Torque converter symptoms?
 

Morning all

I suspect my torque converter might be worn/wearing.

What are the easiest ways of testing/telling of this is the case?

When driving around I mean.

Cheers

A torque converter is about the most basic bit of engineering other than a house brick. They rarely fail.

A "test" is to check it is holding at its stall speed.

Put the car in gear, engine warm, stand on the brakes HARD with NOTHING in front of you. Press the accelerator to the floor. The engine rpm should not exceed the stall speed of the converter (typically about 3,000 rpm).

Don't do this for longer than is required for the rpm to settle. It produces a LOT of heat.

More usefully, what are the symptoms that are concerning you?

The symptoms are hard to explain. It's possible it's just me being a worrier but the gearbox seems almost sticky with the revs if you get what I mean. It's due to have a gearbox fluid/filter flushed and replaced in a few weeks so maybe that'll sort it.

I'll do your simple test when I get home though.

I suspect the fluid and filter change will resolve the issue although your description is a little too novel for me to be sure.

Make sure you have LOTS of clear space in front of you when you do a stall test. If your foot slips off the brake pedal during the test you will be 10 metres or more in the distance before you can react.

Do you mean it hangs in a lower gear beyond the rev point at which you would expect it to shift up?

Does it change up if you take your foot off the go pedal for a moment and then put your foot back on it?

Do you also have hard gear changes?

If so, the first thing I'd check is the amount of oil in the gearbox. I had similar symptoms of a box that had been over filled.

Change the oil before thinking about anything else. There is loads of good advise in the Tech FAQ on this website telling you how to do this. That is most likely cause of your driving problems.

[QUOTE=Casheye;2605935]Do you mean it hangs in a lower gear beyond the rev point at which you would expect it to shift up?

Does it change up if you take your foot off the go pedal for a moment and then put your foot back on it?

Do you also have hard gear changes?

If so, the first thing I'd check is the amount of oil in the gearbox. I had similar symptoms of a box that had been over filled.[/QUOTE

That's exactly what I mean. It sounds like once the oil/filter has been replaced it'll stop fingers crossed. I performed the stall test and it wouldn't rev above about 2k rpm. Does that sound right?

Cheers

What car is it, engine, gearbox, year, mileage, when was the ATF last changed?

BTW, stall speed is usually in the 2000rpm region +/-300rpm, 3000rpm is the preserve of things that are designed to run at high revs and change "high'n'hard" into the next ratio.

When you do the stall test, in addition to standing on the brakes, pull the handbrake up as an additional precaution.

It's a '97 V90 with a B6304S engine, I'm not 100% on the box, 113k miles and as far as I can the oil has never been changed. Well not according to the paperwork I've got.

Cheers

First, don't have a flushing change done on the gearbox ATF - not at that mileage when it appears to have never been changed! :nah: It's likely to blow the seals internally.

Instead, if you're having a garage do it, get them to do a "sump-dump" change - drain the contents of the gearbox sump, refit the drain plug and then top up with fresh fluid to the correct level.

Repeat at monthly intervals until the fluid stays clean. Usually 3-4 of these -art-changes does it.

You'll have the AW30/40 or 30/43 box in it, if it's the 40 the stall speed is 2700rpm and if it's the 43, stall speed is 2100rpm. Out of all the boxes fitted to the 7/9xx cars (and the V70 is a development of them) most are about 2100rpm stall speed - pg 101 shows this on this pdf :

http://www.myvolvolibrary.info/Tech_...DataPocket.pdf

Oddly couldn't find a listing for the B6304S, i know they ade one so maybe i need to find another Data Pocket that lists it.

I've just typed all this and realised you said V70 - that's the FWD jobby isn't it?

I'll try to find more specific data on the box you're likely to have and data on it. The sump-dump advice still stands though.