needadvice

SO.........

Day 1
Everything is great with the tranny.......coming to a slow gradual stop at a traffic light in traffic, as I get to about 5-10mph with my foot on the brake.....the tranny free spins.

I'm like..HUH.....light turns green and the car sits still as it revs in "3". I put the shifter into "2" and it goes into gear normally and I take off. It starts out in "1st" and shifts normally into "2nd", then as I pick up speed, completely casually, I put it into "3" and it shifts into "3" normally. It drives the rest of the day normally...upshifting, downshifting, etc.....

DAY 2
I back out of my driveway in "R" and then put it into "3" to pull away, and NOTHING again, it just free spins. I then put it into "2" and pull away and shift into "3" manually again and it shifts into "3" normally like on Day 1.
BUT.....when I leave it in "3" after driving it down the street and I slowly come to a stop at a light or stop sign, it will free spin at about 5-10mph (pops out of gear) and NOT go back into gear unless I put it into "2" to get going again.

Day 3.....today
Now, it will only get moving by starting out in "2", then manually shifting to "3". But a couple times today it popped out of gear (free spun) while going steadily at 35mph down the street. I had to drop it manually down to "2" to get it to go back into "2", then I shifted into "3" and it was normal again in "3". UNTIL I came to a stop again, then it will pop out at about 5-10mph......

SO........It will NOT go into forward gears with OD or 3. I can only get the car moving forward by starting out in "2".
Once its in "3" or OD......it drives normally. Even romping on it. So once its in "3" or OD it holds the gear normally. I DO have tranny braking (manual downshifting) for all gears.
Fluid is perfectly clean....no burnt smell at all...full.

SO....MY GUESS.....what is causing me to lose line pressure in "3"....and what is causing me to lose line pressure while in "3" at slow speed (5-10mph).

I'm assuming its the loss of line pressure that is popping me out of gear in "3" and in "OD" at slow speeds.

One more thing......when I shift from "2" to "3" to get going.....if I keep my foot on the gas while putting it into "3" it will give me a quick rev, then pop into gear. If I slightly lift my foot off the gas while putting it into "3", it will go in nicely, almost normally.

What the hell..........my friend with a 4L60E says it could be a worn valve body or the pistons in the pump.....whatever that means....



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Vince B

iTrader: (1)

Damaged input sprag!

needadvice

I thought if the sprag goes....you have no tranny braking (downshifting). This thing has full, normal tranny braking when downshifting manually.

And how does it work in "3" totally normally once I trick it into "3" by starting out in "2"..............but it will not start out in "3"?

Vince B

iTrader: (1)

The reason why the trans shifts to 3rd gear manually from second is because the over run clutch comes on to aid the input sprag. In 4th gear normally the sprag over runs (freewheels) so that is why you get 4th gear manually shifting from D3. Because your sprag is broken you have no movement in the OD or D3 range from a stop. The reason why you get movement in the lower gears is because the band or the low reverse clutch comes on in the manual ranges with the forward clutch being applied. The tranny breaking(engine braking) that you are talking about is the over run clutch being applied in manual ranges like D3 M2 or M1. HTH Vince

needadvice

Well damn, thanks for that explanation.

So, will this thing last like this for awhile....or will I lose 1 and 2 any day now sitting in traffic.....?

I mean if I drive it easy, can I make it 1 month?

.

Vince B

iTrader: (1)

Sorry I dropped my crystal ball last week and I don't have that answer! Honestly thats a hard one to answer. I have never tried to push one to see how long it would last. I would guess if your lucky it might last that long. Vince

Predator T/A

iTrader: (7)

keep in mind you are only having forward motion with 2 very small clutches they wont last long

needadvice

Alright man, well I appreciate the info. I just can't do anything with it for 1 month, and its my daily driver. Hope it lasts.

Thanks again........

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needadvice

I wish I would have known that as soon as it started, I would have babied it. I have done a few WOT runs after it has shifted to "3" just to see what would happen and to answer a tranny guys questions what was happening.

I guess those are two pretty good clutches......I'll take it easy and hope it lasts 1 month.

Thanks.

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PBA

You have more line pressure in "1" or "2" shifter position, because it accesses the intermediate/reverse boost valve in the fornt pump. The "falling out" of gear tells me the pressure is down below what it should be to hold the gear at the lighter throttle openings when in "D" or "OD" shifter positions. The overrun clutches do not come on when in manual "2" until it makes the 1-2 shift. I would put a pressure gauge on this and see what the nuimbers are. You most likely will find the numbers are low at light throttle openings. Excessive rotor clearance will do this, as would a damaged sealing ring on the input shaft, but would be alright at higher throttle openings as the pressure and volume of oil increases and covers up the leak.

needadvice

Hmmm, thanks for the info. Starting to understand these damn trannys.

I can't believe someone hasen't found an easier way all these decades.

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