A transmission in distress?

Post by **FireFox31** » 31 Jul 2022, 20:59

The transmission on my 2000 V70 NA automatic with 227k miles seems to be in distress. How bad is it based on these symptoms? How much will a fluid flush help? Or should I skip the flush and bring it to a transmission shop?

I will start by confirming the correct fluid level. What's the exact temperature at which the fluid level must be read? Can VIDA tell me the transmission fluid temp and how accurate is it?

Symptoms I can consistently reproduce:
1. Quick RPM drop at 44 mph, 1900 rpm, probably 4th gear. Torque converter indecisive about lock or unlock?
2. Slow to engage 3rd gear during 2-3 shift at low acceleration. In no gear for ~1.5 seconds allowing gas pedal to rev RPMs.
3. RPMs fluctuate between 1200 and 1500 RPM when coasting from 35-40 and 45-50 mph. This video shows the RPM fluctuation. Also happens when manually shifted into 4th, stops when shifted into 3rd.
4. Power cut-outs using cruise control at 40-50 mph going downhill. Only experienced this once. Fuel/misfire issue?
5. Shifts are a little slower than another 2000 V70 in side-by-side comparison.
6. Valve body may have a tiny leak, covering it with a thin film of oil.

454cid · Post by **454cid** » 31 Jul 2022, 22:31

What is that number that goes up to 99.9 on the digital display?

The way that tach drops/bounces makes me think it's electrical, but I'm just guessing. That's weird.

Post by **abscate** » 01 Aug 2022, 04:57

That’s his mpg …awesome on coast.

Firefox…I think that’s the TC locking amd unlocking. The rev drop perfectly matches. I bet you feel a slight bump each time it wavers? Deceleration whenrevs go up, free wheel when revs go down?

Post by **FireFox31** » 03 Aug 2022, 23:19

Is the torque converter something separate which could be serviced or replaced? I'm hesitant to flush $100 of transmission fluid through the car if that won't work and a repair will require it to all be drained.

Post by **matthew1** » 04 Aug 2022, 14:34

How old is the fluid? What's the color? I'd do a drain n fill before a flush.

I did some math on drain and fill, and on a P80 4-speed, you'll be at 77% new, 23% old fluid after you use a dozen quarts.

yanga001 · Post by **yanga001** » 05 Aug 2022, 06:16

FireFox31 wrote: ↑03 Aug 2022, 23:19 Is the torque converter something separate which could be serviced or replaced? I'm hesitant to flush $100 of transmission fluid through the car if that won't work and a repair will require it to all be drained.

Had a slipping transmission the other day and fingers crossed the last 200-250 km have been trouble free in terms of shifts. If you caught it early a fluid flush makes all the difference. I would say check the drain plug to see how much wear and the size of shavings.

Post by **Krons** » 06 Aug 2022, 05:44

matthew1 wrote: ↑04 Aug 2022, 14:34 How old is the fluid? What's the color? I'd do a drain n fill before a flush.

I did some math on drain and fill, and on a P80 4-speed, you'll be at 77% new, 23% old fluid after you use a dozen quarts.

I'm in the drain and fill camp when over 150k miles. I've done a cooler return line flush on two cars but was nervous of the new fluid detergents breaking contaminants loose and clogging valve body.

My 08 S60 I've drained and filled with Valvoline Maxlife ATF at each of last three oil changes and the fluid color is now very close to new. On my 08 it's just over 3 qts at $24/gal.

Fluid color should tell you a lot.

Post by **FireFox31** » 09 Aug 2022, 11:58

My transmission fluid appears to be quite overfilled (my fault). With the transmission at 80 C, the dipstick level was almost at the word "Do" in "Do Not Overfill". The next day with a cold transmission, it was at almost the same level. Both checks were with the engine off. When warm at idle, the transmission got to 87 C instead of the Haynes recommended 80 C.

While checking the fluid, I found that the battery negative cable is broken where it attaches to the transmission. Could that be causing these transmission problems or my misfire and lean condition?

The attached picture shows the color of my transmission fluid (unknown brand and age) after the first drain. It's compared to new Aisin fluid, of which about 3 Liters was added. When wiping the dipstick on a rag, the fluid appears a decent red.

I'm on the fast track to get my front right axle carrier bearing replaced. Draining the fluid for that is the first step to a full flush.

Post by **abscate** » 09 Aug 2022, 16:00

Overfilling will froth it and lead to shifting funnies. Definitely take your time, get the temp right, get the level right, idling in park after selecting all gears.

Post by **matthew1** » 09 Aug 2022, 16:28

The color indicates that a drain n fill would be a very good candidate for What To Try™ after getting the level fixed up.