Dealer changes transmission inner filter!!?

[billsMax]

Tuesday I dropped 2001 3500 duramax with 24000 miles off at dealer for checkup. Told him I'm getting ready to leave for Alaska and want the 25,000 service a little early. Told him I wanted transmission fluid and filter changed in addition to other stuff. He stated that they flush transmission and replace internal filter. Told him NO, don't replace internal filter, only replace external trnmssn filter.
When I called later in the day to see if truck ready, service manager says they didn't have correct fitting to flush Allison trnmsn but they were almost thru replacing internal filter. I again told him that wasn't supposed to be replcd, only the external one. He didn't charge for internal but my question is.....They know so little about the Allison, should I be worried they may have screwed up something in the trnmission? It is driving find and no leaks.

I hate OJT on a $40,000 truck.

[DmaxMaverick]

Guess you really can't teach an old dog new tricks. Better get down there and start digging through their dumpster for your tranny filter magnet! I wonder if they replaced the pan gasket as well. It is reusable. Some of these dealers really crack me up!

[DMAXDiva]

BillsMax:

I spoke directly to Allison regarding the tranny filter change recommendations yesterday. According to tech services, spin-on filter only should be changed at 5k, then full flush/internal filter change at 25k miles. I had my truck in for 5k service this morning (rear differential fluid change, oil change, etc.) and the service writer looked at me as if I had two heads when I told him to change the spin-on filter on the Allison. He went on and on about the service manual's tranny filter recommendations of first change at 25,ooo blah, blah, blah...even went so far as to say I was wasting my money by requesting it. Well, needless to say, the truck now has a new spin-on filter, and the service writer has a freshly-adjusted attitude!

Anyway, to get back to your original question...yes, Allison does recommend internal filter/screen change at 25k miles. Hope this helps!

[77TransAm]

I don't know who from Allison gave you the info, but according to the 1000/2000/2400 series Mechanic's Tip, Service Manual, and other literature, the suction filter is only replaced at overhaul. The change intervals you list are correct for the spin-on filter, however.

[D-n-Tyke]

So at these 5,000 mile chenges are you suppose to drain and refill the trans fluid too? Or just spin-off old filter, spin-on new filter, top off fluid? :confused:

[walkerkd]

change fluid and spin on filter. thats it. do not! i repeat do not flush the alli!!! that is a no no...the service guys ive talked to at the gm dealer dont even recomend anything until 25k wth!!! allison on thier web sight and the shop i use both say the same thing. 5000 miles!!!!

http://www.allisontransmission.com/documents/product/publications/pubs/MT3190EN.pdf

[mdrag]

BigAl has indicated in previous threads the recommendation to change ONLY the spin-on filter at 5K miles - no need to drain/refill the tranny at that time - just add enough ATF to make up for the small amount that is lost during the spin on change. Drain/refill of the ATF at 5K will not cause any problems, but isn't required.

Unless Allison had a recent change in their recommendations for the internal filter, it was to be changed at tranny overhaul as pointed out by 77TransAm. Also, the internal filter will need changing if switching to the deep trans pan.

Moving topic to 2500HD/3500 HD Trucks & Drivetrain forum.

[DmaxMaverick]

I flushed mine when I switched it to Amsoil synthetic ATF. It was easy. I removed the "from cooler" line and let the tranny pump the fluid out (engine idling) while I added more to the pan. Piece of cake and no problems.

[hoot]

Replacing the internal filter is a waste of time and money. It's not really a filter. I know. I had mine out when I went to the deep pan. It's only a fine mesh screen. It has a large area so it's unlikely that it would ever get clogged. I would think the spin on does all the work. The internal is only to keep the big pieces out of the intake tube.

[GMFAN70]

I think we should emphasize to D-n-Tyke that 5000 mi. applies only to the first filter change, not to subsequent changes.

[BOOMERHD]

hey dmaxmaverick,
where was your thread on that flush job you did? I remember it from quite a few months ago, and now i'm @ 25k miles, and was going to try it with the AMSOIL, but it seemed to be a two person job trying to fill while draining and such.

[TURBOJOE]

"hoot Replacing the internal filter is a waste of time and money. It's not really a filter. I know. I had mine out when I went to the deep pan. It's only a fine mesh screen. It has a large area so it's unlikely that it would ever get clogged. I would think the spin on does all the work. The internal is only to keep the big pieces out of the intake tube "


Hoot is right on the money. Only way that the internal filter will ever get clogged is if the trans blows and needs an overhaul. That's the only time Allison recommends changing it. That's what I was told when I talked to a Allison service writer when buying the filters(spin on). ;)

[DmaxMaverick]

BOOMERHD

I couldn't find the post either.

You can do it alone. I did. It's not difficult or complicated (unless you make it that way). Help is always good (almost), and would make it easier.
Start with a drain/fill like you normally do, but wait until last to change the filter (don't forget the magnet!).
I had the use of a pit (a friend runs one of those "quicky lube" places), so watching and filling was no prob. It will pump out a little slower than you can pour it in (make sure it is at operating temp. so your idle is lowest). I overlapped by 4 qts, just to be sure I got as much of the old stuff out as I could. You can get about 4 qts. low before it starts to suck some air, so unless you crawl, the timing isn't a real factor. It did take about 2 days and 300 miles for the fluid level to stabilize. I think I got some air into it, but it seemed to have no effect on performance. The flush job took less than an hour to do solo.

I made a 500 mile trip this weekend with my 12K 5'ver, which included four 6% plus grades (each way) that I towed before. The tranny temp. was 2 lines lower on the gage (whatever that translates to) than the 2 previous trips on the same route. A definite noticeable improvement! It was warm enough out for the rad. fan to run about 1/3rd the way up most. It also seemed to shift smoother and more consistently. I did notice that it takes a bit longer to warm up, though. I am very pleased, so far. Good luck with it, and IMO, Amsoil is a good choice.