leaking oil, lets see how good you are - The 1947 - Present Chevrolet & GMC Truck Message Board Network

proboner · 04-12-2004, 02:55 AM

so i figured out yesterday that i have a 307 in my truck, dont know if that makes a difference. but anyways theres this small hole in my oil/tranny pan (dont know which it is) that looks like its there from the factory, or at least was drilled into it and cleaned up. well oil is dripping out of that hole pretty hardcore, im not sure if i should just plug it or what. my friend told me he thinks its where the flywheel sits, in which case i dont wanna plug it cuz itll get oil all over the clutch. any ideas where the oil is leaking from?

Z28Owner · 04-12-2004, 03:03 AM

If you mean your flywheel cover, odds are its your rear main seal of your engine, If your not sure its oil it could be tranny fluid and coming from the front seal of the tranny.

OhioDan · 04-12-2004, 04:53 AM

Sounds like rear main seal, or the torque converter seal. Either way, there's work to be done. Just my $.02 .

jku72 · 04-12-2004, 06:41 AM

If you have an auto trans, and the leaking oil is red, its trans, if its brown or black, its rear main.
If you have a standard, it could be a seal on the front of the trans, but it would be unusual. My first guess would be rear main crank seal. Unless its really pouring out, there is no need to panic. Note your oil loss in the engine, that gives you a real idea how bad the leak is.
Dont plug the hole in the cover, that would be a disaster.

67chevemall · 04-12-2004, 10:53 AM

The hole might be for the water to drip out of the flywheel cover
And the leak would be main seal!

**kwmech** · 04-12-2004, 11:24 AM

The oil feed line to the guage could also be leaking at the rear of the intake and running down the back of the block

Sweet72 · 04-12-2004, 12:05 PM

flywheel inspection cover should have a hole in it to drain. as stated before either your engine rear main is leaking or the tranny input shaft seal. You mentioned a clutch so, no torque converter. You should be able to tell whether it's engine oil or gear oil by the smell as gear oil has a kinda skunky odor.

Perchjerker · 04-12-2004, 02:49 PM

10 bucks says its the rear main.

Mike Culpepper · 04-12-2004, 03:58 PM

I vote rear main seal also, my '89 Silverado did the exact same thing and it was the seal. I drove the truck 6 months like that before I sold it , just keep adding Oil

Yes I told the new owner it had a rear main seal leak

proboner · 04-12-2004, 04:02 PM

yeah its not tranny fluid, doesnt smell ****ty enough... thanks for the input guys

04-12-2004, 02:55 AM	#1
proboner Registered User Join Date: Mar 2004 Location: mountain view, ca Posts: 28	leaking oil, lets see how good you are so i figured out yesterday that i have a 307 in my truck, dont know if that makes a difference. but anyways theres this small hole in my oil/tranny pan (dont know which it is) that looks like its there from the factory, or at least was drilled into it and cleaned up. well oil is dripping out of that hole pretty hardcore, im not sure if i should just plug it or what. my friend told me he thinks its where the flywheel sits, in which case i dont wanna plug it cuz itll get oil all over the clutch. any ideas where the oil is leaking from? __________________ 1993 ford probe gt- 15.2@90.7 http://www.cardomain.com/id/pr0b0ner 1969 chevy c10 pickup- bought for $100 at an impound lot... always wanted a 1972 blazer cst, but this will do for now!

04-12-2004, 03:03 AM	#2
Z28Owner ......................... Join Date: Nov 2001 Location: benton, ky Posts: 285	If you mean your flywheel cover, odds are its your rear main seal of your engine, If your not sure its oil it could be tranny fluid and coming from the front seal of the tranny. __________________ 1971 LWB Chevy C-10 350/350 3:42 eaton

04-12-2004, 04:53 AM	#3
OhioDan Registered User Join Date: Apr 2002 Location: New Carlisle, Ohio,USA Posts: 1,404	Sounds like rear main seal, or the torque converter seal. Either way, there's work to be done. Just my $.02 . __________________ LIFE AIN'T EASY WHEN YER FAT AND GREASY! GMC= Got More Class! 1970 GMC LWB, Fleetside, 350/4spd, Flowmaster "40's", 2002 GMC 16" Rallies, cowl hood,and added a bunch of options that weren't there when I started.

04-12-2004, 06:41 AM	#4
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	If you have an auto trans, and the leaking oil is red, its trans, if its brown or black, its rear main. If you have a standard, it could be a seal on the front of the trans, but it would be unusual. My first guess would be rear main crank seal. Unless its really pouring out, there is no need to panic. Note your oil loss in the engine, that gives you a real idea how bad the leak is. Dont plug the hole in the cover, that would be a disaster. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

04-12-2004, 10:53 AM	#5
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	The hole might be for the water to drip out of the flywheel cover And the leak would be main seal! __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD

04-12-2004, 11:24 AM	#6
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,630	The oil feed line to the guage could also be leaking at the rear of the intake and running down the back of the block

04-12-2004, 12:05 PM	#7
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	flywheel inspection cover should have a hole in it to drain. as stated before either your engine rear main is leaking or the tranny input shaft seal. You mentioned a clutch so, no torque converter. You should be able to tell whether it's engine oil or gear oil by the smell as gear oil has a kinda skunky odor. __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

04-12-2004, 02:49 PM	#8
Perchjerker Beer Power!!!!!!!!!! Join Date: Nov 2003 Location: Nacogdoches, TX Posts: 280	10 bucks says its the rear main. __________________ Rather be fishin'

04-12-2004, 03:58 PM	#9
Mike Culpepper Red Join Date: Feb 2003 Location: Llano... Texas Hill Country Posts: 448	I vote rear main seal also, my '89 Silverado did the exact same thing and it was the seal. I drove the truck 6 months like that before I sold it , just keep adding Oil Yes I told the new owner it had a rear main seal leak __________________ '72 Cheyenne LWB 350/350 "The sun don't shine on the same dog's ass all the time." - Catfish Hunter (commenting on why he was not able to pitch another perfect game).

04-12-2004, 04:02 PM	#10
proboner Registered User Join Date: Mar 2004 Location: mountain view, ca Posts: 28	yeah its not tranny fluid, doesnt smell ****ty enough... thanks for the input guys __________________ 1993 ford probe gt- 15.2@90.7 http://www.cardomain.com/id/pr0b0ner 1969 chevy c10 pickup- bought for $100 at an impound lot... always wanted a 1972 blazer cst, but this will do for now!

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