76 automatic 350 tranny slipping..
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
76 automatic 350 tranny slipping..
Had the headers put on Monday...took it out for a long, hard drive yesterday...coming back home tranny began to slip...checked fluid, looked like it was a pint over....just came home for lunch today...started it, checked the tranny fluid...1/2 pint down cold....took it for a short ride, fluid looked to be 1/2 pint over again when I got back after the ride...time for a new filter and a fluid change (only, I hope) or the beginning of tragity??? 
Also, when it's cold, the fluid is good, dark red....when it hot, I can barely see it on the stick...(more )
HELP!!
Also, when it's cold, the fluid is good, dark red....when it hot, I can barely see it on the stick...(more
)HELP!!
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
You are supposed to check the fluid level after the car has been warmed to operating temperature. Add fluid and see if it still slips. If it does still slip, I would bet it needs overhauled.
Bernie
Bernie
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by BerniesVette
You are supposed to check the fluid level after the car has been warmed to operating temperature. Add fluid and see if it still slips. If it does still slip, I would bet it needs overhauled.
Bernie
Bernie
Pro
Joined: Mar 2004
Posts: 686
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From: Southeast
I'm sure a fluid and filter change won't hurt. After that, with the proper amount of fluid in it, you'll be able to see if that was the problem or not.
About the fluid getting lighter, as things heat up, the molecules spread apart. Therefore, the fluid thins as it heats which make it appear to be lighter.
About the fluid getting lighter, as things heat up, the molecules spread apart. Therefore, the fluid thins as it heats which make it appear to be lighter.
Racer
Joined: Sep 2005
Posts: 453
Likes: 1
From: Austin TX
I think for it to slip due to fluid level it would have to be more than just 1/2 pint low. As far as the level being a bit high, I've never had one slip with just a little too much fluid. Another thing that could cause it to slip would be a clogged line or lack of line pressure. As Bernie said, you check the fluid level once the transmission is up to operating temperature (with engine running) and this should be the only level that matters. Sounds like the tranny is getting ready to go.
For what it's worth, I once burned up a newly rebuilt transmission in my pickup in less than a year. I was told the problem was because the stock fluid cooler on the radiator was clogged from the original transmission going out and stuffing sludge into it. It burned up despite the fact I had a 28,000 gvrw rated cooler on it. I guess the fluid couldn't get past the radiator cooler fast enough. If you end up having the tranny rebuilt, make sure the radiator gets flushed really well. The performance shop that built my transmission told me that flushing still couldn't get all that stuff out. I ended up installing a better aluminum radiator and haven't have problems since.
GL
For what it's worth, I once burned up a newly rebuilt transmission in my pickup in less than a year. I was told the problem was because the stock fluid cooler on the radiator was clogged from the original transmission going out and stuffing sludge into it. It burned up despite the fact I had a 28,000 gvrw rated cooler on it. I guess the fluid couldn't get past the radiator cooler fast enough. If you end up having the tranny rebuilt, make sure the radiator gets flushed really well. The performance shop that built my transmission told me that flushing still couldn't get all that stuff out. I ended up installing a better aluminum radiator and haven't have problems since.
GL
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
OK, well, I had the fluid changed and the system "flushed" (he said he doesn't use solvent, pits parts), and a new filter installed...it seems to be back to normal, no slippage...BUT...he comes out with the pan, plug screwed back in, a 1/4 inch layer of fluid in it, and metal filings and chips in the fluid...I'm promptly told the tranny is shot and it'll cost $1900 to rebuild it!! 
Well, I'm not the last guy off the banana boat, I've seen mechanic friends pull this "oldest trick in the book" for many decades...a smiling fat man in a Hawaiian shirt, in up state NY telling me this?.....nah...
I figure, why repair a 30 year old tranny...can get a newer rebuilt tranny with a B&M shift kit in it for $500...if she blows, I'll pop for that and put it in, but right now, it's running strong again...
I also wonder if the new header/new larger crossover pipe install may have brought some heat closer to the cooling lines, they're about 3/4 inch close to the area where the lines are connected to the tranny, and this trans problem started immediately after the headers install...makes me wonder, ya know
Well, I'm not the last guy off the banana boat, I've seen mechanic friends pull this "oldest trick in the book" for many decades...a smiling fat man in a Hawaiian shirt, in up state NY telling me this?.....nah...
I figure, why repair a 30 year old tranny...can get a newer rebuilt tranny with a B&M shift kit in it for $500...if she blows, I'll pop for that and put it in, but right now, it's running strong again...
I also wonder if the new header/new larger crossover pipe install may have brought some heat closer to the cooling lines, they're about 3/4 inch close to the area where the lines are connected to the tranny, and this trans problem started immediately after the headers install...makes me wonder, ya know
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Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by windsoreight
$1900 for a TH350 wow. Around here it is $350-$400 if you pull it. You could shield the tranny lines.
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
I have a perfectly fine TH350 with lines, new shift cable and external cooler sitting in my garage. I installed a 5 speed manual and don't need this auto. If you are interested, PM me.
Bernie
Bernie
Heel & Toe
Joined: Nov 2005
Posts: 17
Likes: 0
I have never seen a slipping transmission really get better with just a fluid change. Once they start to slip it's only a matter of time before they are over the hill. I would line up the replacement while you have the chance.
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by 1JPC256
I have never seen a slipping transmission really get better with just a fluid change. Once they start to slip it's only a matter of time before they are over the hill. I would line up the replacement while you have the chance.