to flush or not to flush??

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  #1  
Old 01-20-03, 10:21 AM
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to flush or not to flush??

Well, the 94 tbird 3.8L is acting up again. I have "torque shudder" shifting from 3rd into overdrive, feels like I am going over train tracks.

Transmission is an overdrive auto r470w model.

I have done my homework on this problem, and it seems that the general consensus to to go ahead and flush out the entire system--pan, torque converter, radiator trans lines and all, hook it up to a machine and have the whole system flushed. Fine.

I have gotten several estimates around $150 or so.

Only thing worries me is advice given from a shop that I am told not to trust anyway---AAMCO. I called him and wound up getting into a fierce debate about torque shudder and trans fluid.

See, from what I have learned, the "shudder" is caused from the fluid overheating and burning, thus breaking down viscosity, and everything essential to do it's proper job. Since the fluid is burnt and spent, the torque converter shudders.

Flush out the system, replace with mercon V. However, AAMCO guy tells me that they would never ever buy a flush system for their shop because it will essentially "flush" out the whole tranny, meaning, ruin it and rendor it useless. He says that they need to find the "root problem" of the shudder. I tell him it is burnt spent fluid but he argues that it is deeper, and not caused by the fluid. WHile the torque converter may be weekened, many say a flush with mercon v has fixed their problem
I think I am right, but need to be corrected if not. I am going to go ahead with the tranny flush because I believe it will be ok, but if not, I need to know now. The tranny was rebuilt 40k ago, but of course has never had the fluid changed yet.
 
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  #2  
Old 01-20-03, 10:30 AM
Joe_F
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Jeremy:

WAAAAY too long on a fluid change . 25k with the filter, every time, on time.

Yes, I agree with you, try a tranny fluid change and flush/filter. If nothing else, you'll just be back to square one. Absolute worst is a tranny rebuild again, which honestly, exceeds the value of the car---yup, I know you put a ton into this thing.

You've got nothing to lose.

I'm with you on your methodology. I simply drain my fluid and filter every 25k and have flawlessly shifting Hydramatics.

Then again, Ford trannies couldn't hold a candle to a Hydramatic anyhow .
 
  #3  
Old 01-20-03, 10:42 AM
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Thanks joe for the great reply--

I know 40k is way too long. unfortunetly I have to admit that I downright suck at maintaining a car. This is why I have to own something bulletproof like my 5.0 mustang. No trans fluid to change with a five speed, no clutch fluid as it is cable driven. Brakes?? who cares mustangs don't have brakes anyway, and a bullet proof 5.0.

However, agreed, this car isn't worth any more $$$ With my tax returns on schedule for feb. I hope to get enough back to pay off a credit card and pick up a 2k + gt mustang.

However, since I don't care much about the tbird, if the tranny nukes, I am playing around with the idea of finding acheap c-4 out of a v8 and throwing that in. Who cares about Over drive right? Gas milage is overated anyhow.
 
  #4  
Old 01-20-03, 10:55 AM
Joe_F
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Jeremy:

It's cheaper to just buy one with a V8 if that's what you like . I happen to think these are nice riding cars, but have poor quality especially the powertrains, but that's just me.

Drive this one until you can afford to replace it with something better or you like.

As for fuel mileage, well----it's not overrated. I have a 4 cylinder Cavalier that was given to me that I intermix with my 307 Oldsmobile in it. Neither car is a powerhouse, but both get me from A to B in style and comfort and reliably. The Oldsmobile more so than the Chevy of course

It's great to pass gas pumps with the Chevy. LOL. No car is worth any kind of debt at all.

I have my classics and I have my every day cars. I just drive my everyday cars and keep them clean, polished and well maintained. In turn, they reward me with a lot of service. I never have abused a car.

In the rare instance I do sell one of my cars, I simply tell the guy calling on the phone, "The price is the price. Don't like it? There's 10 guys behind ya ".

I believe in keeping things going with good upkeep and maintenance for a VERY long time. LOL.
 

Last edited by twelvepole; 01-24-03 at 08:58 PM.
  #5  
Old 01-20-03, 01:09 PM
1fireman
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I had the exact same problem in my '97 Cougar with the 4.6. Which is nearly the same as your 94 tbird, just a different engine. Great cars when properly maintained, but they fall apart if you don't. The dealer did a flush on my tranny and I haven't had a problem since. I had bought my car from the dealer with 48K on it and put 10K more when I ran into the problem. I came to find out they never flushed the tranny when they took it in on trade. I won't let that one slip again.

Anyway, a system flush and filter should definatly fix the problem. It was 125 at the dealer two years ago.
 
  #6  
Old 01-21-03, 01:12 PM
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Years back my 3.8 engine on my buick was doing excatly that; the trans guy told me it needed to be rebuilt and now I see why it did not take care of the problem. the trans finally failed and ended up in the junk yard after the tran guy supposely tried to fix it twice.
I feel I lost a good car. only if I had know.
anyway that subject is history- will live and learn.
how often should an auto trans be flushed?
 
  #7  
Old 01-21-03, 03:32 PM
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Save $ on the flush...Fords have a converter drain. So by draining the converter and dropping the pan you will get 95% of the fluid out. Add a bottle of "Lube Guard" used by trans shops to prevent the shudder(it's not necessary but will help).

This is a common Ford problem and is corrected by changing the fluid

Larry
 
  #8  
Old 01-21-03, 03:37 PM
Joe_F
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Handy:

Fluid and filter changes every 25k.

Also depends on what vehicle you are talking about as to if you "lost a good tranny or not"
 
  #9  
Old 01-23-03, 11:52 AM
redneck
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First off all if the tranny shop will not due a flush--then take it elsewhere. They are right about the root cause--root cause is the trannys are junk--and the fluid should not be toast at 40k unless you are pulling a trailer or drag racing. 25K is way too conservative (maybe not for a ford), but I change mine at 50k, and oil at 5k--course I run mobil 1 in everything I own. I have never had any vehicle(and I have had many), have a fluid related break down!! My '98 GMC just got changed at 50k, the fluid was perfect--looked like it just came out of the bottle! And I USE this truck--pulling my 19ft fiberglass boat, 4 place snowmobile trailer(buddys), 3500lb cars on 2000lb trailers, etc.
 
  #10  
Old 01-23-03, 12:34 PM
Joe_F
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You've gotten VERY lucky over the years. That is considered severe service and wipes the fluid out pretty quick. Why gamble?

My .02
 
  #11  
Old 01-23-03, 12:57 PM
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I thought I would post to this thread as it is an interesting subject. In general don't you find it interesting that most people will break a leg to change their engine oil at 3000 miles but yet never even consider the tranny fluid and filter until the tranny goes out? Considering the transmission is so much more complex and susceptable to fluid failures the logic seems sometimes backwards. Also if the tranny goes out you're looking at $1500+ for a rebuild as you can pick up a long block for an engine for $500. I guess the transmission is still very mysterious to most and gets neglected. I'm for using the severe duty charts in my Factory Service Manual for fluid maintainance as oil and filters are cheap insurance. Thats my 2 cents. Have a nice day!
 
  #12  
Old 01-23-03, 05:57 PM
Joe_F
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Well put Stevo.
 
  #13  
Old 01-23-03, 08:24 PM
kevin18
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My dad keeps his truck in good condition by changing transmission fluid and oil plus all the other even changed his timing belt at 100k and it still is a junker. By the way it is a 89 chevy silverado.
 

Last edited by twelvepole; 01-24-03 at 09:00 PM.
  #14  
Old 01-24-03, 07:44 AM
Joe_F
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Right.

Basic maintenance is what I've been prescribing on this and every post.
 

Last edited by twelvepole; 01-24-03 at 09:02 PM.
  #15  
Old 01-24-03, 09:14 AM
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Bought my 94 TBird new, it had the shudder after about 20,000. Change the fluid about every 25,000 and it takes care of the problem. I have over 100,000 on the car with no major problems. Drain it change the filter, drain the converter and put good fluid in it.
 
  #16  
Old 01-24-03, 02:15 PM
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Thanks for the tip on doing it myself joe. I was set on taking it into a shop, (they all wanted around $150) I just can't see spending that on this car. Although the thunderbirds can be an absolutely wonderful riding car, it seems as though a automatic self destruct switch wired into the ignition switch...so that every time you start the car, another part blows up.

Oh well. Since you said that draining the torque converter and pan gets 95%, I have my project this weekend. How much fluid does the radiator store??? You don't think that is anything to worry about?? or should I undo the lines at the radiator and let it drain???

BTW, I was told to change the tranny fluid at yearly intervals, so I believe joes 25k is being liberal.

Joe, you should be proud of me...I was helping my friend get a new (almost) car this weekend, but he didn't have much to spend. (10grand or less) We went to the ford dealership, because they had special financing. There were three cars that fit his budget...a Chevy cavilear 4 door, a Kia spectra 4 door, and a 2000 Ford Escort 4 door. Well, me being the Ford guy, I had to do what I never thought I'd do. I steered him WAYYYYY clear of the escort. We looked at the cavilear, and the Kia.

To tell you the truth, and I hate to admit this, but the Kia felt 100% better built than the chevy. As much as I wanted him to get the chevy, I could not deny the quality of the kia. We went home with the kia. BTW, these were used cars, otherwise I wouldn't have allowed him to buy foreign.
 
  #17  
Old 01-24-03, 03:01 PM
redneck
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If the trannies are prone to problems--by all means change the fluid all the time. I am considered by everyone who knows me to be very anal about maintenance. Between my father and I we have never had tranny problems at the longer drain intervals. One of the best things you can do to any auto tranny is install a cooler. My truck is a heavy duty 1/2 ton and has a factory oil and tranny cooler that along with mobil 1 fluids is why I drain at longer intervals. Every car and the way it is driven is different.
 
  #18  
Old 01-24-03, 04:01 PM
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Flush machines are good for cars that don't have converter drains.

They work on the theory that the new fluid pushes out the old. Some mixing of the new and old takes place. You can see this if you use a flush machine on fluid thats dirty. After flushing with the recommended amout of fluid for that trans the fluid will still be dirty. For the fluid to come out clean you have to "over flush" with almost double the capacity depending how dirty it is.

As far as the cooler you could drain it, for your problem it won't matter. Just dropping the pan and draining the converter will fix your problem. Make sure you use a top quality fluid.

Larry
 
  #19  
Old 01-25-03, 05:32 AM
Joe_F
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Jeremy:

You should be fine with the draining and refilling as noted here by everyone. It should help out with this problem.

Torque converter shudder is common on these models.
 
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