4 Speed Auto

[turbotrana]

Do you give your box a hardtime with heaps of laboured burnouts or do you just drive normally but with a heavy foot.

With mine both times it has started to get noisey before it let go.  The first time it locked up and I couldn't get reverse, dolly wheels in the driveway was fun not!

All the other gears were hard to get but once in 3rd (1 to 1) I could drive it to the auto place.

Next time it was just noisey everywhere but I knew what was wrong and drove straight there.

Bands are a different story, you usually only lose 2nd and 4th but 1st and 3rd will drive ok.

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Edited 11/07/06 10:20 AM by turbotrana

[Ninka]

The trans actually came out of Hiddeous' ute, and it had been rebuilt and supposedly strengthened, something Kewish could not confirm

Frankly it looks as if Hiddeous has been taken for a ride

As far as I know the trans has not been abused, but just driven in a spirited fashion, but nevertheless the damage is obvious.

Dave from Kewish tells me this kind of damage is not uncommon, which is why the temper the gear sets to make them less brittle.

[SHOCK]

Finally, a thread were an auto broke, these are rare.

Anyone smashed the 6 speed yet?????

Would have thought it would be standard practice to stress releive the gears out of the factory...especially for a performance car.....obviously not...what about any other heat treatment...case hardening or nitriding

[Ninka]

Finally, a thread were an auto broke, these are rare.

Anyone smashed the 6 speed yet?????

Would have thought it would be standard practice to stress releive the gears out of the factory...especially for a performance car.....obviously not...what about any other heat treatment...case hardening or nitriding

←

It didn't actually break

Car was driven till the day the trans was removed, and I am confident Luke knew nothing about this damage until we pulled it apart.

[SHOCK]

Finally, a thread were an auto broke, these are rare.

Anyone smashed the 6 speed yet?????

Would have thought it would be standard practice to stress releive the gears out of the factory...especially for a performance car.....obviously not...what about any other heat treatment...case hardening or nitriding

←

It didn't actually break

Car was driven till the day the trans was removed, and I am confident Luke knew nothing about this damage until we pulled it apart.

←

Instead of nabbing me for "a form of speech" can anyone answer the last question....the important part of the thread (not that I have many)

cheers

[Ninka]

Finally, a thread were an auto broke, these are rare.

Anyone smashed the 6 speed yet?????

Would have thought it would be standard practice to stress releive the gears out of the factory...especially for a performance car.....obviously not...what about any other heat treatment...case hardening or nitriding

←

It didn't actually break

Car was driven till the day the trans was removed, and I am confident Luke knew nothing about this damage until we pulled it apart.

←

Instead of nabbing me for "a form of speech" can anyone answer the last question....the important part of the thread (not that I have many)

cheers

←

To do anything other than relieving the stress in the metal by gentle heat treatment is probably not feasible.

If other types of hardening were to be used, you would first have to temper the material by significant heat treatment, and thus you would likely cause distortion of shaft and gear sets, resulting in noise.

I spoke to David from Kewish, and he said they had looked to a gear cutter for better, stronger gear sets, and this can be done, but cost is a real issue, as these gears are not easy to make.

See no splitting of hairs

[SHOCK]

Finally, a thread were an auto broke, these are rare.

Anyone smashed the 6 speed yet?????

Would have thought it would be standard practice to stress releive the gears out of the factory...especially for a performance car.....obviously not...what about any other heat treatment...case hardening or nitriding

←

It didn't actually break

Car was driven till the day the trans was removed, and I am confident Luke knew nothing about this damage until we pulled it apart.

←

Instead of nabbing me for "a form of speech" can anyone answer the last question....the important part of the thread (not that I have many)

cheers

←

To do anything other than relieving the stress in the metal by gentle heat treatment is probably not feasible.

If other types of hardening were to be used, you would first have to temper the material by significant heat treatment, and thus you would likely cause distortion of shaft and gear sets, resulting in noise.

I spoke to David from Kewish, and he said they had looked to a gear cutter for better, stronger gear sets, and this can be done, but cost is a real issue, as these gears are not easy to make.

See no splitting of hairs

←

cheers Nink,

most of the gear cutting Im fimilar with (around the 4.4metre diameter mark and 23 tons each)are mostly flame hardened with the parent material being a high chrome and manganese for toughness(please dont ask for specs, Im not a metelurgist..just a wannabe one)

Not sure what material what be used for T parts??? would have thought 4140 or 4340 (high tensile bar stock)similar to that of my slightly larger version

[turbotom]

Seeing as this thread is about the 4sp auto , and getting some attention, I'll post here rather than start another one....

In regards to the ongoing problem with the band breaking on the 2-4 drum, has anyone attempted to make a stronger band?

I'm told by my trans builder that the bands I have in the rebuilt box at the moment are the strongest available off the shelf.

He has suggested it may be possible to get a custom band made with an extra layer(s) of kevlar and carbon fibre......

Have any of the other trans gurus suggested or tried this?

The box gets pulled out on monday, and I'll get confirmation on what has let go and what can be improved.

I thought about going the path of link/phil/IceMyButt and fitting a modified C9, but that's a bit too costly for me at the moment .... I've got to rebuild my vette motor first.

hmmmm.... methinks I'll get it operational with new bands for now, and get the torque tags adjusted.

A few guys have stated that the band tends to break whilst cruising, rather than full load.

Mine let go on decel after a 3/4 throttle burst.

If I can reduce the shift shock on light loads, whilst maintaining the line pressure for full throttle, it may provide better reliability.

Can I get some confirmation... Dean? Craig? others.

Oh well..... there's some truth in the old saying....

"If You ain't breaking things, You ain't trying hard enough!"

tom

[Ninka]

I know Craig (geea) have some development band that was tried.

Not sure of the result though

[turbotrana]

I reckon the band can be modified by butchering one band and tigging another layer of steel on the outside of the band to be used then getting the band relined. Something I propose doing once the need arises

Now that you mention the bands seem to break while on cruise or decel, on my auto mods on BTR 4sps I have no transmission braking on decel. I wonder whether this has helped them survive a bit better.