Allison Trans overall performance

[chrisinkanata]

My '02 has about 30k miles now in about 16 months. Absolutely no trans issues so far. Our trailer weighs about 8000lbs and we tow probably 10,000mi/yr. I'm wondering if overall, any one is aware of any issues with the trans. It seems that injectors are a bit of an issue on the 6.6. Is there anything like that in the Allison? I see no real long term problems in searching the forum but if anyone has any insight, it would be appreciated.

Thanks,

Chris

[403turbo]

Nope the Alli is overall a great setup.

It seems that a batch of them got loose from the factory with the torque convertors not properly torqued(ironic isn't it) That caused some TC to crack and seriously leak (mine did). But that seems to be a very rare problem. Other than that no consistent problems or weakness in stock trim.

If you add power you need to become more of an expert because you can hurt it.

There are plenty of threads about Tranny upgrades here.

Keep the filter changed and fluid in good shape and it should outlast the rest of the truck....except maybe the motor smile.gif

[hd90rider]

265k miles on mine,towing 70% of the time. "Knock on wood " never a problem with the Trans. Truck is stock.

[sonofagun]

Chris,

Rock solid. Allisons usually come with a bigger (deeper) pan but GM was concerned about clearance issues. I put the deeper pan on mine and have had no clearance problems on or off road. More trans fluid might reduce heat which might extend trans life. The modification is cheap and easy to install.

Regards,
Bob

[TFEnt]

I have a different opinion after tearing my Allison apart after 4,000 miles.

I bought my 4th Duramax in June of 2003. I only had a problem with one of them that GM took care of in a very timely manner. My Duramax is used to tow my 96 Impala SS SEMA Show car. I tow the car in a 26 foot enclosed trailer that when loaded weights 12,000lbs.

I broke the new D-max in and at 450 miles hooked the trailer up and towed it from San Diego, Ca to Tulsa, OK and back for a car show. When I returned I took the vehicle with now 4,000 miles on it up to The Trans Shop in El Monte, Ca owned by a gentleman by the name of Marvin. Trans-go is one of my car sponsors and sent me there to get the new Trans-Go Allison shift kit installed. This involved removal of the transmission.

After Marvin removed the tranny it was inspected and we found that the second gear clutches in the clutch pack were already starting to burn up. This clutch pack along with another set of gears makes 5th gear in the Allison. This means the whole trip in 5th gear those clutches were slipping. So an Allison rebuild kit was installed with the new Trans-Go shift kit. In addition to that we had Terry from Precision Industries build us a new triple-plated billet torque converter. All was reassembled and we set out for another test tow. This time to Dallas/Ft Worth for another Car Show.

I returned a couple of weeks later and with 3,500 more miles on the truck and new tranny. The transmission was again disassembled and inspected. Not to my surprise, but this time there was no sign of any slipping to the second gear clutches. In addition to that it was noted that the tranny shifted WAY better and ran cooler during this trip then ANY other towing trip I have taking in a Duramax.

In addition I must also state that I used the Hypertech Programmer in stage 2 or 3 for all testing.

Trans-Go claims that the shift kit will upgrade the tranny to withstand more than 500 hp alone and 900 hp with shift kit and torque converter.

Yes, Trans-go sponsored the parts and installation for this test. The torque converter was paid for out of pocket. This doesn

[MAD-MAX]

I thought that the Allison could tell if it was slipping in 5th gear and go into the limp mode!!!!

[airtime]

SSmokeybear,
I've heard alot about the Trans-go kits, you seem to know, so here goes. In T/H mode, mine shutters between 2nd and 3rd. Out of T/H mode it shutters going in to overdrive/5th gear, this happens usually off throttle. It's been to GM 4 times, and Allison once. NOBODY could find a problem. They flushed it with Syntec and it got better, but didn't go away. Slipping clutches, or a leaking torque converter? My guess is the former. Of course I'm out of warranty, and just now put on a lift kit with O/S tires!
Odd man out with an 8.1, It smokes my 35's!
AT-