Clutch wear on automatic

[tonymz]

Hi all,

Is there anyway I can know the condition of the clutch in my automatic surf without removing it? It sometimes seems like the gearbox is clutching too much...

[marky]

Hi all,

Is there anyway I can know the condition of the clutch in my automatic surf without removing it? It sometimes seems like the gearbox is clutching too much...

Autos dont have a CLUTCH like a manual car.

[Driver]

Could be whats known as the BANDS inside the Autobox these can start to slip and is very expensive to repair . Check and or replace ATF Fluid is cheapest first option and make sure it is correct type and good quality Fluid and make sure all fluid is totally drained off/out because a lot of fluid can be left inside torque converter even when no more is draining from drain plug. Have a search through threads to find out how to do this . Good Luck.


Andy.

[TonyN]

Could be a problem with the torque converter, this is what initally takes up the drive, for popular yank autos, you can buy different stall speed converters, so you can pick the rpm the converter hooks up when pulling away.

clutch bands tend to slip, not tighten when worn.

as has been said, a good flush and fluid replace is always the first stop for slushbox troubles.

[tonymz]

Would the ATF fluid be the gearbox oil which can be checked through the front like the engine oil? The red kind of oil?

Sorry about the clutch question but I have no idea how the auto gearbox works.

I take it that once it stops working the best thing is to replace it since it will probably cost more to repair, right?

Cheers.

[TonyN]

Would the ATF fluid be the gearbox oil which can be checked through the front like the engine oil? The red kind of oil?

Sorry about the clutch question but I have no idea how the auto gearbox works.

I take it that once it stops working the best thing is to replace it since it will probably cost more to repair, right?

Cheers.

Yup, you need Dextron II ATF oil. Its cool, a good autobox shop should sort the box OK, most autoboxes are repairable/rebuildable, a new box will be megabucks and is rarely needed, or just get a used one but there now telling how good they are and you take a chance.

If you get a recon box, make sure the place is reputable, its easy to give it a steam clean, change the oil and call it 'rebuilt'.

Definatly give it a good flush and change the oil before writing it off, and remember the shifts are controlled by the ECU on EFI Surfs, and loose connections/broken wires/split vacuum pipes will cause odd behaviour.

[tonymz]

Thanks.

I have actually replaced that oil just a few months ago and it is showing full when using the dipstick. How often do you have to change it? I did a service about 3 months ago and changed all oils, diffs, engine, gearbox....

The behaviour of the gear changes is what worries me, when revving high I notice that when the gear changes I get a sudden burst in the revs which then drops back a little again, is this normal?

Cheers.

[dirtydog]

same as me - although now ive done the EGR mod the other day it doesnt seem to do it as much.... from 2nd to 3rd if i red line it it kinda revs a little after the shift then settles.
Im gonna do the fluid and see what happens but any ideas? Coiuld it be clutch bands???

[Guest]

Tony.

From your last post I would suggest that the cluth bands could well be on the way out, however I would suggest the change of transmission fluid first.

Gear changes in an auto baox are hydraulic controlled either directly through a valve body or electronically via servos.

If there is insufficient hydraulic pressure in the box caused by direty oil or a dirty filter, then you will not have enough pressure to hold in the clutch bands however as they heat because they are slipping they will tend to grip better.

Auto boxes are actually a lot less complex than people think, the actual mechanics behind it is quite complex but when it comes to overhauling them, the Auto boxes tend to comprise a lot of rather big parts that need to be replaced as a unit. Did a complete overhaul once on a TH350 Auto box (Out of a Camaro) in 2 hours including a new valve body and a new high stall converter.

Most problems on Auto boxes are either the Torque converter leaking because of vibration problems caused by bearing failures, or more commonly dirty transmission fluid. Remember the AQF has to act as lubricant, coolant and also hydraulic fluid to actuate the box, it needs to be looked after if you expect it to do a good job.

Cheers

[tonymz]

hmmm, just looked at the fluid in the autobox and found it to be overfilled, is that a problem? should I take some out?

Also, having changed the fluid only 3 months ago, do I need to change it again? how often does it need to be changed?

Cheers.

[Guest]

Yes you need to drain some off, however you also need to check the level in the correct manner.

Start the engine with it in park allow it to warm up for 5 minutes or so, move the gear stick through all the gears one by one and back to park.

Check the level with the engine running and the box in park.

You should change the transmission fluid about every 50K miles.

Cheers

[tonymz]

Thanks again. I will do that. By the way, before you said it could also be a dirty filter, is there a filter for gearbox? if yes, where is it and what type so I can get it changed, I have changed all oils and filters except gearbox filters as I do not know the existance of any.

Cheers.