Custom LMM & Allison in Patrol - flare from 4th to 5th

[Gutruk]

G'day all from Australia , just after a bit of advice where to start looking for my Allison please. Trans rebuilt a few years back with stage 5 kit, shift kit, triple disc TC. Engine is slightly tuned with 30 overs and bigger Turbo etc and custom tunes. It been running sweet since rebuild (probably 40K miles in your speak) recently its been flaring a bit 4th to 5th only, light throttle its like a hiccup, more throttle it become like a flare. No thumps bangs or otherwise. Changing down is fine and no codes at all on Flashscan.
In tow mode it will do it also and is more pronounced, it wont happen all the time in tow mode but is getting more frequent.
Same TCM tune I have had for ages and it has the converter lock up on shift enabled.
Oil and spin on filter cut/examine were spotless and no overheating at all.
Wiring connector at rear is clean and not leaking.
Appreciate any tips for me to start looking thanks in advance!

 

[Mike L.]

What kit was used in the Allison? What other mods in the trans?

 

[Gutruk]

What kit was used in the Allison? What other mods in the trans?

G'day it was a PPE stage 5 kit and so I have just worked out it does not have a shift kit in the valve body thats in it now. As we replaced the valve body due to a crack early in its life and the shift kit (Transgo Jnr) was never transferred across. I am thinking I need to get a shift kit into it do you agree?
Other mods are custom output shaft and thats about it.

 

[Mike L.]

Try the shift kit. I can send you one with my custom springs. Problem may be that you don't have my pressure regulator spring for increased pressure. You may have hurt the clutches as the PPE kit leaves a lot to be desired. Call me at the shop

 

[Gutruk]

Ok I will try it thanks, I recall we did update the pressure regulator for increased pressure during original rebuild. As the increased line pressure then increased a pre existing issue of bleeding some oil pressure into C5. Which was found to the the fractured valve body, we never did "find" the crack but a replacement valve body corrected the C5 issue at that time. It has been trouble free since then up until now with the slight shift issue.
I am keen to try your custom springs however I am in Queensland Australia so it may take some time to arrange it?
I can try and call a bit later thanks.

 

[Mike L.]

Ok I will try it thanks, I recall we did update the pressure regulator for increased pressure during original rebuild. As the increased line pressure then increased a pre existing issue of bleeding some oil pressure into C5. Which was found to the the fractured valve body, we never did "find" the crack but a replacement valve body corrected the C5 issue at that time. It has been trouble free since then up until now with the slight shift issue.
I am keen to try your custom springs however I am in Queensland Australia so it may take some time to arrange it?
I can try and call a bit later thanks.

Something doesn't sound right . Valve bodies don't fracture.

 

[Gutruk]

Something doesn't sound right . Valve bodies don't fracture.

I agree, however this Engine and Transmission were from a donor in the USA (possibly out of wreck) and it appears the pan had been replaced but there was evidence of impact on one corner of the valve that we didnt pick up until replacing it and a very close inspection afterwards. The replacement valve body resolved the C5 melting issue I had back then so we suspected a fracture of some sort internally.
So thats how I worked out I have been running without a shift kit, as the one we installed was in the valve body we replaced. Further investigation into the valve body I used reveals it was just a standard one (whereas I originally thought it had a shift kit in it as well).
Therefore I have been running for 40K with no shift kit in the valve body but a main system pressure increase.

 

[Gutruk]

I agree, however this Engine and Transmission were from a donor in the USA (possibly out of wreck) and it appears the pan had been replaced but there was evidence of impact on one corner of the valve that we didnt pick up until replacing it and a very close inspection afterwards. The replacement valve body resolved the C5 melting issue I had back then so we suspected a fracture of some sort internally.
So thats how I worked out I have been running without a shift kit, as the one we installed was in the valve body we replaced. Further investigation into the valve body I used reveals it was just a standard one (whereas I originally thought it had a shift kit in it as well).
Therefore I have been running for 40K with no shift kit in the valve body but a main system pressure increase.

Hi, just some feedback on this one. I pulled the valve body on weekend and fitted all new solenoids (old ones all tested ok), new harness and new pressure control valve. Also installed the Transgo jnr kit. The pan filter was spotless and I cut the spin on filter, it was also spotless no material or metal at all (done 40K KLMS).
I refitted it all, reset all the TAPS via EFI live and went for some runs. It shifted sweet from the start and still is. No flares and shifts are more solid, I let it learn for awhile then gave it some WOT runs. Still no issues and shifting very sweet!
Appreciate the feedback and advice thanks!