch in the bearing cap to stop leaks at the rear main seal. When I pull the oil pan I will look for that modification but since the leak has gotten progressively worse I don't think this is the problem. I don't have the facilities at home to pull the tranny to replace this seal. According to the Parts Cross Reference for rear main seal replacement it can be replaced in car without dropping the tranny.
If there is anyone who has replaced the rear main seal in their engine by only dropping the oil pan I would be very appreciative of any advice and techniques that will help me with this project.
Also, any recommendations on seal replacement as far as sticking with the rope seal or modernizing to the neoprene one?
Thank you for any help given.
Brian

Hi Brian: Seeing no one else chiming in on this, I'll give you my experiences. I've never changed a rear seal on a V8 with Ultramatic but I've done several on the 50-54s with Ultramatic and I did not remove the transmission. It's a fussy little job and made much easier if you have those little rear seal tool kits that used to be some common for pulling the old upper seal out and pulling the new one thru. Careful triming of the seal ends is an essential. I don't recall if the V8s have the little wooden side blocks or not, but if so they're important and so is making sure the drain or weep hole is clear. It's also mportant to use some sort of mandrel to form the seal in the lower bearing cap - see the illustrations in the shop manual. I've used the graphited cord replacement seals with complete satisfaction, seems they are usually good for about the life of the engine.

Perhaps someone else may have info on a replacement other than OEM style.

don't remember any wood pieces on mine.

i did form the seal as advised.

i used the rope type as i wasn't impressed by the fandagiling needed to make the modern one fit.

Thanks Owen and Cli55er for getting back to me. I read somewhere the name of the tool to remove the upper seal is called a "Sneaky Pete". I will see if I can find one before proceeding. I do have the rope seal. It was included in the gasket set I bought from Kanters. It comes with directions on trimming the seal, engine out. It looks like it will be a tricky job with the engine in. Thanks again. Brian

A slender corkscrew or pigtail on a longish handle may facilitate removing the old one. The "thing" for pulling the new one thru we always called the "Chinese finger toy", kind of an elongated mesh sleeve that you inserted the fresh end of the new seal into after threading it thru the channel above the crank, and as you pulled it tightened it's grip on the seal cord and pulled it thru. I'll look for a picture, but I'm sure others will have alternatives - perhaps a length of strong fishing line, or even some very fine wire that you can insert into the end of the rope like a fish hook.

PS - if you Google "chinese finger trap" you'll see something similar (not the fabric ones), this one a medical device but similar. It might have been called a "sneaky Pete".

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Look on eBay for a sneaky pete (IIRC they were also called slim jims). The sneaky pete types were used widely in dealers across all makes. Heavy engine mechanic at a Buick dealer i worked for in the 70's used them on a very regular basis on relatively new and warranty work cars, big buicks like dueces and rivieras etc. According to him they had about 80% sucess rate.

Seems to me i've seen the sneaky pete type tool on a Lisley tool display at a local auto parts store maybe 3 or 4 years ago.

I would think with as many SBC's still in service that the tool or kit is still availableand probably very inexpensive. Comes with the rope REGARDLESS of OEM type seal. I'm trying to recall from memmory. The 60's and 70's Buick V8's as well as Chevy used, as OEM, a 2 piece neoprene or some rubber type moulded seal top and bottom of the rear main. But the Sneaky Petes were used with a rope for the upper replacement.

Before attempting to replace the upper seal check the oil drain back slot in the main cap. Slot is only aboout 1/16" from oil pan seal. If slot is plugged up with sludge or RTV or oil pan seal bulging or whatever then maybe just cleaning out the slot will solve the problem.

Another rear seal remover-installer tool I remember from "back-in-the-day" is with a modified a cotter pin (split pin). Basically, take a proper sized cotter pin and make it look like a "T".

The vertical shank of the "T" fits into the drilled oiling hole in the rear main journal. The horizontal bars of the "T" fit up to the top part of the seal. The mechanic then rotates the crankshaft and the "T" shaped cotter pin catches the end of the seal and rotates it out. Reverse the procedure to install. The dimensions of the "T" are dictated by the size of the oil hole and width of the seal groove.

Like I said, this is from memory and I might have missed something important, but this is how I remember it. My computer graphics skills are narrow and shallow or else I would have provided an image. Comments anyone?

My disclaimer is I cannot recall actually doing this job, but the older I get the more I remember the things I did not do. Did I or didn't I?

Of course this method, like the "Sneaky Pete" way, is done after loosening all the main bearing caps. Probably someone here should post something about that or make a referral to the FAQ, if covered there.

I think Keith's suggestion about the rear main cap drain is something that should be looked at first. And, as long as you are there, how about that oil pump?

(o[]o)

JW

this is in the engine section of the v8 service manual, but iirc it's for removing crank bearings. Could work on the seal maybe.

Hank, maybe the cotter pin tool I am describing was meant to remove and install the upper main bearings. Like I said it was a few years ago. Good catch. Thanks.

(o[]o)