Shifting Shudders

M

medman1234

Registered
I have a 97 mark 8 and it is starting to shudder between 2-3,3-4,4-OD.
it only has 80000 miles.
It only does this at low RPM's.It does not do it if I am accellerating fast or shift manually at 3000 RPM or so.
I have read the 1-2 Accumulator Piston and Mercon V replacement Paper in the tech section but it reads like it only applies to 1-2 shifts.
Does the 1-2 accumulator fix the other shifts also?I know there are other accumulators on the tranny.
Anybody have this problem and what should I do?
Thanks
MM
 
Replied in your other thread.......

"Sounds like a torque converter shudder to me, you can replace it with a mach 1 or marauder unit for not too much money."
 
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so did i....

"or you can fix it for under 7 bucks. go to napa and buy a tube of doctor tranny instant shudder fix. it comes in a red squeeze tube and you dump it straight into the dip stick tube, anyone who thinks im joking, if you have a shudder, before you spend big bucks, spend 7 bucks, you have nothing to lose and you will be blown away when you try it, i have it in my 93 which shuddered so bad it looked like the windows were going to fall out while it shifted, i put it in, within 1 mile it was gone, 100 % and hasnt shuddered once yet, its also in 2 of my buddies mark VIII's with the exact same results. its a synthetic blend of friction modifiers and other good stuff, im serious, try it, if it doesnt fix it, i'll give you a transmission."
 
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Or, spend more and change your tranny fluid from your Mercon to Mercon V. That fixed my shudder about 4 years ago. And as I didn't know when the fluid had been changed last, it had to be replaced anyway.
 
Not just the fluid but also the filter. Good time to put a plug in the pan for future changes if you plan on keeping the car. Keeps the mess down
 
Putting that band-aid stuff in your Trans isn't a fix. That stuff basically makes the friction material slick so that the abrasive clutch material is no longer grabbing.

There are two problems that got addressed with the expired TSB. Both resulted from poor lubrication qualities of the Mercon oil. This oil didn't have the correct properties to go the distance in these then newer transmissions. Because of this once the oil lost most of its lubrication properties anything that had tight clearances could have a tendency to hang up. This would show up more often than not with the accumulator pistons since they used a small o-ring to seal against the bore. When you lost lubrication properties the pistons would hang up or jerk in the bores as they traveled. This is also the killer of your accumulator springs. Any tilt of the piston because of the hanging up and the aluminum piston to aluminum wall would gall since there wasn't any real lubrication barrier between them. Extreme cases you end up with a piston jammed up in the bore. Part of the fix was the upgraded pistons with molded seals.

Now go to the frictions in the clutch packs and the TC. With proper lubrication these will engage with relatively smoothness until the fluid is expelled from between them which then the should fully lock. Once the lubrications properties are gone these will grab vice slide as soon as they make any contact. This is where the shudder comes from. If left to continue you de-friction the frictions. Take 2 brand new frictions that have not been exposed to any Tran’s fluid. Place them on top of each other and try and rotate them against each other. They don't slide and just grab. This is what is happening when you have shudder in the TC. Now soak those same frictions in Mercon V for an hour and try the same thing. They slide along each other just fine. What they did here is for this fix was to replace your TC since they knew the friction in it was more than likely fubar. Chances are the frictions in your Trans are still good unless the vehicle was mistreated during this. This was the cheapest way Ford could address this without going and replacing each and every transmission.

So now back to the band-aid tube of lube. When you put that stuff in your Trans all you have basically done is added some super slick additive that makes everything in the Trans and TC very slippery. You didn't fix a thing. You still have the old oil that has lost its properties. And a TC that has more than likely lost most of its friction material.

Your best bet is to have the Trans and TC completely flushed and then replace the filter. If it continues and you know it hasn't had the TSB completed then you need to do it yourself.
 
i guess i should have been more to the point about the band aid fix, now that i have done this to my 93 and it took the shudder away, i am going to flush it completely and refill it with brand new merc 5 and a new filter, what i was trying to find out, was if the tranny was shot, but after seeing this stuff take the shudder out, i will invest in new fluid and filter rather than a new trans. i didnt mean to sound like you put it in, and leave it and your good to go, i knew when i put it in that if it was to work, that it was only temporary. my 93 just turned 100k and i have no history on the car so i will assume in my head for all i know the trans fluid could be original, so now its time for a freshen up!!!
 
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