4 Speed Auto

[turbotom]

OK.... so my band did not break as I thought.... but the kevlar lining was completely gone. Too much slippage caused frictional heat, which eventually caused metal to metal scoring of the drum surface.

Here's a couple of pics of the 2-4 band which lost its lining, and the resultant drum damage. The drum could have been machined/linished smooth, but I've opted for a new replacement.

too much applied torque is the culprit.... around 800+ Nm @ 3000 rpm

and this was still with street tyres.

More clamping force for the band is required.... or I might have to regrettably reduce torque below 3500 rpm for reliability

[saleen]

OK....  so my band did not break as I thought....  but the kevlar lining was completely gone.  Too much slippage caused frictional heat, which eventually caused metal to metal scoring of the drum surface.

Here's a couple of pics of the 2-4 band which lost its lining, and the resultant drum damage.  The drum could have been machined/linished smooth, but I've opted for a new replacement.

too much applied torque is the culprit....  around 800+ Nm @ 3000 rpm 

and this was still with street tyres.   

More clamping force for the band is required....  or I might have to regrettably reduce torque below 3500 rpm for reliability 

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Mine blew again last week.

[xrdreaming]

Yep I have worn out 3 bands just like that Tom

[turbotrana]

getting the box to shift as hard as possible helps substantially. If your gearbox builder is just doing it via the S5 solenoid, the band burning will occur prematurely. Mod the box via elimating the S5 completly takes it a step further with ultimate shifts and prolongs the life of this band. See what you builder is doing. Not all boxes are modded the same.

[Ninka]

Maybe there are enough of us around with really powerful auto's to start looking at some serious re-engineering of the box

I'm thinking of custom bands, and special gear sets, to get consistent performance with 400 rwkw or more

What do you think

[Ralph Wiggum]

Why would we need that Ninka you only want 370rwkw remember...

[Ninka]

Why would we need that Ninka you only want 370rwkw remember...

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I know, I know, but then I just got thinking, what if I try this, or that or this or that or this or that, ohh no, my world is starting to spin

[JP300]

My box just got rebuilt by one of Tunehouses engineering shops in Sydney (I do not know who) and they are giving me a 12 month warranty for the box to 400 rwkw.

I will be out to WSID in a few weeks ... See how it goes!

[ms700]

My box just got rebuilt by one of Tunehouses engineering shops in Sydney (I do not know who) and they are giving me a 12 month warranty for the box to 400 rwkw.

I will be out to WSID in a few weeks ... See how it goes!

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It will be interesting to see exactly how you go with the new box.

How much power are you putting out at the treads?

[rjs]

My box went some time ago, lost 2nd and 4th gear. I can still put it in reverse but other than that, 1st and 3rd and still holding up.

I am getting a rebuild done in a weeks time through C and V and will warranty the box for 12 months. Hopefully this rebuild should last.