Duramax Allison issue
 

Decided to change the screw on external transmission filter during other maintenance work on my 2018 3500 Duramax.
Purchased a well know house brand replacement filter . Immediately experienced down shifting problems. Purchased a GM filter from the dealer @ a 34.00 cost.
Problems ended. Going to purchase a couple of more for inventory.

Be aware if you have late model Duramax tow rig.

Steve Teeter. STK 6380/6283

Re: Duramax Allison issue
 

We have some service trucks with Allison transmissions.
Was told to run nothing but the OEM filters in them.
No issues doing this, but I haven't tried anything else.

Re: Duramax Allison issue
 

Thank you very much for the heads-up!

Re: Duramax Allison issue
 

I personally think the aftermarket shouldn’t produce any type of filter for a duramax or Allison . Fuel filters are the big deal most house brand fuel filters won’t pull moisture out of the fuel causing massive damage to the direct injection pumps, the Allison trans is a great example of you better have the sense to service often or else.....

Re: Duramax Allison issue
 

Thought I was buying a high quality filter brand. No Fram stuff. Micro size of the filter is obviously critical to the Allison transmission flow requirements.
Difficult to understand how a major filter manufacture had not done any engineering on the flow rate required on a replacement filter they are selling.
Seems to me they are opening themselves up to a class action law suit.

Steve Teeter. STK 6380/6283.

Re: Duramax Allison issue
 

Same for the fluid you use. Allison has recommendations and approved products on their site.

Re: Duramax Allison issue
 

This is interesting ! Did you change the Fluid when you put the aftermarket filter in ? What happened when you say you had down shifting problems ? Did the problems go away immediately when you installed the GM filter ?

Re: Duramax Allison issue
 

No I did not change transmission fluid. I did add additional Dex Vl after changing filters. I did use this same manufacturers filter in my 2012 3500 Durmax/Allison with no issues. After changing filters on my 2018 , when i was off the throttle , coming up to a stop light, it would bang hard when it down shifted into 1st gear. Up shifts under power , no issues. Only downshifting.
It's all I changed ( other than engine oil and filter ). I purchased and installed the GM OEM filter, added addition Dex Vl and the downshifting issue has not happened since

Hope this saves other Racers some headaches

Steve Teeter STK. -380/6283.

Re: Duramax Allison issue
 

I don't know much about the Duramax Allison, but I've needed to service both the Allison 3000 & Allison 4000.
When Allison switched from Dextron ATF type fluids to their Transynd fluid, I noticed the stuff is very thick and probably won't flow through most standard transmission filters.
Kind of an odd type fluid, but if you regularly maintain the 3000 & 4000, they are literally indestructible. Kind of need to do what they say.

Loren

Re: Duramax Allison issue
 

YIt's a Allison trans not a GM design and manufactured trans!