Trimatic issues

[Taily]

I've pulled out the tired 308 & turbo 400 from the HZ and put in a mildly worked 308 with trimatic.
When Reverse or Drive is selected, it clunks hard into gear. Also gets a little whining noise until about 1000rpm.

SO - Question is:
A) Has the trimatic got an issue (it idles about 800rpm)?
B) Do i get an adaptor plate and put the turbo 400 back in?

Thanks in advance

To answer your question, a couple of questions first....

1. Is there a real delay (I mean more than 2-3 seconds ) in between selecting reverse and the box actually going into reverse? We used to work on anything up to 3-4 seconds being tollerable/OK, but with your idle RPM it should be reasonably quick into reverse due higher oil pressure.

2. When you say "clunks" into fwd or rev gear, do you mean it goes in hard (but is quiet) or just goes in normally but makes a noise? Standard torque converter fitted or a small stall? Any decent amount of stall built into the converter should have the effect of making going into gear almost un-noticeable.

3. Have you had a good look at your flexplate/bolts, your unis, and the front yoke for spline wear?

4. Apart from those things you've mentioned does it drive normally - ie, on a downshift does it thump back from 3rd to 2nd as well? - On later types there was a small plastic valve fitted to the valvebody called a dump valve that commonly breaks and causes this.

5. The $64,000.00 question..... Starting on a hill.... Can you reverse up the hill at greater than about 1500rpm? That will tell you if the geverse clutch pack is OK or not. You'll know if it isn't....:nevreness:

Trimatic pumps are known for being a little whiny, but didn't affect the operation of the unit as long as the line pressures are checked every now and again and if they start to drop off get the tranny pulled.

Couple of areas for you to have a look at to at least make a start yourself. Most autos are a little erratic if they don't have either enough oil pressure or enough vaccuum.

The TH400 question: You'll never break it (though that said mine now has a leak in the pump or converter seal I am yet to get to or get fixed) but with the size and weight of the spinning mass in a TH400 they do suck a heap of power out it - flipside: the changes are silky smooth when cruising....

Regards,

Dave

[agr071]

To answer your question, a couple of questions first....

1. Is there a real delay (I mean more than 2-3 seconds ) in between selecting reverse and the box actually going into reverse? We used to work on anything up to 3-4 seconds being tollerable/OK, but with your idle RPM it should be reasonably quick into reverse due higher oil pressure.

No, it's pretty much straight away.

2. When you say "clunks" into fwd or rev gear, do you mean it goes in hard (but is quiet) or just goes in normally but makes a noise? Standard torque converter fitted or a small stall? Any decent amount of stall built into the converter should have the effect of making going into gear almost un-noticeable.

It's as if the car was parked on a hill without the handbrake (with the load of the vehicle on it), and it gets taken out of park..That noise

3. Have you had a good look at your flexplate/bolts, your unis, and the front yoke for spline wear?

Flexplate bolts looked good when motor & box was removed from previous vehicle, Uni's felt good as well.

4. Apart from those things you've mentioned does it drive normally - ie, on a downshift does it thump back from 3rd to 2nd as well? - On later types there was a small plastic valve fitted to the valvebody called a dump valve that commonly breaks and causes this.

Haven't driven up the road yet, only the driveway, because there are too many different colours on it and i'd be embarassed to take it anywhere ATM.

5. The $64,000.00 question..... Starting on a hill.... Can you reverse up the hill at greater than about 1500rpm? That will tell you if the geverse clutch pack is OK or not. You'll know if it isn't....:nevreness:

Yes i can reverse at more then 1500 rpm.

[Taily]

No, it's pretty much straight away.

I was starting to think that the idle RPM might be too high (only just though...) for a standard torque converter.

It's as if the car was parked on a hill without the handbrake (with the load of the vehicle on it), and it gets taken out of park..That noise

Geebus... Any noise like that isn't normal at all. Any backlash in the auto driveline should be cushioned by the torque coverter, however what you're describing could be a number of things, without hearing/seeing/smelling the oil it is hard to diagnose - but it does sound like it will need someone to look at it. As long as you're sure there is nothing else loose in the driveline (yoke/unis/mounts etc) and the converter was spun in/seated properly then it does sound internal.



Flexplate bolts looked good when motor & box was removed from previous vehicle, Uni's felt good as well.

How much of the history of the box do you know? Serviced at all?

Haven't driven up the road yet, only the driveway, because there are too many different colours on it and i'd be embarassed to take it anywhere ATM.

Might be time for a night-time stealth run with cap and sunnies....

Yes i can reverse at more then 1500 rpm.

Any noise like what you describe isn't right and it could be a number of things, from too much backlash in the planetarys/worn or broken band/cracked drum/over adjusted servo piston etc etc etc.... A "warm" engine with a higher idle is likely to outgrow a standard torque converter also as they act as a clutch to cushion the driveline. does the noise etc settle down a bit if you drop the idle down?

Dave.