Had anyone had their Auto gearbox break?

sprjenkins · 28-04-2008, 11:48 AM

Hi guys.

I was wondering if anyone has had their automatic gearbox break. I've just put in a new head and cam and pushed out 440nm on the dyno so i'm a bit worried its all gonna go bang.

What power levels are these boxes capable of and is the manual any better.

Cheers Joel

FGII-XR6 · 28-04-2008, 01:18 PM

there are some good rebuilders for the BTR around I think GK got his done recently. not a cheap job ( but thats the world of performance) but AFAIK you can build up a tough box with the right gear and expertise. good luck

RG · 28-04-2008, 03:30 PM

Mines still doing well and I'm pushing out a fair bit more than that, not too much difference between the 6 & 8 box either IIRC.

The T5 will break long before the old BTR does.

sprjenkins · 28-04-2008, 04:18 PM

How much power and torque can the T5 take? I'm currently trying to weigh up whether I wan't to put in a 3000 rpm stall torque convertor and transmission cooler or put in a T5 box. There's obviously pros and cons for either route

RG · 28-04-2008, 04:20 PM

Quote:

Originally Posted by sprjenkins

How much power and torque can the T5 take? I'm currently trying to weigh up whether I wan't to put in a 3000 rpm stall torque convertor and transmission cooler or put in a T5 box. There's obviously pros and cons for either route

Can't remember the figure but if you buy a s/h unit it it is really an unknown quantity.

**Stav** · 28-04-2008, 05:06 PM

So we dont sidetrack the other thread..mate I have similar torque as yourself and I am on my 4th auto box.The rest all broke. With 550 lift and a full house sixpot engine you should do alot better than what your expecting. The cam is pretty much a race cam.In any case good luck and post up your results this week.

The Monty · 28-04-2008, 05:11 PM

MInes starting to slip, dont think its too far off now. Mums been through one, in a fully sick stock forte, lol.
Her died at 230 000, Im at 244 000.

sprjenkins · 28-04-2008, 05:15 PM

Thanks mate, i'll let you know how I go. I don't want to get my hopes up to high as you know how these things can go some times.
Pay day is on Thursday so I will try to get the parts for a manual conversion next week and put it in that weekend. I don't think i'm really that worried about breaking the box as I am of being an hour and a bit away from home and being stuck there because I blew the box up racing.

FGII-XR6 · 28-04-2008, 06:42 PM

Quote:

Originally Posted by Stav

So we dont sidetrack the other thread..mate I have similar torque as yourself and I am on my 4th auto box.The rest all broke. With 550 lift and a full house sixpot engine you should do alot better than what your expecting. The cam is pretty much a race cam.In any case good luck and post up your results this week.

maybe your avatar will give a clue as to why

**Stav** · 28-04-2008, 06:44 PM

First one blew when it was a stocker.Truth be told.That doesnt help but heat is our enemy.Gearboxes die because of traffic and road congestion.I have a transmission temperture gauge which tells me the real deal..

Mr Hardware · 28-04-2008, 07:00 PM

on a stock au i6, expect a properly serviced, non abused box to easily reach 300,000klms easily. as soon as you start trying to run 14sec quarters, it seems these boxes die rather quickly, due to the abuse and power through them. Cabbies routinely see 400, 500, 600+k out of these stock BTR boxes.

Quote:

Gearboxes die because of traffic and road congestion

yeah. right. you just keep on telling yourself that buddy. the fact that cabs that spend THEIR ENTIRE LIVES contstantly traffic bashing doing half a million on a box says that you're just plain wrong.

**Stav** · 28-04-2008, 07:10 PM

Hum? My temp gauge does go its highest at idle in traffic. First box died a natural death second box from a rear main seal...abused...next box was second hand jobbie which was dodgy from the beggining.Last box with the advice of forum members it got beefed up.

For sure abuse wrecks the box but heat is the main culprit and hence transmission coolers are recommended.

Sox · 28-04-2008, 07:22 PM

Quote:

Originally Posted by Stav

Hum? My temp gauge does go its highest at idle in traffic.

Whilst it may get hot in traffic, it isn't under much strain, so can quite easily cope with the heat.

Quote:

First box died a natural death second box from a rear main seal...abused...next box was second hand jobbie which was dodgy from the beggining.Last box with the advice of forum members it got beefed up.

Ok, so none of them really died because of the extra power.

Quote:

For sure abuse wrecks the box but heat is the main culprit and hence transmission coolers are recommended.

Heat AND abuse is the main culprit, as heat on it's own won't cause a lot of problem.

These boxes are actually very strong when in good condition.
Decent coolers are a no brainer as far as I'm concerned, and with one, I can't see why they wouldn't last a goodly amount of time behind a very heavily modified N/A 6 pack.

Don't forget, XR6T's have essentially the same box, and they have bucket loads more torque than we'll ever see with an N/A 6.

A good cooler and plenty of new good quality oil is the key.

Rick.

**Stav** · 28-04-2008, 07:23 PM

Yep.Definately.

sprjenkins · 28-04-2008, 07:41 PM

Yeah, I was speaking to the auto trans guy today and he said that they hardly ever see a box come through for reco that has its fluids looking in good condition. He said the key was good regular maintainance. Also he said that if your going to abuse the car every once in a while the auto will probably hold up but if you want to do it on a regular basis get a manual gearbox.

Still as good advice as that is its not really a definitve figure of how much torque the box is rated to.

private9 · 28-04-2008, 08:36 PM

Quote:

Originally Posted by Stav

Yep.Definately.

Um, I don't know if I'm seeing straight..... but, did you just agree with Sox?!?! I must say, as soon as I saw you both in the same thread, I got a little excited! Gotta be honest here and say I was disappointed - a bit of controversy/debate would've been entertaining!!

Back on topic, with a decent cooler, a well serviced and non-abused one should cope with anything that any of our AU6s can throw at it. Sorry, but I've never heard of any EA-AU 6 that has killed a tranny purely with monstrous power. Abuse and neglect yes, but purely with power no!

A proper mechanical shift kit (MV Autos SA have a very good rep) should help as well, by firming up the shifts and reducing some heat. A higher stall torque converter will add heat back in (hence the need for a decent transmission cooler) but it will make things very entertaining!

**Stav** · 28-04-2008, 11:25 PM

Quote:

Originally Posted by private9

Um, I don't know if I'm seeing straight..... but, did you just agree with Sox?!?! I must say, as soon as I saw you both in the same thread, I got a little excited! Gotta be honest here and say I was disappointed - a bit of controversy/debate would've been entertaining!!

Back on topic, with a decent cooler, a well serviced and non-abused one should cope with anything that any of our AU6s can throw at it. Sorry, but I've never heard of any EA-AU 6 that has killed a tranny purely with monstrous power. Abuse and neglect yes, but purely with power no!

A proper mechanical shift kit (MV Autos SA have a very good rep) should help as well, by firming up the shifts and reducing some heat. A higher stall torque converter will add heat back in (hence the need for a decent transmission cooler) but it will make things very entertaining!

Sorry to dissapoint you. Sox is right.

El Sucio · 29-04-2008, 08:01 AM

What classifies as regular servicing?

I'm looking at an entry level snort turbo for my XR Auto, I already figured on a tranny cooler and an adjustment to the shift itself to extend it's life.

Once these boxes do go to meet their maker, is it worth changing to a T5 manual?

Sox · 29-04-2008, 08:13 AM

Quote:

Originally Posted by El Sucio

What classifies as regular servicing?

If behind a fairly powerful engine >180rwkw, then I would at least dump the oil every 20,000k's.
And I'd probably rip the tranny out and empty the convertor every 50,000k's.

Quote:

I'm looking at an entry level snort turbo for my XR Auto, I already figured on a tranny cooler and an adjustment to the shift itself to extend it's life.

Sounds sensible.

Quote:

Once these boxes do go to meet their maker, is it worth changing to a T5 manual?

Depends what you want.
A T5 isn't stronger than the BTR slushy, in fact the slushy is stronger than the T5.
However, the T5 being a manual is just so much more of a drivers box. It's difficult for me to make a comparison here, as I hate autos with a passion. I have yet to drive an auto which truly satisfies me. They all feel like crap when comparing to a manual (even the new 6spd auto). You lose the relationship you have with the engine when using an auto.

So it's not really which is stronger, as they both are strong enough, to a point. It's more to do with which one you prefer, and for me it's a manual all the way.

Rick.

**Mechan1k** · 30-04-2008, 09:44 AM

Under heavy load and traffic driving .... I had my transmission replaced with one that was already built for someone else ... deal fell though ... I picked it up. Was built strong for a boosted I6.

That in conjunction with a decent sized transmission cooler has helped tremendously. I don't race the ute ... but it doesn't get driven like a grandma either ... I do also manual shift it a fair bit too when loaded up (not overrevving/racing it though).

I get mine serviced every 20,000km with a service kit since the rebuilt item went in ... I think my first trans was initially damaged by lack of servicing more than anything ... and no cooler (heat is a contributing factor).

Now I have a very firm shifting 4-speed auto that handles load nicely ... and has a very positive shift (without thumping into gear).

I think it is well worth spending the $$$$$ on a well built box if you want it to last.

5.0 ED · 30-04-2008, 01:41 PM

I've had a stock BTR behind a turbo 6 pushing 271rwkw's and 1100nm touque, auto handle it fine no probs with a suitable electronic shift kit, i have only even broken 1 off these auto's any other problems have been caused by heat/wear/slipping on changes due to not doing a shift kit.

The one i broke had a 5l pushing 219rwkw's and was dropped into gear at 8000rpm, tranny/diff both went bang in unisen, made a hell of a mess. destroyed the diff, blew the casing apart from flying bits. As for the auto it broke the one way lock up bearing which cant remember what its called, then bits of it jammed the oil pump and broke the touque converter tungs which drive the oil pump. This one way bearing is the weakest part i can find in a BTR.

I've heard of testings done on standard BTR's, i think nizpro did one, and they break at over 700hp.