Transmission Fluid Change (flush?)

[greg1262002]

So here I am coming up on 4 plus a bit years on my Transynd. What between Covid, getting older and other things haven't been driving the coach much and that doesn't look to change in the near future (especially the getting older thing). Anyway, the Transynd should be changed based on age if certainly not miles - yes? 

But the shop I scheduled with also suggested a flush. I seem to recall having read in automotive applications transmission flushes  aren't necessarily a good thing. Does the same apply to diesel pushers?

Can't remember if my signature block is inserted or not so may be a duplicate ..  thanks 

Greg t 

2000 Dynasty 

 

 

 

 

[Bill46]

As a automotive mechanic I don't like a flush. Because it breaks away particules that can get stuck in the valves.

Bill46

[Chuck B 2004 Windsor]

Allison considers motor usage of it's transmission light duty.  replace the filters.  They are found on the bottom of the tranny in two ports.

[vito.a]

I also don't like the transmission flush.  I would recommend changing the filters and fluid using Allison Transynd or equivalent.  

[Old Dog]

If you're not logging very many hours/miles then I  would run it longer. If you're concerned have a lab take a look at a sample. Would be an expensive job just because the fluid is 4 years old. These synthetic fliuds are very good. Just my 2 cents.

[Chuck B 2004 Windsor]

Motor home usage as light duty use.

[Paul J A]

Contact a Allison certified rebuild shop and have them perform the recommended maintenace. Opinions and speculation prove that type of results.

[Bill C]

39 minutes ago, Old Dog said:

If you're not logging very many hours/miles then I  would run it longer. If you're concerned have a lab take a look at a sample. Would be an expensive job just because the fluid is 4 years old. These synthetic fliuds are very good. Just my 2 cents.

How do you get the trans fluid out for the test and where do you take it to for testing?

[Gary Cole]

I've been using the transmission pump to fully flush my transmissions for the last 10 years or so. The process is no different than normal pump operation so I would consider the danger of particles breaking lose myth. All the transmission knows is that the sump is full and is happy 😏. One does want to insure that the sump remain full with new fluid so as not to introduce air into the pump circuit. Though accidentally running the system dry would cause no damage. One leaves approximately 10 quarts of old oil in a 3000 Allison if the transmission is not flushed.

I suspect the reason some particles might break away after an oil change might be due to the detergent action of the new fluid and have nothing to due with a flush.

Edited December 7, 2021 by Gary Cole

[Old Dog]

Use a sampling pump, has a small hose that goes down the dip stick tube. As far as Labs, there are hundreds. Large oil distributors often sell kits that are prepaid and include shipping envelopes. Auto parts store may even offer the service? Cost can run from $15-$30.00. I got a case of 50 kits through an Amsoil Distributor for like $300.00. I test everything and it extends your change intervals a lot. Also can catch problems before catastrophic failure.

[Steve P]

My Allison manual says the life of Transyd is 150,000 miles for light duty and 75,000 for heavy duty between changes.  Why all this concern about flushes and changes and filters?  Or did I speed read and miss something? 

[jegall]

I changed fluid and filters last March I put in 28 Qts it a very simple job took about an hour . I have put 11000 miles sense and no trouble runs cool and smooth shift.

[1nolaguy]

Greg T - I may have missed what type of transmission you have so this information may not apply. I have an Allison 6 speed on my Safari DP. About 3 years ago I had a lengthy discussion with a gentleman that was envolved with the development for the fluid used in Allison Transmissions over the last 20 years. He advised their fluid is designed to run for 100,000 miles before requiring change unless there is an issue with the transmission that contaminated the fluid. His recommendation was that the fluid should be tested annually but only changed if required.  There are numerous qualified testing facilities such as https://www.intertek.com/automotive/atf/ that can advise how to properly collect a sample and sell the equipment and testing. Testing can run from $25 to $50 and the equipment is about $50. They also provided testing of engine oil and radiator fluid. The test reports are not basic (as in change or still good) but detailed to TDS, particulates, and metals that indicate ware or erosion. This information will not only tell you if the oil needs to be changed but also what possible underlying issues that might exist, changing possible future repair to just preventative maintenance. If you have an Allison transmission, or even if you do not, you may want to pursue this before proceeding with a change which is likely going to be more costly. JMO

[BigNick]

I read somewhere else about a joint called Blackstone Labs.. I don't know about it the lab from experience but I do know the Transynd is $500+ (probably more) so a little $50 test is worth it.

Edited December 8, 2021 by BigNick

[cbr046]

There's no acids, soot or other contaminants from a combustion process.  I'm not an expert but trans oil doesn't age out or break down like engine oil does.

If you have your oil tested (engine, trans, generator, whatever) the lab will need to know exactly what kind of oil you're testing (brand name and model, like Mobil1 Extended Performance 10w-30).  If don't know or you've topped of with a different brand / kind of oil all bets are off.  You'll still get a generic report but not as valuable as knowing what was in the oil to start with. 

That said, I read a poster in an auto shop that said AT's fail after an average 74,000 miles, which was right at the Fleetwood's mileage at the time.  That scared me enough to have the Ford 4R100 transmission flushed.  The shop owner, a trusted friend, told me the synthetic oil would last forever.  Still going strong when I sold it 80,000 miles later. 

I believe our 4-Runner still has the original trans oil.  340,000 miles and still our go-to vehicle for running errands, traveling, etc. 

- bob

[1nolaguy]

There are many factors. My Mazda 2005 Tribute with auto tran. was rebuilt at 100K and the oil changed. I have it tested regularly. Now at 240K and still going strong.

[greg1262002]

Thanks, getting a test is a good idea. Made me remember I have a sampling pump I got when I was dealing with a coolant issue. 

Greg t.  2000 Dynasty

 

 

 

 

 

 

In the next adventure in coach maintenance I go to get a kit and find my coolant sampling pump won't do. Makes sense if I'd thought about it..  

Greg t 2000 Dynasty