TCCoA Forums banner

What happens when you do WOT 4th gear pulls

21K views 62 replies 19 participants last post by  RalphP 
#1 · (Edited)
I'll just let this pic speak for itself. If you absolutely have to go fast, for the love of all that is holy, turn OD off. Or this will eventually be the result. That drum is supposed to be smooth on the outside where the band is applied. Someone thought the torque converter failed, it held up just fine despite the damage. The OD band got fried, however.

<a href="http://imgur.com/C7AqF"><img src="http://i.imgur.com/C7AqF.jpg?1" alt="" title="Hosted by imgur.com" /></a>
 
#4 · (Edited)
All I'll say is it's not mine, thank goodness.

That band and drum got so hot that the metal on the outside of the band started to change color.
 
#6 ·
Jeminy Christmas! :zraped:

yeah, i even drop out of OD when i'm passing on the highway.... and i try to avoid using a lot of throttle out on the interstate...
 
#7 · (Edited)
Here are my pictures.

The cause of my last minute transmission woes. Lesson learned; no more top gear pulls.

On *most cars you won't see this kind of damage with a top gear pull, but when you're making close to 400 rwhp and almost 400 ft lbs of torque bad things happen.

One heavily grooved and shredded drum ...



and one burnt up OD Band ...



 
#11 ·
The OD band only applies in manual 2 and OD, so I'd assume it would only have affected OD unless something else got cooked.
 
#14 · (Edited)
Keep your HP and torque numbers close to stock and make your 4th WOT runs without risking injury to the trans.

The OD band - even the Heavy duty Kevlar one - can't withstand that kind of abuse for long when you're making the kind of HP and torque numbers that Robert, myself and a few others are making.

I suppose you could switch to a manual trans...
 
#16 ·
My guess would be a 3-4 shift at WOT. I know that's a lot of power, but I would think with increased pressure, that band would hold if power was applied after the band was fully engaged. Of course, with the TC unlocked and that torque multiplication going on....... YIKES! lol
 
#18 ·
#22 ·
Well, I wouldn't call that the "problem", just changing the weakest link. They eliminated the narrow part of the shaft, but those aftermarket are hardened aircraft steel and everything else!
 
#23 ·
The way it was explained to me was that this was caused from WOT 4th gear pulls and probably WOT 3-4 shifts.
 
#25 ·
Well, transmissions get better and better. The truck we take around the country is a 2002 Cummins diesel with over 400,000 miles and we just had to have a band replaced that looked very similar to the one in the above photos!

I understand why they need the bands and if there is a better way, I'm sure we'll be seeing it soon!
 
#26 ·
i did the WOT 3->4 one time with my old F5 trans that was slowly dying. never again.... the sliiiiiide into gear, and the OD light flashing made my heart stop :D

kept going for a while till the TC shrapnel'd out and i couldn't get it to stay running at stoplights or in any other gear but park, and neutral... neutral bombed my way home and parked her till my Mk8 F7 went in :)
 
#28 ·
So what happens if you need 4th gear for the quarter mile? I haven't taken the new engine up to that kind of speed yet but I remember my running real high in the RPM's at the end of the quarter mile in 3rd gear with the old 2v. What if you run a 4.30 or a 4.56 gear and you need 4th gear? Manual is the only way to go?
 
#29 ·
If you've got a 7000 RPM redline with 4.88s, your top speed can be as high as 120 MPH in 3rd gear with a 28" tire. If you've got a 4.56, that becomes 128 MPH. With 4.30s, that's 135 MPH, and 4.10s that's 142 MPH. With a 27" tire that's 115/123/130/137 MPH.

To cross the line at speeds like that you'll probably be running at least 11s...
 
#34 ·
Thats fine if you rev to 7000 RPM but what if you don't? Granted, most 4.6 MN12's (especially N/A) are going to have extensive top end work to help them make the power they need to run that fast thus they may have a 7000 RPM redline. But what about a car without that top end work.

Lets take a MN12 with a PI swap with a Vortech plus supporting mods (fuel, water/meth, bullet intake etc.) running stock long block at 13psi and weight reduction (lets say 3300 lbs). That engine should still see peak power around 5800.

So at 5800 RPM with 4.10's in direct drive and 255/60-15's the car would max at 114 MPH and about 102mph with 4.56's. That car should easily have the power to run 114 MPH in the quarter

I am not trying to question your logic or anything I am just curious as to what can be done to the trans to allow shifting into O/D at WOT without damaging the trans.
 
#32 ·
+1

Seriously. Just make more power. I wouldn't want more than a 4.10 in anything.
 
#35 ·
Well, yes. WOT means foot to the floor. This condition includes when shifting and when in OD.
 
This post has been deleted
#45 ·
#41 ·
#43 · (Edited by Moderator)
Yeah its synchronous brand. The under drives are all non-synchronous meaning they only need the next brand to apply where as synchronous needs one to disengage and they other to engage at the same time. I see now.

Correct me if I'm wrong...But since WOT passes in OD are a no-no..

Swapping the 4R70W Gear Set out for the AOD-E Gear Set should lower your RPMs in 3rd..

How much lower just depends on how much Rear Gear you have now??

:cool:

Rayo..
No it wont because AODE like the 4R70W have a 1.00:1 3rd gear ratio.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top