Tranny Fluid Change?

[Taholio]

Hello All,

Been a while since I have been in. I hate to use you guys only when I have a problem but the best place for unbiased advice are other owners and modders! I have a simple question, one that is split about 50/50 when I google it. My hoe has 150,000 even on it, original everything and its been a rock solid truck so far, only changing the water pump and alternator in it's life. I have no idea if the tranny fluid has ever been changed. I tow ocassionally maybe once or twice a year helping friends move but never really heavy. Should I bother or will new fluid up pressures and cause my back up transmission to come out of hiding? Thanks for any advice guys/gals.

Dan

 

[rockenthebowtie]

Yes if you've never had It servied getter done only at this point have the filter and pan gasket replaced also I do recommend that you have a complete transmission fluid exchange all 15 quarts not just whats in the transmission pan

 

[Gzes]

This is a long debate. Lot of people say yes and lot day no. I've seen transes slip after a change and flush. I personally don't do it unless it acts up and really just do the filter. Have cars with quarter million miles and are fine no slips or popouts

 

[rockenthebowtie]

If you maintain regular routine services up to date those issues for the most part do not surface also if theres no symptoms for the most part dont surface either... but if in your case of never doing it till theres a problem then most of the time they will suface but why change the engine oil eithet if you get 1/4 mill out of them... lol

 

[clandr1]

I have 117k on Yukon, and I spoke to the service manager at the local Chevy dealer here last week about the transmission. He said he does not advocate a flush, and suggested I only do a drain/refill (replacing the filter, of course). He said that, over time, particles deposit themselves in crevases which serve as a sort of seal to certian parts. If you flush, you run the risk of removing those deposits which could cause a catastrophic transmission failure which means you'd need a rebuild.

 

[rockenthebowtie]

Thats funny I am a GM certified tech for over 25 years now and my service manager doesn't no jack about a vehicles operation let alone transmissions... again if vehicle's are kept up that should be nothing to worry about as far as doing whether it be a trans pan and filter change or a complete fluid exchange with filter and gasket if its going to happen it will do it with either service.. again 25 years and I've probably only see that happening 1 in 25 and thats because it was to the point of failing due to extream towing or they pretty much just drove it into the ground

 

[ezdaar]

If you do the drain and fill method at the radiator, its safe. Fluid passes through the trans like normal. your just replacing 2-4 quarts at a time till its all new.
Reverse flushing is BAD. This is the one that loosens debris and trashes a trans.

Flush procedure and parts list can be found here.

Some duct tape, Tape the hose inside bucket at top to keep it from flying around.
What that guy doesn't really say very well is while your watching the tubing.
As soon as you see bubbles KILL the engine!
Don't mess around, pay attention.
This takes aprox 20 mins and will cycle all the fluid out for fresh and allows for a spill free filter change.
Smell fluid on the dipstick before. then smell it when its in the bucket.
What doesn't smell burnt on the stick, is a holy shit that's burnt in the bucket.

If you really want to extend life of your trans, Do this.
Tru-Cool Max Trans Cooler 4739 & 47391 Install Kit - Brackets & Fittings & Hardware
This kit goes on every single street and track truck, suv, that me and my buddies build.
No exceptions. The customer says no, we say get to walking.

 

[mattluttrell]

Hi Taholio,
I could not believe how easy the complete fluid exchange method was at the radiator.

I had 16quarts of fluid, a $10 pale pump, a small clear hose, a bucket, and a brass adapter. It took about 15 minutes to turn my black ATF to red.

I did this and the rear diff fluid as soon as I bought it. I've put another 10K on it (155k) since then. It is great peace of mind.

I recommend it. I also did a minor oil flush, plug and cable change.
- Matt

 

[JBTJ]

YES, you should replace the internal filter and do a fluid exchange. I bought mine with 118k and the fluid was black, you could tell the PO never touched it before. I added on an external filter so I no longer need to crawl underneath to drop the pan and change the internal filter. This method also makes exchanging the fluid a simple 10 minute job. Here is my external filter. http://www.tahoeyukonforum.com/forum/showthread.php?t=61672

 

[mattluttrell]

Forgot to add, the service manual says we all should have at 100K or earlier.