Trans fluid flush and filter change

[jnicks01]

Is this a waste of money? I have 161,500 on my 99 4x4 LT. I was considering taking it to Aamco and having them completely flush the fluid, change filter and gasket and replace with synthetic. I have a very slight slip when shifting and was hoping this could help a bit. Plus it's never been done and would assume the $100 or so would be worth the "preventative" maintenance. Thoughts/Experiences to watch for?

 

[jrstallion51]

If the transmission has never been flushed and this is the original trans, I wouldn't recommend flushing it. In my experience as a mechanic, almost all higher mileage cars had issues immediately after the service be it leaks, slips, or what have you. I would however recommend doing the service yourself, just a fluid and filter change and if you wanted to run a mild flush (at any parts store) through the trans before hand, that would be excellent. I would also recommend adding a quart of Lucas trans treatment or something comparable to help extend the lifespan just a little further.

Keep in mind, if she's slipping all of this will just be a band-aid for the inevitable, a replacement.

 

[blk87brd]

At 161 K, I think you are way beyond any benefit a flush would provide. I'm lead to believe these transmissions tend to go in the 100 to 150 K range, so your slight slip is likely an early warning that you are on the verge of a trans rebuild. I'm in Canada which is tougher climate on equipment like auto trans, but my first trans (in a 99 Tahoe) went at 156,000 Kilometres. A friend who had a twin Tahoe made it to around 200,000 Kilometres.
Both of us had used GM regular service of which part is for the trans. After I had Ammoco rebuild my trans to include HD parts, I had it flushed and serviced every 50,000 Kilometres and I put close to 300,000 Kilometres on it. The friend continued to go to GM (who did his trans rebuild) and his went out again 120,000 Kilometres later.
I suggest getting a core from the autowreckers, getting it built by a reputable shop and then changing before you are walking.
Regards
Tom G.

 

[Mike97]

I have read arguments for and against transmission flushes, but the majority seem to say not to do it if you have high miles. And if you decide to go ahead and do it anyway, do not use synthetic fluid. I have decided against flushing mine, it has 130,000 miles on it. Instead, I plan to just drop the pan and replace the filter.

 

[jnicks01]

Thanks guys! After further research, I have decided against the flush. Everyone says its a BAD idea. I will however replace the filter and whatever fluid ends up on me and the garage floor. I usually buy from Rockauto for parts, but they have about 25 different filters. MY Tahoe is a 99 4x4 with a 4L60-E transmission. But I'm not sure if I have a deep pan?! Are the 4 wheels deep and 2 wheels shallower?

This is the part # that I have deemed correct on rockauto is as follows...

ACDELCO Part # TF337 {#25325578}
FILTER KIT,A/TRNS FLUID 16 HOLES, DEEP PAN; 4 WHEEL DRIVE; 4L60-E TRANS, 4 SPEED

Does anyone know if this is right. My gut tells me it is, but I'd hate to have to jump in the girlfriends car for a trip to Napa 1/2 way through my repair.

 

[Hardwarz]

I'm going to be doing that this summer. When I drop my pan, I'm replacing it with a pan that has a drain plug. I'm also a fan of putting a magnet on the pan. On my old Dodge Intrepid, there was one there from the factory.

Hardwarz

 

[KJLegend]

What are some of the links you read up on flushes/dropping the pan etc..???

 

[Mike97]

Thanks guys! After further research, I have decided against the flush. Everyone says its a BAD idea. I will however replace the filter and whatever fluid ends up on me and the garage floor. I usually buy from Rockauto for parts, but they have about 25 different filters. MY Tahoe is a 99 4x4 with a 4L60-E transmission. But I'm not sure if I have a deep pan?! Are the 4 wheels deep and 2 wheels shallower?

This is the part # that I have deemed correct on rockauto is as follows...

ACDELCO Part # TF337 {#25325578}
FILTER KIT,A/TRNS FLUID 16 HOLES, DEEP PAN; 4 WHEEL DRIVE; 4L60-E TRANS, 4 SPEED

Does anyone know if this is right. My gut tells me it is, but I'd hate to have to jump in the girlfriends car for a trip to Napa 1/2 way through my repair.

Your link is broken. It sounds right from the description though.

 

[jnicks01]

KJLegend, I found one the other day through a random search.

http://autorepair.about.com/od/otherodddiyjobs/ht/trans_filter.htm

See what you think

 

[YukonMud]

Seems like you have already done what you needed to, I just wanted to let you know that everyone in my area says to stay as far away from Aamco as possible.

 

[scooter8145]

I have spent some time in a transmission shop and believe that a very good product is the BG flush and power purge. One of the best warranted products on the market. I do agree with the mechanic above; if it is slipping...it most likely will get worse without some attention

 

[KJLegend]

Thank you for the link jnicks, I did check it out but I called a friend of mine who manages a local 'jiffy lube' and he said the flush they do is not harmfull at all what so ever and to bring it by for a $50 cash deal. I did that just for piece of mind, and to save a t-shirt from getting all messed up again...Because everytime I go under a car I end up messing something up and getting covered in liquids lol... Anyways he assured me that it would not hurt my car at all and I trust him not only because he works at jiffy lube but because he custom builds cars on the side so he knows a bit... I will probably have him do the Yukon pretty soon too since she's just over 100k miles now so she could use some new fluids. As for the Legend, it seems to shift a little smoother than before but it was pretty bad before so its not a huge difference. I'll probably end up replacing the tranny or selling the car as is.

 

[Mike97]

I'm not trying to start any fights here, so no offense to you or your friend KJLegend, and it's great that you have that much trust in him. But if transmission experts can't agree on whether or not it's a good idea to flush automatic transmissions, how can he know? Custom building cars doesn't automatically give you knowledge about automatic transmissions. In all the reading I've done on the subject, I was unable to conclusively determine if this is a good idea or not. The general consensus is that if you have more than 100k miles on your transmission, and it's never been flushed, it is a bad idea. Mainly because there is likely a lot of sludge and varnish built up inside. The fresh additives from the new fluid attack the deposits, causing them to break off and jam valves, clog passageways, etc.

I have also read that you don't want to ask anyone at a quick lube place whether or not to flush. That's kind of like asking a body shop if you should have a dent fixed. They are trying to make money from a service. Of course they are going to say yes, and some have been known to flat out lie in order to get your business. I'm not saying that your friend is lying to you, and maybe he truly believes what he is telling you. But you should not take one individuals advice about something that even the experts disagree on.

 

[telmd]

+1 mike97

 

[Hardwarz]

+1

If you have:
Fresh transmission
Always flushed your fluid at the required intervals
New vehicle

Then by all mean, flush your transmission.

If you've never done it and have 90k+ miles on it, don't do it.

Likewise, if you buy a used vehicle with 90+miles on it, don't use engine oil cleaner on it. You don't know what the people before you did and if you do use it, you could end up loosen a lot of varnish in sheets. I've had friends that did this and it jammed up the oil pump. $$$$

Hardwarz