Goerend triple disc TQ

[Jays0624v]

I had my 48re rebuild a few years ago with Goerend triple disc TQ I belive its 15 SS. I started to tow my fith wheel recently and noticed when the truck shifts from 3rd to 4th under a load there's a weird sound that comes from the turbo. Can someone tell me if this is normal. And will the triple disc cause this noise. Not sure if it's my stall speed. Any advice or information is much appreciated. The truck is an 06 DRW with 410, I have a banks air intake and exhaust brake. Not sure if that matters but thought I'd let you know.

 

[SnoKing]

Woof??? https://www.turbodieselregister.com/threads/turbo-sneezeing-or-woofing.1141/

 

[cerberusiam]

If it sounds like a propane burner lighting off under the passenger floorboards, that is turbo bark. More accurately it is compressor stall cause but the big jump from 3rd to 4th and a triple disk's tendency to not unlock on a 3-4 shift.

Stall speed is only applicable in fluid coupling, has no effect once the TC locks.

 

[Jays0624v]

Woof??? https://www.turbodieselregister.com/threads/turbo-sneezeing-or-woofing.1141/

Yes that's the sound

 

[Jays0624v]

If it sounds like a propane burner lighting off under the passenger floorboards, that is turbo bark. More accurately it is compressor stall cause but the big jump from 3rd to 4th and a triple disk's tendency to not unlock on a 3-4 shift.

Stall speed is only applicable in fluid coupling, has no effect once the TC locks.

Going to a stock air box and stock exhaust make a difference ?

 

[cerberusiam]

No, it is the TC and not unlocking on the 3-4 shift that is causing it and that is all in programming. About all you can do is get a feel for when it wants to shift to OD and lift off the throttle a bit so you don't have a lot of exhaust flow that drops suddenly, or, manually shift to OD when you are up to speed and off throttle.

What is happening is the exhaust flow is dropping because of the big RPM drop and fueling cut from 3 to 4, the flow won't support the turbo speed so it literally stalls the turbo compressor because boost is suddenly greater than drive pressure. If you could tune the 3-4 shift to unlock completely, shift 3-4 and keep rpms up, then lockup the TC when things balance out it won't happen. The 3-4 lockup strategy pulses the unlock and expects a single disk that will unlock enough to do that, but, a triple disk will not unlock on a TCC pulse off. Not enough time to get it to happen unless the pulse width is lengthened. There is a possibility that custom trans tuning can address that, have not aske the authors whether that specific PID is exposed and they can adjust it. The 48RE transmission controls are kind of crude and they are not exposed or documented well.

 

[bigceltic]

Yes that's the sound

I put in a BD Turbo Guard (blow off valve) to stop turbo "bark" - I only had the issue when I was pulling/towing hard up a mountain pass and someone (trying to be nice here) would cut me off, causing me to have to get off the throttle fast, causing a "bark".

 

[Sled Dog]

Why Not, call Dave Goerend.
That's what I'd do........
He Know's Jack Schitt
JMHO........
I Know For A Fact,
HE Wants You SATISFIED!

 

[SSage]

I pull up to 18K with stock intake and exhaust, it will bark sometimes when the TC locks up and I forget to back off a little. Back off the throttle a little at 45 mph in OD and it should lock up like butter. You can also stay in 3rd till 50 mph then shift to 4th when pulling hard. I do that to be easy on the driveline, hard lock ups under major boost and loads will shorten component lifespans. The TC can take it though, its the stock input shafts or drive shafts that can complain first!