Overfilled My Transmission On My 1998 Silverado. Now It Might Be Ruine

nx02nx02 · January 27, 2008

Wasn't actually me was someone helping me fix the truck as I don't know too much about transmissions.

It's on this 1998 Silverado x-cab 4x4 Vortec 5.7 4L60E that I just bought. Well I bought it with a bad tranny in it so we bought a good used one from a auto wrecking yard and my friend put it in. I think he overfilled the tranny fluid by a lot and it has leaked probably at least 4 quarts or so by now. I don't know for sure where the fluid is leaking from though it is just coming from everywhere.

The truck has been driven about 20 or 30 miles since the new transmission has been in.

I need a bit of advice, what I am wondering about it is did the seals in the transmission blow from overfilling?

The transmission slips and is alot rougher, more vibration when driving down the road then what the old transmission was doing. The new one has like alot of vibration to it. Kind of hard to explain. When you accelerate the powertrain feels alot rougher, more vibration and just isn't smooth anymore like it was when the old transmission was when I first bought the truck a week or so ago. (The old transmission worked, just didn't have reverse).

Another thing now the 4 wheel drive seems to not work too good either. It doesn't engage and disengage 4 wheel drive smoothly like it did when I first got it just a week ago. I know you need to take off the transfer case in order to replace a transmission so did they not connect it back together right? They told me some fluid leaked out of the transfer case and they didn't refill it.

I also noticed that my friend was testing out the 4 wheel drive after he put the new transmission in and he was trying to engage it while the truck was in park? He didn't put it in neutral he did it in park And grinding the gears like crazy. He did it a couple times. Could this hurt the truck doing this? the 4 wheel drive doesn't seem to work right anymore. Now it's hard to get it to engage and disengage.

So heres all the stuff wrong. Hopefully someone can tell me what's wrong and what would be the easiest, cheapest way to fix it.

1. Truck is leaking tons of transmission fluid.

2. Was overfilled by alot

3. Transmission is now slipping

4. Rough vibration while accelerating coming from powertrain.

5. 4 wheel drive no longer engages and disengages smoothly.

Can someone tell my what all these problems are caused by.

Think I should take it to the dealer and have a tranny service done to get the fluid right? Did the seals blow?

Thank you for any help.

Mr. Smith · January 27, 2008

1. Truck is leaking tons of transmission fluid.

2. Was overfilled by alot

3. Transmission is now slipping

4. Rough vibration while accelerating coming from powertrain.

5. 4 wheel drive no longer engages and disengages smoothly.

----------------

Drain transmission to the proper level. If it was overfilled to the extreme you may have trashed many internal seals. and a rebuild is in order. Slippis is very bad and it is unlikely to stop with the lowering of the fluid level.

Take the rest step by step but the first four are IMO transmission related.

nx02nx02 · January 27, 2008

Just checked the truck and now the reverse doesn't work. Do you think overfilling it took out the reverse as well?

nx02nx02 · January 27, 2008

I just checked the transmission fluid and it is still over full and bubbly. Does the bubbles have anything to do with it?

jnpaddison · January 27, 2008

you are 'frothing' the fluid - your clutches may be burnt

drain the fluid to correct level and cross your fingers you dont need a rebuild

nx02nx02 · January 27, 2008

what's the easiest way to drain some out?

Although I have a bad feeling it's too late.

jnpaddison · January 27, 2008

drop the pan,, replace filter and fluids correctly ...

is the fluild - apart from bubbly - is it still pink or tinged black - any smell ??

nx02nx02 · January 27, 2008

It's still the red pink color and doesn't smell burnt or anything. But the reverse has worked for a few hours (while it was over full) Then I checked it a while ago and the reverse barely works. slips like crazy. high rpms barely moves the truck in reverse. it slips in drive too.

sillyazz · January 27, 2008

Wasn't actually me was someone helping me fix the truck as I don't know too much about transmissions.

It's on this 1998 Silverado x-cab 4x4 Vortec 5.7 4L60E that I just bought. Well I bought it with a bad tranny in it so we bought a good used one from a auto wrecking yard and my friend put it in. I think he overfilled the tranny fluid by a lot and it has leaked probably at least 4 quarts or so by now. I don't know for sure where the fluid is leaking from though it is just coming from everywhere.

The truck has been driven about 20 or 30 miles since the new transmission has been in.

I need a bit of advice, what I am wondering about it is did the seals in the transmission blow from overfilling?

The transmission slips and is alot rougher, more vibration when driving down the road then what the old transmission was doing. The new one has like alot of vibration to it. Kind of hard to explain. When you accelerate the powertrain feels alot rougher, more vibration and just isn't smooth anymore like it was when the old transmission was when I first bought the truck a week or so ago. (The old transmission worked, just didn't have reverse).

Another thing now the 4 wheel drive seems to not work too good either. It doesn't engage and disengage 4 wheel drive smoothly like it did when I first got it just a week ago. I know you need to take off the transfer case in order to replace a transmission so did they not connect it back together right? They told me some fluid leaked out of the transfer case and they didn't refill it.

I also noticed that my friend was testing out the 4 wheel drive after he put the new transmission in and he was trying to engage it while the truck was in park? He didn't put it in neutral he did it in park And grinding the gears like crazy. He did it a couple times. Could this hurt the truck doing this? the 4 wheel drive doesn't seem to work right anymore. Now it's hard to get it to engage and disengage.

So heres all the stuff wrong. Hopefully someone can tell me what's wrong and what would be the easiest, cheapest way to fix it.

1. Truck is leaking tons of transmission fluid.

2. Was overfilled by alot

3. Transmission is now slipping

4. Rough vibration while accelerating coming from powertrain.

5. 4 wheel drive no longer engages and disengages smoothly.

Can someone tell my what all these problems are caused by.

Think I should take it to the dealer and have a tranny service done to get the fluid right? Did the seals blow?

Thank you for any help.

I say the transmission you bought from the wrecking yard was a bigger POS than the one you already had in the truck. Just because the wrecking yard says its good its still USED. Sounds like it time to take it in for an overhaul.

BowTieDude · January 28, 2008

I'd try taking the original tranny that was in the truck to a good trans shop and have it rebuilt and installed by them. Sounds like it has less problems than the replacement. Then, take the one from the junkyard back if they gave you any kind of warranty. Although you're probably out the money on it. I try to stay away from junkyards if possible just for this reason. Even if they give a warranty they can always say "you" caused it to fail (whether you did or not) then flake on the warranty.

nx02nx02 · January 28, 2008

I am going to try a tranny service today. New gasket, filter and fluid and hope it helps.

I have a couple questions about the service and need a little help.

I think I can do it. I have never actually done it before but I understand mostly how it's done.

I need help on 2 things though.

First, believe it or not, me and my friend dropped the pan last night and there is no filter there.

The wrecking yard took the filter and gasket off and the people that installed the transmission didn't actually check to see if the filter or gasket was there. I cant really understand why they didn't install a new filter and gasket but they didn't and oh well.

So the problem is I don't actually know where the filter goes in, exactly how it goes in and exactly where it plugs into. Is there a diagram or instructions or something on how to install the filter?

Since there isn't one there for me to look at and take out. I don't know exactly how the new one goes in

And my second question is, what is some really good Automatic Transmission fluid to put in. I would like to put in some good quality fluid (probably not synthetic for now) I don't mind paying a bit extra money.

Any recommendations for some good quality ATF for the 4L60E?

Thanks for the help guys. I will let ya know how it goes.

exracer · January 29, 2008

who ever installed that tranny for ya should replace it for free....thats the reason they overfilled it because with no filter you would have to drop in a extar 5+ quarts to even get the thing moving

chances are that tranny is now junk and will self destruct soon

OUMike · January 30, 2008

Automatic transmissions are incredibly complicated. I reccommend you take it to a good trans shop and let them worry about it.

nx02nx02 · January 30, 2008

I did a tranny service on it and it seems to be working good now. I drained all the old fluid out, put a new filter and gasket on and carefully filled it to the right amount and it is working good now. I dont think it is even slipping at all.

I think what happened is at first the overfilling caused the slipping. Then after a few hours of major leaking (because they didn't put a gasket on)there wasn't enough fluid in there and it began to slip really bad. Had to rev it to 1500-2000 rpms to get the truck to move.

But after doing the tranny service on it, it seems to be fine now. I just hope that all this didn't do any long term damage to the transmission. I drove it about 15 miles overfilled and about 10 miles while 4 or 5 quarts low on fluid. And drove it that whole time with no filter on and no gasket leaking a lot of fluid.