there is no need to use a second filter. the small amount of material you pickup in the filter between the two pan drops is not going to significantly shorten the life of the filter. especially if you are doing the maintenance as often as you should instead of as recommended by GM. that said, if putting a 10$ filter in there the second time makes you feel like your treating the truck better, 10$ is not that much for a little extra peace of mind. When you factor in the cost of the relatively clean fluid your dumping on the second pan drop, the filter is really not even a factor.

 

Are you changing it over to synthetic?

 

Goood point on the money that just gets flushed out when doing the double drain. That’s basically $50 that is only used for 100 miles. What is the diffence if I use 2 filters and through away $60...haha

I use Mobile Delvac ATF which is synthetic. I changed to it at 50k miles (after changing original fluid with Dex 6 at 30k miles) with a triple change (yes probably over kill) and now I’m at 125k miles. I believe they say it is good for 100k miles with synthetic fluid but I always change fluids early. Helps me feel better about myself. I change the filter every 3 oil changes so that equals about 15-18k miles on the filter.

 

Mobile Delvac is a TES 295 fluid approved by Allison. It is directly compatible with Transynd. I just recently did the double drain to switch over to Transynd. I found it at $35 a gallon at th e nearby Allison Parts/Repair dealer. Mobile was at $50 at the local parts houses.

Here is a list of the Allison approved TES 295 fluids:

On-Highway Fluids

Like you I like to change fluids early, not late. My schedule is all based on multiples of 5000:

5000 = Engine oil and filter, lube front end
10000 = LP Filters and Spin on Allison Filter
20000 = Tertiary fuel filter
50000 = Transmission fluid (already did the double drain so single drain is sufficient), Differential fluid and Coolant
2 years = Brake fluid and PS/HB fluid

I find that schedule easy to keep track of and well within the approved time intervals.

 

I just changed the spin on filter on the 2nd drain.

 

I think your wasting time and $ why not change filter about ever 20,000 miles and oil every 100,000 unless your doing severe duty, read the allison service interval and your more than fine, the double drain in a 100 miles is ( JMHO) silly!

 

Drive 100 miles between changing fluids for the double drain. Not every 100 miles.....and yes I do tow 10k pounds fairly often. Doing the double drain on fluid at 75k miles.

 

I have to order everything. Never found Transynd or Mobile ATF at any shop around here. Went to one Kenmore shop and they wanted $55 a gallon for Transynd. I don’t order stuff like this from Amazon because I dont want fake stuff (yes I have received fake parts before). I got 4 gallons of Mobile ATF for $160+$17 shipping.

Only 1 place I know of around me that sells Transynd and that is DMaxStore but they are 40 miles away from me. Great guys been there before but still $100 for 2 gallons and a filter so more expensive then ordering fluid and filters separately

 

Not sure where you are but there is an Allison service/parts center in both Modesto and Oakdale, CA

But honestly at $160 for 4 gallons that is only $20 more than I spent. From now on you will only need to do a single drain so 2 gallons only.

 

I thought the double drain was for changing types of trans fluid such as when you switch from bio to synthetic. That is so you will not have 2 types of fluid in there at the same time.

Double should not be necessary for same type fluid change. Especially since you are within time/mileage limits of additive package for the old fluid. Filters are cleaning the fluid, new fluid is basically refreshing additive package.

You are really wasting a lot of beer money with a double drain and staying with the same type fluid for regular maintenance. The Allison/GM (?) engineer on here mentions it in his post. So, what he says. The guy that wrote the fluid specs for many transmissions and did it everyday for decades. I'm hard headed, but I believe him.

 

Precisely correct..................

I just cannot attest to how hard you head is................I can only say mine is right up there *S*

 

Guess I will only do a single drain and will have a bunch of fluid left for next time...from what you guys are saying is there is no point in a double drain if I have already done it to change out to synthetic. Thanks for the tip!!

 

My truck coming up on 100k, fluid in there was in there when i got it. Is there anyway to tell if it's synthetic? I'll be changing it out this summer, I would do the hoot method if its syn. If not best to double drain? I will be going synthetic.

 

Whether Dex VI or Transynd both are synthetic.

I would recommend the Double Drain because it INSURES you don't harm your transmission. With the Hoot method you can possibly run it low on fluid and damage it

The little bit that isn't changed is inconsequential

 

Everyone that has a transmission needs to read the thread in the Transmission Shop section by Tom Johnson, The Transmission Fluids Engineer at Allison from 1990 to 2009.

He knows the factory stuff, but admits he does know what is best for modified transmissions. That tells me that he is not here to stroke his ego, but to help us get the most out of his products that he help develop for many years. I am glad that he took time from his retirement to help educate us.

Thanks Tom!

 

Clear, Complete, Concise and Accurate. VERY well said!

 

I want to switch my factory trans fluid over to Mobil 1 ATF. So I have the new spin on filter and new internal filter. How much Mobil 1 oil will I need?? I will have to do the double drain method also. Just help walk me through the steps also.

 

There aer many threads on here about his very process. Do a search and you will be able to choose what thread to read.

 

Get 4 gallons for the double drain. It’s around 7 quarts to fill after you drain it so you will have about half a gallon left when you are done. I use the rest to drain and fill the transfer case

 

Ok I just changed my transfer case at beginning of year but I used the AC Delco dexron6 oil for that but I don’t mind having oil left over I am thinking I will just buy a 20L pail which is about 5.2gallons it is just cheaper around here if you buy bulk a pail then the jugs.

 

Just remember when you check the level of the fluid your truck need to be turned on. I would error on the high side of “cold” when you check the level. Once you get the tranny temp up to 160 check again and make sure the fluid level is correct. There should be 2 different areas on the dip stick to check the level. One will be cold and the other is hot. The best reading is when it is hot.

 

Better a bit too low than too high in the end. This transmission DOES NOT like to be too full, and shows its displeasure by running hot.

 

Yes you bet the problem is getting the truck up to 160 best I can do is 130 this time of year with that trans cooler. When it is weather hot hot in the summer I can get it up to 155-160 but that is it

 

I’ve found 1/2 way (middle) on the hash mark hot side works best.
On the low mark and top of the high ain’t so good, right in the middle at 160*-180* :thumb.
I know it’s a little harder in colder weather probably 1/4 up from the low mark would be pretty good.

 

I do pretty much the same.

The easy way to drain a little is to unscrew and drain the spin on filter. Screw it back on and check again til you get it where you want it.

 

Hey guys so I just ended up pulling drain plug and changing he external spin on filter for out about 6.5L. I didn’t want to give them a reason to void my warranty so I just refilled with dexron 6 I have put like 7L In so far but the warmest I can get it is to 90* that is driving home on the hwy for about hour and 45mins it is like -18 here when I check it there it is at the cold mark on the dip stick. But today when I stared the truck to warm it up it ran for 25-30mins and when I got in start driving it was at 149* just from idling then when i for driving went down to that 90*. I am worried not sure if I have to much or not enough fluid?? Thoughts anyone

 

You should have checked the level when you had 149*, our outside temps don’t get that low, so it’s hard to give advice when I don’t know.
My guess if your about midway in the cold hash marks you might be ok at 90*.
The next time you see 140’s pull over, put it in drive and leave the engine running check the level.

 

I am going to try leaving it running out side when I get home and see if the temp comes back to that 150-160 and then I will check it there.

 

Living in cold county you don’t by any chance have a grill cover, like the big rigs have.
If not get a piece of cardboard to put up against the grill, just pay close attention to the ECT and trans temps.
This will help bring the temps up to check your fluid level, you might even research this and get one for your truck for the cold winters.
I found a picture with a Chevy with one on just for U.

 

I don’t think you will get much past 130 never if your outside temps are that low. It’s going to be tough to get a real good reading. My advise and some guys will maybe disagree is keep it filled to the cold level temps and when you thaw out in the spring or summer check it again

 

Yes I have the factory grille cover that came with the truck but it does have anything for the lower trans cooler part which I wish GM would have so ya I will maybe get something there this year

 

Yes I have the factory grille cover that came with the truck but it does have anything for the lower trans cooler part

Are you using the grill cover ? If so that’s probably why your ECT went up to 149*
You don’t want to block the whole opening, but you could use anything to cover over part of the lower opening just to get the temp up to verify the level.

The older trucks are able to pull air thru the bottom, newer ones don’t which means you need that lower opening for the trans cooler.
Good luck

 

You might do a little researching, it might be a good idea to use your grill cover more often.
The trans will perform much better shift better when it’s closer to operating temps warmer than the 90* your having.
That’s what they are for when your in the climates you live in.

I even ordered one when I ordered my truck, why when I live in Phx. Az 'dunno; but I did and it’s never been out of its package.

 

Ok update so started truck tonight let run for 20mins trans temp was at 152* and it was just above the cold mark on the dip stick

 

So its still in the cold hash marks, suggested as earlier between the low hot hash and midway at 180*.
152* should be close enough I'd go with the hot low hash mark no more than maybe 1/8" up from the bottom of the hot low line.

 

Just for reference, cold is around 60-80 degrees. Hot is typically between 160-180 degrees. If it is running at really cold temps, even negatives, then the oil volume will shrink accordingly. What you want is in the hash marks at 160-180 degrees. Once that is set then just leave it alone. If you need to, as a stop gap measure, you can figure that -10 degrees is around 80 degrees colder than cold. That means that the fluid lever would be about 80% further below the cold range than the gap between cold and hot. This assumes several things that aren't necessarily true but is a better shot in the dark than some others.

If you are constantly seeing trans temps well below normal you need to take steps to get it to heat up. Any enclosed container, like a transmission, will get some condensation eventually. That needs to be cooked out. If the trans never warms up it will die of corrosion.

I'd suggest a transmission thermostat be installed in the lines to the cooler. The thermostat needs to bypass the oil, not block it. This is an unusual thing to add but you live where the temps are very cold for long periods so it is justified. I see from your signature that you have already done serious mods to your truck. This would be just another in the list.

Until you can do the thermostat, I would suggest that you try blocking the trans cooler with cardboard. Block it all off to start with and see what happens. If the temps get high then tear off some of the cardboard. Do this until it no longer overheats but still gets hot. Your transmission needs to be at the proper temperature. Everything about it is temperature dependent.

 

Thanks for the awesome info!!! I don’t have any mods you must of been looking at someone else’s sig. I am just curious as to other people that live in cold places they must have the same issues I have with keeping the trans warm but yes I am going to do the cardboard trick for the trans cooler and see what happens. I was kind of thinking it would almost be nice if there was a valve a guy could just bypass the trans cooler for say the cold weather times ams then just open back up for summers or warmer weather.

 

To keep this in a much shorter explanation, @ 152* degrees set the level on the lower hot hash mark line up to 1/8” above the low line
Your in below freezing temps, what you have for temps is normal.
Just consider using your grill only cover more often, that’s what it is for in very cold weather.