Allison Slippage

[CHILLINONTHERIVER]

I have an 04.5 LLY (50K Miles) with a Juice w Attitude and have noticed slippage in the tranny. I have never monitored it before until recently when it became obvious that the shifts were lazy and not very responsive as it used to be. I have started to monitor more recently and noticed it slips in 2nd, 3rd and 4th gear about 40% and up to 69% at heavy throttle on level 3. If I go to tow mode it locks up but still slips (4th and 5th gear) 5% to 8% under heavy throttle. OK, so the question is, I see it slipping, is this excessive slippage and if so do the dealers have something that they can see the slippage as well when they drive it. I have taken it in to get the tranny filter and fluid changed and mentioned that it seemed to be slipping but they say it is fine. I have to take out the Edge to get it serviced so how do I get them to see it without telling them that I see it on my Edge? Truck is used to tow a 32 Weekend Warrior about 4 times a year and a 16' flat bed with light loads once every couple months. Truck is mainly used for local/highway driving. I do hot rod it at times so I am suspecting the torque converter is toasted but again how do I get the dealer to acknowledge there is a problem. Also, being the truck is at 50K miles, would this be covered under warranty. Anyone in BUllhead City , Az that does the high performance Trannies? Thanks in advance for any responses.

[More Power]

What was the condition of the ATF when you changed the fluid? Darker - smell burnt?

If the fluid was OK and you're not seeing the trans going into limp mode, it may be a bit too early to worry about things. The ECM/TCM will pull fuel during upshifts, and which becomes a lot more noticeable when increasing power.

Jim

[cowboywildbill]

Correct me if I'm wrong, but if your not in tow haul mode then what you may be seeing as slip could just be the torque convertor doing it's thing when not locked up. I think Jim nailed it when he said to check the condition of the fluid.
Also see what is on the magnet on the spin on. Let us know what you find out.

[CHILLINONTHERIVER]

I just had the dealer do the fluid flush and filter change when I mentioned to them about the slippage, or at least I think its slipping. They indicated that the fluid looked ok they could not find anything wrong. They indicated there was nothing on the magnet (I asked), that was something I had read on the forum. Truck just seems lazy at shifts and then I can watch the slippage. Appreciate the responses guys.

[More Power]

I'm putting the finishing touches on a new article about ATS Allison performance transmissions. In this article are two dyno graphs produced by a truck (my 2001) with a stock Allison - one graph at stock power and another with an additional 140 hp. You can see a dramatic difference between the two runs in how much fuel is being pulled between shifts when using stock power and another with more power than the Allison can handle (during a shift). The trans didn't limp. :)

Jim

[CHILLINONTHERIVER]

So are you saying that it is pulling more fuel out during shifts with the extra 140 HP? Is this in tow mode or w/out tow mode? Is the ATS Allison performance transmissions something that you suggest?

[77TransAm]

Chillin', keep in mind that the Allison TCM continuously monitors the input speed, turbine speed, and output speed, and if there is any slippage, it should be detected immediately. This will set an SES light, and store an Incorrect Ratio code in the TCM.

Unless your Edge somehow disables this function, you should have a code and a light if your transmission is actually slipping.

[CHILLINONTHERIVER]

Update:
While driving home from work this morning, doing about 65 in 5th gear torque converter locked, attitude @ 3, not in tow mode, I punched it to pass someone and it fell on its face. It went 3rd or 4th gear would not shift up anymore, engine light came on, I guess you guys call it limping? Lucky for me I carry my predator so I was able to retrieve all codes, which I will list below and clear them to continue to get home.

Codes
PO101 Mass air flow malfunction
PO401 EGR Flow Malfunction
PO404 EGR Circuit
PO700 TCM Malfunction
PO1223 Unknown
PO1229 "
PO1232 "
PO1235 "
PO1238 "
PO1241 "
PO1244 "

Anybody seen this before. Also, I realized that I have the boos stick from Kennedy and running on 3. I think I remember reading that running on 3 could be too much so I have dropped to 2 and not had any problems but shifts still seem lazy. Comments?

Thanks

[More Power]

During a full pedal run using stock power and stock Allison, power dropped to ~160 hp during the 2-3 upshift and 185 hp during the 3-4 upshift. Max power for this run was ~265.

During a full pedal run using an additional ~140 hp (DSG Van Aaken) with the stock Allison, power dropped to just 55 hp at the 2-3 upshift and 115 hp at the 3-4 upshift. Once the shift had been completed, max power rose to more than 410 hp. Lots of fuel was being pulled to allow the Allison to complete its shift.

I believe the ATS Allison is as good as any performance transmission by itself, and the Co-Pilot in-cab controller adds several benefits that others don't. The end result is very little fuel reduction during a shift while at the track, but it still shifts nice when driven to the grocery store.

Jim