I have a 2002 Blazer with 50,250 miles. The owners manual says to change the tranny fluid. Is flushing a better option. The GM dealer wants $187.00 to flush and almost $300.00 to drop the pan and change the fluid. I had a 95 Blazer with 175,000 miles and had it flushed with not one problem. Any suggestions?

 

Low miles!

I would have it flushed only, but that seems VERY expensive.

The transmission is a closed system. The filter can only be clogged by stuff coming off of the various wearable parts in the transmission. Typically if the filter is clogged, the transmission is on its last legs. By keeping the fluid refreshed, you can really extend the life of the transmission overall.

 

Flushing is a somewhat new option that just started coming around in the past ten years. I really think it's just one more way to make a few more dollars off of a maintenance service, and really isn't necessary. In some cases, the additives that are sometimes used during a flush can cause more damage to the transmission by stiring up normal sediments in a high mileage transmission and cause a premature failure. Take your Blazer to a transmission specialist and just have the basic service performed.

 

This is not a high mileage vehicle and typical flushes use straight transmission fluid, no additives. What you have stated doesn't really apply in this case.

 

So if a vehicle has higher miles, say 130k or so, should it be flushed or drained then? I'm a little confused. Some people say its bad because it happened to so-and-so or it pushes stuff where it doesn't belong. My Blazer has 132k as of this morning and I was thinking of having the trans serviced but not sure what to have done. Tried to have my Dodge done when the trans got close to 100k but the place I took it to said I shouldn't because with the high mileage, after flushing the trans, it could go out anytime. Sounded fishy then and still does but I'm not a mechanic...

 

Around 50k miles, I would do a flush.

Between 50k & 100k and knowing the service history, I would not do a flush unless you were to drop the pan and inspect the magnet in the pan for signs of damage done to the frictions & steels. If it is relatively clean, then the transmission is probably quite healthy and a flush wouldn't be so bad.

If over 100k and not knowing the service history, I wouldn't do a flush.

A flush really won't stir stuff up from the pan, but it can pull debris away from seals that may be plugging up a leak.

 

Save yourself some money and just have the regular service done. It will give you a better idea of the health of the transmission by showing you what's in the pan and give access to the filter, both of which the flush does not.

Hard to imagine how a flush can pull debris away from a seal, but not the pan. If you're really set on the flush, make sure to have the regular service done first.

 

I guess I should clarify what type of flush I was mentioning. A fluid exchange flush or ultra-sonic flush of the transmission uses two large reservoirs, one for the old fluid and one with fresh fluid without any additives and connects to the cooler lines. The fluid that comes out of the cooler feed line is captured for disposal while the flush machine pushes clean fluid back into the cooler return line at the same rate as the fluid is being pumped out of the transmission. In the case of an ultra-sonic machine, ultra-sonic pulses are back fed through the cooler feed line to loosen any debris from inside the transmission components. Most ultra-sonic machines do not pulse the return to the pan nor is the feed rate sufficient enough to stir up the debris in the bottom of the pan.

If the transmission is healthy (under 50k miles with good fluid condition) there shouldn't be much anyway.

I do not like the chemical flushes at all; and especially not the a DIY flush jobs that you dump in the dip stick tube and drive for 200 miles or so, then drain. Either can cause problems with seals, etc.

To keep a transmission healthy, keep the fluid in good condition.

You can do a DIY fluid exchange in your driveway with some clear tubing and a bucket marked in intervals of 1-2 qts. Identify the cooler feed line and plumb it to the bucket with the clear tubing. Start the engine, monitor the level in the bucket; shutting down the engine when the level reaches 2qts. Add 2qts to the transmission and repeat in 2qt increments until the fluid comes out noticeably more clear. The dry capacity of the 4L60E is ~12-13qts and you may need up to 18qts to get to clean fluid depending on how spent the old fluid is.

 

So it is good to change the fluid. I thought so. I was told the transmission "gets used to the old fluid" which I thought was a crock but didn't say anything. Maybe they meant that in respect to a flush. I dunno. It just seems the Blazer is going into gear a bit harder than normal so maybe this will help plus I think the owners manual recommended it a while ago

 

just do the driveway flush like Swartlkk wrote above. its the easiest, safest, and most conveint way to do it....