1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Tranny flush

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Old 07-23-2004, 04:30 PM
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you gearheads need to learn your place!

j/k

anyhew, you don't need to worry about the pan gasket - it'* a flat gasket all the way around and has plenty of sealing surface. as long as you start out with two dry sides, it'll seal up. heck, you could probably even start out semi wet and seal up... it'* intentionally made to seal up under not so perfect circumstances.

while you're in there, clean off the magnet in your pan, but make sure you put it right back where you got it from... its usually marked inside of the pan, but its there to catch metal shavings off of your gears... which despite what would seem good or normal, is quite good and quite normal in any trans.

in any event, i know of lots of these trannies that have never been serviced after 100, 150k miles etc and work fine.

but if you want to do it, by all means.

most dealers will do a simple flush w/o the filter... they have the convenience of hooking a machine up to the send and return lines on the trans cooler and just turning the thing on... which is a simple hard to screw up thing.

but then again, if you have a clean place to do it, it'* not really a hard job to do by yourself.

but then again (again), if you don't feel comfortable, don't do it. no reason to do something if you don't feel good doing it.

good luck!

matt
Old 07-23-2004, 04:44 PM
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Nice recovery, folks.

For starters, our gearheads are gearheads for a reason. They know they're in a tighter spot than anyone else if they dish out bad advice. Accountability is at a higher level.

Foghorn is one of the few here that I would trust completely on my own car. And I agree with his suggestion as well.

The 4T60 and the 4T65 really act like different animals as far as heat and fluid life are concerned. I don't have a clue why. Alot of the success or failure of a flush is dependent on the root problem in the trans, which is VERY hard to diagnose.

Changing the filter and reinstalling the pan without leaks is very easy, assuming you follow the correct procedure in any of the 'big 4' (Factory, Chilton'*, Clymer, Haynes) manuals.

My gut tells me that unless you've diagnosed the problem with a scantool like I did, tread carefully. The SAFE thing to do is exactly what Foghorn suggested. Pan and filter, and that process will only get 1/3 of the existing fluid. No drastic changes that way, and you'll know that you're running proper line pressure with the fresh filter (assuming the pump is healthy). Taking a look at the pan and magnet during this process is one of the best reasons to do it this way.

Assuming you find no major problems, and have increased performance, at that time (maybe a month later) I'd consider a full flush to get the rest of the old fluid. Baby steps. The flush will also determine your line pressure and give you an indication on the health of the pump.

In YOUR case:

1. Scan and diagnose if possible.
2. Pan/gasket/filter fluid (1/3 of fluid, gasket should be re-usable).
3. Wait 30 days, if all is well, flush. This is partially dependent on what you find in the pan and the color of the fluid after 30 days.

And as always, this is the best I can do from a distance. Troubleshooting these things from afar and giving advice can be tough AND touchy.
Old 07-23-2004, 05:47 PM
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I'll give Bill'* method a shot. I was thinking more about it on the way home. Drop the pan, get whatever fluid out that I can, change the filter, and reassemble. Then drive for 1,000 miles and then do a flush.

The reason I mentioned the sealing problem with the gasket is because I've had a couple times when the seal didn't take. That is all.

Thanks for the tips...
Old 07-23-2004, 06:03 PM
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Foghorn beat me to it

Proper torque sequence and torque values. No worries. Torque them to 1/2 value in the right sequence, then take them the rest of the way. Same sequence as the first time. Criss-cross.
Old 07-23-2004, 06:14 PM
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Originally Posted by willwren
Foghorn beat me to it

Proper torque sequence and torque values. No worries. Torque them to 1/2 value in the right sequence, then take them the rest of the way. Same sequence as the first time. Criss-cross.
Yup. Precisely. That'* how I like to do it too. Hopefully I'll have good results.
Old 07-23-2004, 06:29 PM
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Wow, a lot has happened here since i left. Anyway might just leave the tranny alone for now, at least until I get some money to replace the fluid. The tranny in my car has no problems that I know of and shifts fine so i think it can make it another few hundred miles until then.
Old 07-23-2004, 07:39 PM
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Default tranny

I do the pan and filter thing around 50k with no problems.
A good way to check the condition of the tranny is pull the dipstick look at the color
of the fluid and then smell it.
I'm not too big on flushing as there are a lot of o ring seals that could be washed too clean and cause pressur problems.
Old 07-24-2004, 06:41 PM
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The oil change places like to sell tran flushes to make money but when your trans fails later they will take no responsibility. I have heard this story many times. When you let them hook your trans up to a flush machine you will get an STD (someone elses transmission debris).
Old 07-24-2004, 08:09 PM
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That depends on the type of machine they use. I've had mine flushed at the same shop twice in two years, and the way the machine is setup, it'* not a danger.

My old fluid enters one side of the piston and pushes it up (using the transmission for pressure), forcing the new fluid in the top of the piston to enter my system.
Old 07-25-2004, 07:05 PM
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Originally Posted by jr's3800
If your car has never had a tranny service, or the filter pan gasket and fluid replaced, and you still have the original pan gasket do not discard the original..... Keep it and reuse it as its the best one you can get.... The cork and or rubber gaskets will leak sooner or later... Hang on to that factory pan gasket...
Yes. That'* what I'm doing from now on too. I think that'* why I ran into many issues with them not sealing properly (as I mentioned earlier in this thread).


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