New problem with transmission

[minifridge1138]

Hey everyone,

My transmission came down with a new problem today. When I'm at a dead stop and give it sudden throttle the car hesitates (the engine revs, but the car thinks about moving) and I hear a scraping/grinding noise from the transmission. I first noticed it when stopped on a steep incline.
If I feather the gas and let the car have a rolling start, then there is no hesitation and no noise. This only started today.

I've never had a transmission slip before, so I don't know if that is what is happening.

Another issue that may be related, If I drive for extended times on the highway (more than an hour) then when I get back into a town the transmission revs higher before shifting. Only a few hundred RPMs higher, but enough that I notice it.

I just put in a new transmission filter and 5 quarts of fluid. It is the same type of fluid and filter i put in 2 years ago and I never had a problem before.

Any ideas or suggestions?

 

[Curtis]

Are you certain your transmission is full of fluid???? Most automatics hold at least twice as much as the 5 quarts you put in.

 

[gmjunkie]

Are you certain your transmission is full of fluid???? Most automatics hold at least twice as much as the 5 quarts you put in.

I agree!!On a older tranny sometimes you need to check them several times!! Sitting,fluid will drain back out of the converter if it sat for 3-4 days and you must get them filled back up by shifting into drive and reverse several times till you get the air out!!

 

[minifridge1138]

I'll spend a few minutes going between reverse and drive and then re-check the level.

What are the symptoms of overfilling a transmission? (Just in case I get overzealous).

Thanks everyone!

 

[gmjunkie]

I'll spend a few minutes going between reverse and drive and then re-check the level.

What are the symptoms of overfilling a transmission? (Just in case I get overzealous).

Thanks everyone!

It will blow fluid out of the top vent after it's hot and running down the road!!

 

[minifridge1138]

Ok, I went between R and D for a while and drove it up and down the street.
When I checked the fluid it was between the add and full marks, so I topped it off.

The noise was still there, but not as severe.
Drove it some more, and topped it off again.

The problem did not improve.

I checked the level and it is now above the full line, so I guess I'll have to use a small hose and suck the excess out through the dipstick tube.

But the problem never went away.

Any ideas?

 

[TimAT]

700R4 in an 82? Making noise? kind of a grinding? Pull the pan and see how much metal is in there. I'll bet the rear planetary came apart. Unless you got stuck and rocked it from D to R and got it hot enough the 2-3 shift valve stuck.

 

[minifridge1138]

No metal in the pan.

This problem started after I replaced the trans filter and replaced the rod end clip.

I got everything put back together, filled it with new fluid, and now there is a noise if I am aggressive from a dead stop.

At a 5 mph roll, I can go WOT and there is no noise.

Suggestions welcome!

 

[gmjunkie]

My guess the problem is the Low Reverse sprag assy has took a Dump!!
Sprag assy is a one way roller like in a ratchet!!

As far as Transmissions go you can speculate all day,but you'll never know for sure till she has the guts laid out on the table!!


PS Do you know the difference between a Automatic Transmission and a Milling Machine??
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About 0.001

 

[minifridge1138]

I was afraid of that....

There are no shops I trust around here.

The one that is widely regarded to be the best really screwed up my friend's car.

I'm going to have to think about this for a while.

 

[82X-FireVette]

I've been following your transmission threads. You replaced a clip on the internal linkage, which indicates you have the original trans or an early version. The correct filter may be hard to get for that model due to its age.

There are several different filters for the 700R. If your trans is an original '82 version, you need to get the one for that year. If you or a previous owner installed a rebuilt newer version of the trans, say an '88 to '92 version, you would have to get the filter for the year of the new trans, not the year of the car. There is a rubber seal where the filter inserts into the front pump. If you didn't take the old one out and installed a new one on top of it, guess what? you will have problems. A wrong filter could do the same thing. The pump will suck air and will work real weird, maybe even getting damaged (you'd find metal shavings in the fluid). If you put a 4L60E filter in ('93 and up), it will not fit right as the tube diameter is different. It almost sounds as though your pump is sucking air at first and then gets a drink of fliud. That is why the other correspondents think the fluid is low. I would check to make sure you got the right filter for the trans you have.

 

[minifridge1138]

The filter I bought matched the filter I removed (no way to know if that was the correct one) and matched the part # for my year. I did remember to remove that rubber gasket. I forgot once on a buick I worked on. Luckily i realized before I put the pan on, but still had to spend an hour trying to get the gasket out now that it was wedged up in the transmission.

I let it sit for a few days, and the fluid went from being too high to just perfect.

While searching for 700R4 troubleshooting tips, i discovered that Holley carburetors need special mounting brackets if they are used with a 700R4.

They said that if the bracket isn't attached and adjusted correctly, then the transmission will slip.

I bought and installed those brackets, re-adjusted the TV cable, and the problem went away. It is now shifting stronger and more aggressively. The car is a lot more fun to drive

It is entirely possible that there is still a problem, but the symptoms are gone and that is good enough for now. If the problem comes back later, then I'll be making a call to Bow Tie Overdrives. I called around and the cost to remove, rebuild, and install a 700R4 is within $200 of buying a new one.

 

[TimAT]

The 700R4 and the 2004R are very critical to TV cable adjustment, 1 ro 2 clicks from correct is enough to make a huge difference. And both are difficult to ge tthe fluid level correct too.

Here's a tip- I used to do this all the time when I was building trannys in Chevy dealers- once you get the correct adjustment on the TV cable, back it up 2 clicks. It'll make it shift a bit more aggressively- and that alone will make the clutches last longer. Less slop during the shifts, and it'll hold each gear a touch longer. And make sure 100% that the convertor is locking up as it should. The convertor locking is part of the cooler circuit. When it locks, the pressure thru the cooler jumps 125 PSI and instant more cooling.

 

[minifridge1138]

My torque converter does not lock up.
I know because the computer controls the converter, and my car has been retrofitted to carb and the computer removed.