Is this too much money?

[SnS C10]

hey everyone i got a little problem with the truck. 84 silverado swb- stock 305 v8, 700r4.

Its got an oil leak. its coming from between the engine and the cover for the torque converter. i know this because i thoroughly cleaned the underside of the engine. I started it up and it started leaking on the back of the engine about where the oil filter goes. from there it goes down the TC cover and then on the exhaust. Now, its not the oil filter or lines, oil temp sending unit, or oil pan. So, that leaves the rear main seal right? I need this truck to get to work everyday so i took it to the shop and he said 350 to fix it plus an oil change, all new gaskets, seals, etc..Now im extemely mechanically inclined and would have no problem doing this, but he can have it done in one day and it would have a warranty. Does 350 sound like a good price? and is the seal just worn, or is there something else that could be wrong? thanks guys.

[N2TRUX]

If it is the rear main seal, you would need to drop the oil pan, push the old seal out and drive the new one in. Then clean the oil pan gasket and replace it along with freshh oil and filter.

It's not that hard to do if you have the right tools. If you don't want to tackle it, 350.00 aint cheap, but it's not too bad.

[ca180]

You forgot to mention removing the rear main cap


Not a bad job with the motor out of the truck. I did it before I installed my 350. Probably a pain in the arse when the motor is in. Biggest problem would probably be getting the pan bolts off, other that that I don't see a major issue.

Are you positive you don't have any oil coming down the backside of the motor?

[Square84]

ive got a small leak in back of my motor also, it would run down the torque converter guard just like yours but mine is the rear seal on the intake manifold.

[84 400]

If it is the rear main seal I did this a few months ago in the vehical.
I did mine on the 1956 willys wagon that I have in my sig. It now has a 350. Well when I installed the 350 I did not replace the rear main thinking it was fine since it did not leak... what a mistake!!!!

Anyways here is what is involved. Fist had to drop the oil pan. Then the oil pump and lower pump drive shaft come out. then the rear main cap. Then you need to remove the rear main seal or what is left of it. The bottom half is easy enough because you can just pop it out of the main cap. the upper portion sits between the crank and the engine block and is not so easy. You can utilize a set of needel nose plyers and abrass drift or a flat head screwdriver. The trick is to rotate the seal with out scratching the crank shaft surface. once you get one end of the seal rotated around you can grab it with the needle nose and work it around the crank shaft until it is all the way out. Sometimes rotating the motor can aid in this process. This by far to the most time for us. Next you want to try your best to de bur any of the seal contact areas.

The instillation can be tricky. remember your on you back and the area is quite tight so after fighting with it it can really wear at your nerves. I actually when through 2 rear main kits doing mine because when installing the upper seal I rushed and ruined it. I used the Felpro rear main seal kit and it comes with the two peace seal and the oil pump drive connector as well as a small plastic shoehorn used to aid in the instillation of the seal. Once started the upper seal slowly rotates around. It is important to go slow as any binding could ruin the seal or could indicate that some of the old seal is left in the area. Once installed you can make the ends flush or "clock" the ends where the upper and lower seals meet. Some do it the flush factory way while others say that clocking prevents leaks. I did mine flush and have no leaks. A dab of ultra black high temp RTV at the two points where the upper and lower parts of the seal meet and you are ready for re assembly. I made sure to put a good amount of assembly lube inside the rear main cap to aid in initial lubrication when starting the motor. I rotated the crank slightly to make sure it was seated properly while tightening the rear cap. The cap was torqued to 80ft as per torque specs but these could vary depending on motor. next I cleaned the oil pickup screen with brake parts cleaner and reinstalled. It is important to make sure the drive shaft for the oil pump is in and that you replace the old plastic coupler with the one found in the kit. Then torque the oil pump to the rear main cap per torque spec mine was 25foot pounds.

This is a good time too clean your oil pan of any sludge (mine had a lot) and gunk. Also I opted for a 1 piece oil pan gasket from felpro. It cost 30 dollars but is reusable and is built very well. The one piece pan gasket comes with longer mounting hex head screws for the oil pan as well as these neat little plastic clips with arrow head which hold the pan up while you put the bolts in.

Then simply refill with oil and crank the motor over a few times to build pressure in the pump before starting the motor up.

The felpro directions for the rear main seal kit and the one piece gasket are very clear and well written!!!!

Total cost:

rear main seal kit from felpro was aether $12.00 or $15.00 i can't really remember but i would suggest getting two in case you mess one up (you can always return one but it sucks to have to stop and run to the store)

One peace oil pain gasket kit from felpro $27.00

and you will need a torque wrench for the main cap bolts.

Took me about 3 hours to complete the job because I took my time and it was my first time doing a rear main in the vehicle. Don't get me wrong it is defiantly not a fun job but not as bad as i thought and my old seal was really stuck in there which was the part that took most of my time.

[ca180]

Definitely use the one piece Felpro gasket... It is reusable and will save you money in the long run. Not to mention it is probably less likely to leak.

[smashingchuck]

Originally Posted by ca180

Definitely use the one piece Felpro gasket... It is reusable and will save you money in the long run. Not to mention it is probably less likely to leak.

x2

[ont_guy_38]

Yes as mentioned in above posts make sure it isnt coming from an intake,valve cover or oil sending unit.Check that first could be a combo of all

[SnS C10]

i took a look at it and i would have to remove the exhaust as i could not get the oil pan out because they hit. Probably the starter, oil pan, main bearing cap, and maybe a few other things. Im going to double check and see if it is oil running down the block either from the intake or the oil temp sending unit. thanks for the help guys. if its the 2 pc seal, i think i will just take it in to get it done as fast as i can

[CNC]

i have a simular leak on my 71 but its the valve cover. The oil runs down the back of the motor and drips off the dust sheild.

[old Rusty C10]

these days that not too bad a price .. its alot of labor

[piecesparts]

Look real close at the rear seal on the intake, before tearing the engine apart. If nothing else get some dye and a black light to find the leak. It may save you some serious cash.

[Hoods69BadBowTie]

Originally Posted by ca180

Definitely use the one piece Felpro gasket... It is reusable and will save you money in the long run. Not to mention it is probably less likely to leak.

I totally gotta agree. I also will say take some time and double check to make sure the oil is not coming from some where else. Cause it would suck to do the rear main and it not fix the problem. Not too bad a price either I don't think.

[Slonaker]

I had a similar leak once and it turned out to be the oil pressure idiot light sending unit on the back of the intake near the distributor.

Here's Swervin's writeup on replacing the rear main seal.

http://www.73-87.com/7387garage/drivetrain/rearseal.htm

Patrick

[SnS C10]

hey everyone just an update. i got back under the truck cleaned everything spotless, started it and i found the leak. it was leaking on the sandwich adapter that the oil filter attaches to, between the adapter and the block. i took off the adapter and sure enough the o-ring was flattened and it was stiff. I replaced with a new fel-pro, and leak gone!! Cost me 10$ for the seal kit and a few bucks for a new oil filter. thanks everyones help

[Texas1971]

Shaun, did you replace the adapter and a gasket of some sort to stop your leak. I'm in the same boat you were in. It is definitely leaking from that area. Have a part #?
Thanks.

[SnS C10]

i replaced 3 o-rings in all and one gasket. 2 small o rings that goes on the actual tubing for the oil lines. 1 large oring that goes in the groove on the adapter, between the adapter and block. and the gasket, which goes between the adapter and block also. The kit was made by fel-pro and was $10, the part number is ES72671. Very easy installation, took about 45 minutes with oil change. here is a picture of the kit, the circled items are the ones i used, the others were not needed for my application. hope this helps-

[Texas1971]

Thanks a lot!!!!!!