Trimatic issues

**agr071** · 30-03-2012, 10:01 PM

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

**mauser** · 30-03-2012, 10:12 PM

I think the T400 sucks too much power from a 308. I always seem to like the changes in a T350 better for some reason.

Mauser

**agr071** · 30-03-2012, 10:14 PM

Would ideally like to put a turbo 700 behind it, but seeing that i already have a turbo 400, i'd use it.

**Vombil** · 31-03-2012, 01:21 AM

i had a similar noise in a WB van with trimatic. i was told by two old skool mechanics that it is very common and nothing to worry about. I had a T400 behind a 308 and it was sluggish

**Taily** · 31-03-2012, 07:36 AM

Originally Posted by agr071

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

**buck** · 31-03-2012, 07:38 AM

They dont call them traumatic for nothing, my dad had a 308 with traumatic when new, (1979) blew up in 40,000klm and replaced under warranty at extra cost with a stato turbo 350 i think, did 400,000klm no problems.
every person i have known with a traumatic has blown it up and they dont seem to be able to fix them properly for long term use, i have a m20 4 speed which has been rebuilt twice in 200,000klm quiet normal my mechanic says they are just weak as piss in the bearings.

**Taily** · 31-03-2012, 08:11 AM

Originally Posted by buck

They dont call them traumatic for nothing, my dad had a 308 with traumatic when new, (1979) blew up in 40,000klm and replaced under warranty at extra cost with a stato turbo 350 i think, did 400,000klm no problems.
every person i have known with a traumatic has blown it up and they dont seem to be able to fix them properly for long term use, i have a m20 4 speed which has been rebuilt twice in 200,000klm quiet normal my mechanic says they are just weak as piss in the bearings.

The cluster and layshaft (and the needles rollers) used to start losing their case hardening after about 100K - normal. On the other side of that I have seen Trimatics go for over 140,000 miles (220,000+km) without a rebuild as long at they were serviced regularly and not driven hard all the time. Thrash something (standard) and you'll break it, it is as simple as that. I can't imaging your father was easy on it or even had the auto serviced for it to "break" that quickly. A well built trimatic is well capable of handling 350-400hp very reliably and for a very long time.

No trimatic was ever replaced by a TH350 under warranty in a GMH dealership... Steve Dunne-Contant would have rejected the claim outright. Different engine blocks for starters. It wont fit, the selectors are all different, the tailshaft is different, the speedo drives are most probably different, etc etc. So they changed the engine as well? I doubt that very, very much. If it was done at all it would have been a full retail job, or probably done external to the dealership by your old man.

**wbute** · 31-03-2012, 08:26 AM

My WB is still on its original M20 at 275000km. Its a horrible gearbox like every other M20 still lol.

**RodneyHZ253** · 31-03-2012, 08:49 AM

If it ant broke don't fix it

Isn't clunking a bit normal and I though that a little bit of noise could also be normal

Drive it abit it might go for years

I had a mates father who remove a 202 from his car because it had a tick in it and put in another motor In,this motor used no oil and run well .I talked a mate into buying it and putting in his ute 20 years latter I think this motor is still ticking away .

**HK1837** · 31-03-2012, 08:50 AM

Originally Posted by Taily

The cluster and layshaft (and the needles rollers) used to start losing their case hardening after about 100K - normal. On the other side of that I have seen Trimatics go for over 140,000 miles (220,000+km) without a rebuild as long at they were serviced regularly and not driven hard all the time. Thrash something (standard) and you'll break it, it is as simple as that. I can't imaging your father was easy on it or even had the auto serviced for it to "break" that quickly. A well built trimatic is well capable of handling 350-400hp very reliably and for a very long time.

No trimatic was ever replaced by a TH350 under warranty in a GMH dealership... Steve Dunne-Contant would have rejected the claim outright. Different engine blocks for starters. It wont fit, the selectors are all different, the tailshaft is different, the speedo drives are most probably different, etc etc. So they changed the engine as well? I doubt that very, very much. If it was done at all it would have been a full retail job, or probably done external to the dealership by your old man.

Agree. Plus there was no 1979 Holden fitted with a 308 and trimatic. The last would have beem an auto SLR5000 or LX SS 308 about 7/77. There wasn't another until about 11/81 (WB Statesman or VH).
Trimatics are great boxes if rebuilt properly and serviced. If I ever have an auto standard 308 HQ-WB tonner ever again for towing i'll use a VL trimatic unless the 308 is a TH pattern then i'd use a TH400. TH350 were a terrble box when first used by GMH, ask Dr Terry about them. In basically standard form a trimatic is actually a stronger box, and both can be built to handle decent hp too. The trimatic got its bad name in HT and HG when it was just an old cable kickdown TH180, GMH redesigned them for the HQ and LJ.