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!

Re: Duramax Allison issue
 

Switching to the Transynd fluid or as I did Delvac approved fluid the transmission is smoother. If you tow heavy you might consider using the better syn fluid.

Re: Duramax Allison issue
 

Allison was part of GM Hydramatic when the 1000 was developed . The Engineers from Indy work side by side with us in Ypsilanti . When GM went through bankruptcy Allison was spun off but the only Allison trans that remained with GM was the 1000 because it was in most of the 1-ton pickups . I think it's still built in Baltimore . Also Castrol developed the fully synthetic fluid Trans-Max , and later Allison re-named it Trans-Syn . It is a very good Automatic Transmission Fluid

Re: Duramax Allison issue
 

Would the Trans Syn fluid be better in a 2001 1000 model Allison than the Dexron?

Re: Duramax Allison issue
 

Yes! My 2003 has it. Smoother and less trans temp. Walmart is the best deal on approved Delvac Allison syn. I don’t use Castrol...

Re: Duramax Allison issue
 

Summit's price was the best I found, never checked Wallmart.
Yes trans shifts smoother & runs cooler.

Re: Duramax Allison issue
 

Works so well in the truck I’m tempted to try it in the race car.

Re: Duramax Allison issue
 

I've used Transynd in Powerglides behind some big HP in an attempt to get better pump life when the pressure gets over 225 psi and it definitely seems to help. It is a full synthetic and a higher viscosity than regular Dex 3 fluid. Castrol was the original supplier when Allison wrote the specs for the fluid, TES-295. They have since added a few suppliers to the approved list. As far as what to use in an Allison, I wouldn't use anything that they haven't approved to TES-295.

Jim Mantle V/SA 6632

Re: Duramax Allison issue
 

Allison part #. Change every other oil change. Deep pan and Transynd 30k. Transynd doubles the service life in conjunction with additional ATF (deep pan). Don't forget to take the magnet out of the old filter, to put in the new filter.

https://i.imgur.com/jKFkkcC.jpg