best way to test for Allison damage?

[Boost]

What are some simple and clear tests I can do to determine / convince someone they need to build trans?

Please don't take this question the wrong way, I need to relay this info to an alleged Allison builder that is giving my customer contradictory info.

The truck is an 06 LLY with high mileage. It shifted sloppier than usual on the stock test drive, and when a good 100 hp tune was flashed it slipped bad and did not learn in several days. He took it to a shady trans. shop and they told him there was no need to overhaul it and also that the "special code from the trans. was not removed by the tuner to enable the engine tune" - not going to comment on that LMMFAO...

Not sure if they mean TAPS or TCM tuning but neither applies to this... anyway,

Common sense tells me the trans. is old and worn and he needs to upgrade the TC and clutches or better have a COMPETENT tech install a fully built unit.

What definitive diagnostic tests can we perform to silence the guy that says a 150k mile truck that can't hold a known good 400 hp tune and is slower stock than other similar trucks doesn't need tranny work?

I am thinking maybe

-monitor slip PID
-look for P7xx codes or limp
-send oil sample to lab??
-stall test???
-anything else????

THANKS!

[THEFERMANATOR]

Drop the pan and check for clutch material. Change the spin on filter and cut the old one open and look for clutch material. Also see if it shudders during lock-up, or if it won't hold lock-up. A 150K mile trans shouldn't need built to hold a 400RWHP tune unless it has been run tuned for awhile in which case it is probably due. They will hold 400RWHP for awhile, but nowhere near as long as they will run stock. Also being an 06 there is a good chance that the factory used DEXRON VI fluid has eaten up the old style trans seals. ALLISON didn't start using DEX VI compatible seals until mid year 06, while GM began using DEX VI in late 05 for the 06 MY(although ALLISON did factory fil lthem with DEX 3 when they were built, but GM did top them off with DEX VI when they were installed into the trucks).

[Boost]

Thanks for your reply.


Drop the pan and check for clutch material. Change the spin on filter and cut the old one open and look for clutch material.

How can I tell clutch material from the normal metal cream that is usually on the drain plug of these?


A 150K mile trans shouldn't need built to hold a 400RWHP tune unless it has been run tuned for awhile in which case it is probably due. They will hold 400RWHP for awhile, but nowhere near as long as they will run stock.

That's just the thing, we don't know it's history, it appears stock but most trucks around here HAVE been tuned early in their life and set back stock when sold / traded in. This truck needs to be able to hold 400 rwhp all day in addition to light / moderate towing. Any weakness in the tranny is unnaceptable. These days are not the same like when I went 0-40k miles on my truck at 450 rwhp without a hiccup. Most trucks are over 100k with history, and the customers are expecting the trans. to hold like new with a big tune.


Also being an 06 there is a good chance that the factory used DEXRON VI fluid has eaten up the old style trans seals. ALLISON didn't start using DEX VI compatible seals until mid year 06, while GM began using DEX VI in late 05 for the 06 MY(although ALLISON did factory fil lthem with DEX 3 when they were built, but GM did top them off with DEX VI when they were installed into the trucks).

Is this a common issue? The truck doesn't seem to leak or burn fluid. I thought VI was just way better all around. How can we confirm if this is even an issue here?

Thanks!

[THEFERMANATOR]

Thanks for your reply.



How can I tell clutch material from the normal metal cream that is usually on the drain plug of these?


There shouldn't be but a slight metal cream on the filter magnet. Any signs of black clutch material in the pan is bad news though. Also check to see what the trans temps are running, and give Mike L a call. If you can get ahold of a TECH2 he can tell you how to interpret the TAPS info to tell you wether or not the clutches are holding or if they aren't doing well.

That's just the thing, we don't know it's history, it appears stock but most trucks around here HAVE been tuned early in their life and set back stock when sold / traded in. This truck needs to be able to hold 400 rwhp all day in addition to light / moderate towing. Any weakness in the tranny is unnaceptable. These days are not the same like when I went 0-40k miles on my truck at 450 rwhp without a hiccup. Most trucks are over 100k with history, and the customers are expecting the trans. to hold like new with a big tune.

If you only want to hold 400RWHP and tow with it though, a stock build with stock clutches, TRANSTAR single disc billet cover converter, lockup boost valve, and a main pressure spring would suffice. But for an extra $1500 you could build it to hold pretty much anything he may want to throw at it down the road.



Is this a common issue? The truck doesn't seem to leak or burn fluid. I thought VI was just way better all around. How can we confirm if this is even an issue here?

Thanks!

DEXRON VI isn't worth using to flush your toilet with according to one of the best known ALLISON gurus out there. If the trans has been serviced by the dealer, then yes there is a chance it is experiencing internal seal leakage. ALLISON even released a bulletin about it in 06 that they did not approve of the use of DEXRON VI in there transmissions until the ones built mid year 06 came out with the revised seals in them. And they would not warranty any trans that had used DEXRON VI fluid in it. GM of course ignored it and used it anyways to top them off at the factory. And if it was dealer serviced then the ratio of DEX VI to DEX 3 got to where it would dry the seals out and cause leaks. This is a well knwon problem on 5 speeds that get dealer flushed, and about 6 months later start pouring out oil from the shift shaft and front pump seal.

[Boost]

Wow did not know that about Dex. VI, in GM training they teach us that is is 50% better at protecting from heat and breakdown and such than Dex III. They highly recommend it as top of the line stuff. What would you use instead? Allison fluid or maybe Amsoil? And I am assuming for LBZ and up it is still good, since they are still filling and servicing new ones with it. I have been out of the loop but I have never heard of such problems, is the TSB# available?

So other than looking for black stuff, is there a diagnostic test I can do with EFILive Scan Tool to confirm a slipping tranny with a mild tow tune? Maybe something with the input / output shaft speed sensor PIDs or Calculated Slip? Can I pull the current TAPs?

Thanks again!

[THEFERMANATOR]

You can watch the slip % with EFILIVE, but I don't know if it will show you the TAPS and max torque input or not like a TECH 2 will. GM thinks DEX VI is the greatest, but it has alot of drawbacks to. Ask GM what happens to DEX VI below -40 F out and see if tehy will fess up the fact that it waxes over and plugs up coolers which has killed many an ALLISON up north. I don't have the link anymore, but ALLISON has it on there website about not using DEX VI, and to only use a TES-295 fluid(TRANSYND) or the older TES-389(DEX 3 type fluid). I use CASTROL DEX/MERC fluid myself, but for a stock trans with stock clutches it is hard to beat TRANSYND. CITGO QUATRASYN is another good fluid that is DEX/MERC compatible as well as TES-295 approved.

[Boost]

Excellent info, I appreciate it THEFERMANATOR! :)