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700r4 rattles in first gear?

nutt7

nutt7

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Today I noticed a rattle/grinding noise when the tranny is in first gear. When it shifts to second, it's quiet as it should be. If I hold it in first and let off the gas to coast, the sound is worse. What could this be? I am camping this weekend (only taking my vehicle), and if first gear takes a dump, can I still drive it?
 
It does it in reverse too, even louder. I jacked up the wheels and it shifts in and out of first fine, its just noisy. Rattle is certainly coming from inside the tranny...it MIGHT be a little louder on the output side, but it's hard to tell.
 
Here's what I found online (this is for 4l60, but it showed up for 700r4 searches too):

Problem: Transmission seems noisy when moving in 1st and Reverse, noise goes away instantly if you shift to N or the Transmission goes into 3rd gear
Symptoms: Reaction planetary is worn out due to high miles or insufficient lubrication. Not a critical failure, but not a good sign either.
Possible repair: Remove & replace or rebuild sooner rather than later.

and/or

Problem: Needle bearings in the pan, first gear and/or reverse may be noisy
Symptoms: Either a torrington bearing or a planetary bearing is on its way out. Transmission will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts). It is drivable until it breaks.
Possible repair: Remove & replace or rebuild

Crap. No camping trip for me...
 
Also, it's shifting into OD like 5 mph higher than normal. Fluid level is fine, fluid is bright red. I will check the coolant tomorrow to see if its mixing with the atf. Does any of this sound familiar to anyone? My auto tranny knowledge isn't so extensive. Any confirmations or advice is welcome.
 
Everyone I have seen with that compliant has had smoked planetaries, 2 this year 1 last year. They were all 4l60e's though. A thrust bearing or washer usually only causes a whine. The rattle suggest it is more than that. If they let go completely you will be stranded. If it is the planets it will not be long to it lets you down.
 
It makes the sound only while the vehicle moves, right? That makes it one of the planetary sets or a bearing/sprag. If the noise happens at a standstill, only the pump and TC are moving - I don't know why that problem would stop when it shifts gears. I can't think of anything fitting your description than can be fixed without pulling the tranny.
 
Blue85 said:
It makes the sound only while the vehicle moves, right? That makes it one of the planetary sets or a bearing/sprag. If the noise happens at a standstill, only the pump and TC are moving - I don't know why that problem would stop when it shifts gears. I can't think of anything fitting your description than can be fixed without pulling the tranny.
Click to expand...

It only makes noise when moving. Is there a part (planetaries) that can be replaced or will I need a full rebuild?
 
If a planet failed it will require a full tear down. There will be metal shavings all through the transmission. Prolly be melted bushings too. I would not dare to try & scab one back together after a failure like that.
 
boz42 said:
If a planet failed it will require a full tear down. There will be metal shavings all through the transmission. Prolly be melted bushings too. I would not dare to try & scab one back together after a failure like that.
Click to expand...

Thanks for the info, I guess I'll drive it til it breaks.
 
So now it shifts late, and very hard. It eases up a little once warmed up. Could fragments of the planetary cause this? I decided to not drive it anymore until I fix it.

Another thing: I have a remote screw on filter before the fluid hits my cooler. If my fluid has always been perfect, do you think it is necessary to flush the lines? I would do it, but I have no clue how to do this at my house.

And one more thing: Will a 700r4 from a 94 work in my 89? I assume that since they are both K cases, they should work...:dunno:
 
Yes, fragments of the failed planet can hang valves for sure, and could make it into the cooler depending on which side of the lines the filter is on. That 94 trans will be a 4L60E, no interchange on that one.
 
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