Transmission Fluid on the Floor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bluec10 · 10-29-2003, 01:21 PM

This last spring I threw a rod in my 350. It was old and tired anyway, so I didn't shed many tears. I picked-up a used '81 350 that had just had a rering job and had a towing cam. Its a great engine, but that's not the big issue.

When I had the engine out I replaced the rear transmission seal on the TH 350. I know I should have done the front one too, but it isn't giving me grief. Recently when I was replacing the starter I had the front-end up on ramps for a couple of days. All the tranny fluid drained out the back of the transmission onto the floor.

Its a new seal and I'm really confident that it was installed correctly. Suggestions?

JimKshortstep4x4 · 10-29-2003, 01:28 PM

Just a guess but your yoke could be the culprit and the oil is coming out of the little weep hole in the yoke. If it does not leak otherwise, than I would not worry about it. When you have the tranny tipped up the pressure will cause oil to go out the splines and out the weep hole.

Jim

bluec10 · 10-30-2003, 03:52 PM

The transmission doesn't leak when its level, but if it is on any kind of an incline it does. I thought it might be a build-up of air pressure in the transmission combined with a plugged vent hole that caused it, but then it wouldn't happen if the trans is cold.

Can the weep hole be plugged?

71GMC_3/4T · 10-30-2003, 04:07 PM

You sure it came out of the tailshaft and not the speedo cable?

crazy longhorn · 10-30-2003, 08:11 PM

there is a welch plug on the back of the slipyolk that has the weep hole mentioned.....I mig welded the hole on the last leaker i had. Good luck,crazyL

bluec10 · 10-31-2003, 08:57 PM

I had an earlier encounter with the speedo cable and believe me, that is one tightly fastened speedo cable.

71GMC_3/4T · 11-01-2003, 12:41 AM

It ain't how tight you tighten it, it's how well the O-Ring seals it.
If you pull the "bullet", the gear comes out with it. The bullet has an O-ring in it that I don't think you can buy separately. You can buy a new bullet and speedo gear from a transmission supply house like Transtar (sp?). My gear shaft had a deep groove in it from many miles of use. That part doesn't leak a drop now. Now, if only I had the ambition to seal the front end of the damn thing. Aw heck, a bag of dry-sweep is still cheap...

gonebad2 · 11-01-2003, 02:58 AM

Just thought I would let you guys know....Jegs sells brand new yokes for a turbo 350 for $45.00. They are manufactured by Strange. Got mine a few weeks ago. Nice quality.

Blue Beard · 11-01-2003, 10:25 AM

You can over tighten when it comes to the o-ring and cause damage............

bluec10 · 11-03-2003, 02:42 AM

If it was the speedo gear would it make any difference if the truck was level or on an incline?

orange72350 · 11-03-2003, 02:49 AM

i just took my speedo gear outta the tranny when i too out the tranny the other day. Can i just put the gear back in and givér? i didnt see an o-ring when it came out. did i screw something up? sorry bout hijacking the thread.
dale

10-29-2003, 01:21 PM	#1
bluec10 Registered User Join Date: Apr 2002 Location: Manitoba, Canada Posts: 663	Transmission Fluid on the Floor This last spring I threw a rod in my 350. It was old and tired anyway, so I didn't shed many tears. I picked-up a used '81 350 that had just had a rering job and had a towing cam. Its a great engine, but that's not the big issue. When I had the engine out I replaced the rear transmission seal on the TH 350. I know I should have done the front one too, but it isn't giving me grief. Recently when I was replacing the starter I had the front-end up on ramps for a couple of days. All the tranny fluid drained out the back of the transmission onto the floor. Its a new seal and I'm really confident that it was installed correctly. Suggestions? __________________ Present: 2015 Tacoma. Yeah, not a GM, but I love it. 1969 GMC 32,000 - fix, drive, relax, fix... 2019 BMW R1250 GSA - Yahoooooooo 1979 Honda GL 1000 - retro touring at its best. Past: '05 Sierra 4x4 - Had 270,000 KM and running well when it was written-off by a stop sign runner. '94 F-150 from the "F word" company. I'll admit it...good truck. Sold what was left of it for $800 to a guy who came to pick it up at 11:00 PM with cash in hand. Hmm. '79 Sierra Grande (Black) organ donor - perfect rebuildable 4-bolt 350 and a good TH350. '76 Sierra Grande (Orange) - hate isn't too strong a word. Kid who bought it turned it into a hot rod. '68 C-10 R.I.P. - Dad's old truck...too far gone to resurrect. '59 C-50 - with hoist. Truck is gone, wife isn't. Nuff said.

10-30-2003, 03:52 PM	#3
bluec10 Registered User Join Date: Apr 2002 Location: Manitoba, Canada Posts: 663	The transmission doesn't leak when its level, but if it is on any kind of an incline it does. I thought it might be a build-up of air pressure in the transmission combined with a plugged vent hole that caused it, but then it wouldn't happen if the trans is cold. Can the weep hole be plugged? __________________ Present: 2015 Tacoma. Yeah, not a GM, but I love it. 1969 GMC 32,000 - fix, drive, relax, fix... 2019 BMW R1250 GSA - Yahoooooooo 1979 Honda GL 1000 - retro touring at its best. Past: '05 Sierra 4x4 - Had 270,000 KM and running well when it was written-off by a stop sign runner. '94 F-150 from the "F word" company. I'll admit it...good truck. Sold what was left of it for $800 to a guy who came to pick it up at 11:00 PM with cash in hand. Hmm. '79 Sierra Grande (Black) organ donor - perfect rebuildable 4-bolt 350 and a good TH350. '76 Sierra Grande (Orange) - hate isn't too strong a word. Kid who bought it turned it into a hot rod. '68 C-10 R.I.P. - Dad's old truck...too far gone to resurrect. '59 C-50 - with hoist. Truck is gone, wife isn't. Nuff said.

10-30-2003, 04:07 PM	#4
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	You sure it came out of the tailshaft and not the speedo cable? __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

10-30-2003, 08:11 PM	#5
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	there is a welch plug on the back of the slipyolk that has the weep hole mentioned.....I mig welded the hole on the last leaker i had. Good luck,crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

10-31-2003, 08:57 PM	#6
bluec10 Registered User Join Date: Apr 2002 Location: Manitoba, Canada Posts: 663	I had an earlier encounter with the speedo cable and believe me, that is one tightly fastened speedo cable. __________________ Present: 2015 Tacoma. Yeah, not a GM, but I love it. 1969 GMC 32,000 - fix, drive, relax, fix... 2019 BMW R1250 GSA - Yahoooooooo 1979 Honda GL 1000 - retro touring at its best. Past: '05 Sierra 4x4 - Had 270,000 KM and running well when it was written-off by a stop sign runner. '94 F-150 from the "F word" company. I'll admit it...good truck. Sold what was left of it for $800 to a guy who came to pick it up at 11:00 PM with cash in hand. Hmm. '79 Sierra Grande (Black) organ donor - perfect rebuildable 4-bolt 350 and a good TH350. '76 Sierra Grande (Orange) - hate isn't too strong a word. Kid who bought it turned it into a hot rod. '68 C-10 R.I.P. - Dad's old truck...too far gone to resurrect. '59 C-50 - with hoist. Truck is gone, wife isn't. Nuff said.

10-29-2003, 01:28 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Just a guess but your yoke could be the culprit and the oil is coming out of the little weep hole in the yoke. If it does not leak otherwise, than I would not worry about it. When you have the tranny tipped up the pressure will cause oil to go out the splines and out the weep hole. Jim

11-01-2003, 12:41 AM	#7
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	It ain't how tight you tighten it, it's how well the O-Ring seals it. If you pull the "bullet", the gear comes out with it. The bullet has an O-ring in it that I don't think you can buy separately. You can buy a new bullet and speedo gear from a transmission supply house like Transtar (sp?). My gear shaft had a deep groove in it from many miles of use. That part doesn't leak a drop now. Now, if only I had the ambition to seal the front end of the damn thing. Aw heck, a bag of dry-sweep is still cheap... __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

11-01-2003, 02:58 AM	#8
gonebad2 Merciless Butcher Join Date: Oct 2003 Location: CC Nevada Posts: 1,447	Just thought I would let you guys know....Jegs sells brand new yokes for a turbo 350 for $45.00. They are manufactured by Strange. Got mine a few weeks ago. Nice quality. __________________ Your Bought And Sold....I Got Your Soul!

11-01-2003, 10:25 AM	#9
Blue Beard Registered User Join Date: Jan 2003 Location: Washington State Posts: 8,834	You can over tighten when it comes to the o-ring and cause damage............ __________________ 1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo

11-03-2003, 02:42 AM	#10
bluec10 Registered User Join Date: Apr 2002 Location: Manitoba, Canada Posts: 663	If it was the speedo gear would it make any difference if the truck was level or on an incline? __________________ Present: 2015 Tacoma. Yeah, not a GM, but I love it. 1969 GMC 32,000 - fix, drive, relax, fix... 2019 BMW R1250 GSA - Yahoooooooo 1979 Honda GL 1000 - retro touring at its best. Past: '05 Sierra 4x4 - Had 270,000 KM and running well when it was written-off by a stop sign runner. '94 F-150 from the "F word" company. I'll admit it...good truck. Sold what was left of it for $800 to a guy who came to pick it up at 11:00 PM with cash in hand. Hmm. '79 Sierra Grande (Black) organ donor - perfect rebuildable 4-bolt 350 and a good TH350. '76 Sierra Grande (Orange) - hate isn't too strong a word. Kid who bought it turned it into a hot rod. '68 C-10 R.I.P. - Dad's old truck...too far gone to resurrect. '59 C-50 - with hoist. Truck is gone, wife isn't. Nuff said.

11-03-2003, 02:49 AM	#11
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	i just took my speedo gear outta the tranny when i too out the tranny the other day. Can i just put the gear back in and givér? i didnt see an o-ring when it came out. did i screw something up? sorry bout hijacking the thread. dale __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""



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