Tranny Problem

B

budpytko

Registered
When the engine is first started/driven, the trans. will not shift from 2-3 correctly. It goes into a no-drive condition (almost like shifting into neutral), then "catches" after a few seconds.

If I lock out overdrive, it seems to lessen the problem, maybe it will still do it, but usually will shift correctly. Once car is completely up to normal temp, it doesn't do it any more that day.

1997 Gen II LSC with 121,000 miles. Changed to Mercon V many moons ago ( have had 2 flushes since changeover from reg. Mercon)

My question: Will installation of shift kit solve this problem. If so, what kit is recommended? Can I do it with car in driveway? No garage available.
 
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Sounds like your clutch pack is toast. There are some tricks that will prolong functionality (friction modifiers, shift kit may make things worse), but you'll want to get the clutches replaced eventually. I don't think it is an overtly expensive job.
 
Losing 3rd and 4th is the most common way for the 4R70W to die... Sounds like you need a rebuild... or a nice low-mile 98+ transmission.
 
budpytko said:
... the trans. will not shift from 2-3 correctly....
Click to expand...
That is exactly how the trans in my 95 let go. As soon as it tried to shift to third it was like I put it in neutral and hit the gas, it just free revved. Check out greenleafauto.com, you may also want to look at what other trans' will fit in the car (ex: mach 1 auto). Some will need a mod to the wiring harness but that's nothing major.
 
Szlipppp ...


Clutch material is half way gone from the frictions. It's a result of slow clutch apply (thank stock programming and stock valve body config).

You might get some life out of it if you drop the valve body and remove the 2-3 spring along with some plate drilling. The trick is too make it shift with a less effort. Upping the pressure via ECU might help also, but all those are band aid solutions.

If you pull the trans, the clutch packs can be re-done fairly easy. Hovewer, since the trans will be half apart it only makes sense to go thru it all the way, especially at 121k.
 
Ya know, I may have screwed up the problem...Thinking about it, it's the 1-2 shift that it 'slips' on, not the 2-3 shift. Still a clutch pack?
 
Did you ever change out the 1-2 Accumulator to the new design? And when was the pan dropped last?
 
budpytko said:
Ya know, I may have screwed up the problem...Thinking about it, it's the 1-2 shift that it 'slips' on, not the 2-3 shift. Still a clutch pack?
Click to expand...

Yes...the kicker for me was when you said that the problem seems to go away when the car gets warmed up. Basically, the tranny fluid is getting hotter, which makes it thinner, enabling the clutches to grab better. Eventually, the clutches will slowly get worse until it won't grab even when the car is warmed up.

As was stated earlier, time for a rebuild or swap out.

In the meantime, maybe someone can comment on if it is advisable to use friction modifier additive in your tranny as a short term solution.
 
maxmk8 said:
Did you ever change out the 1-2 Accumulator to the new design? And when was the pan dropped last?
Click to expand...

I've never dropped the pan...dealer has done the last two fluid changes..don't think they dropped the pan, just ran thru the flush machine. I doubt if the accumulator has ever been changed. Is that worth a shot? What might I find in the pan that would make me just put the pan back up and go looking for a '98 tranny.
 
Well the reason I am asking is because a faulty 1-2 accumulator can cause all kind of problems. But they usually result in firm shifts. The cost for the parts is around $70 plus about $50 for the fluid and a 2 hrs under the Mark... if it is worth it to you I'd give it a shot but it is hard to say what really needs to be done... without actually experiencing the problem.

121k miles is a good amount of miles for a Pre 98 transmission.
 
If it looks anything like this:

image_874.jpg


then you don't need an answer from us.

Check the 1-2 accumulator. Although a leaking (old design) accumulator won't neutral out like you say that it does. Broken spring will cause a very abrubt shift, not the soft lincoln stuff.

You can check all the seals and accumulators without dropping the pan. Simple trans pressure gauge hooked up to various pressure ports on the trans will tell you a lot.

If I were you, I would get a 5 gallon bucket, undo the bottom fitting at the radiator, slip a piece of hose on the steel line, and route it to the bucket. Then start the car, let the trans pump do its work. When the fluid starts to sputter, turn off the engine immediately. Then let the car sit for 10-15 mins and unbolt the trans pan. You'll have about 1/2 qt. in the pan. Check out the 1-2 accumulator, check for metal shavings and friction material in the pan, and report ! ;)
 
If it makes any difference, it's been doing this for a long time...prob over a year and doen't seem to get any worse. I just lift up my right foot and it shifts, then I remember to kick out the overdrive until it's either warm or I get on the highway when I'm always over 50 MPH.
 
Mad1stGen said:
If it looks anything like this:

image_874.jpg


then you don't need an answer from us.

Check the 1-2 accumulator. Although a leaking (old design) accumulator won't neutral out like you say that it does. Broken spring will cause a very abrubt shift, not the soft lincoln stuff.

You can check all the seals and accumulators without dropping the pan. Simple trans pressure gauge hooked up to various pressure ports on the trans will tell you a lot.

If I were you, I would get a 5 gallon bucket, undo the bottom fitting at the radiator, slip a piece of hose on the steel line, and route it to the bucket. Then start the car, let the trans pump do its work. When the fluid starts to sputter, turn off the engine immediately. Then let the car sit for 10-15 mins and unbolt the trans pan. You'll have about 1/2 qt. in the pan. Check out the 1-2 accumulator, check for metal shavings and friction material in the pan, and report ! ;)
Click to expand...

Sounds good to me...now if the outside air temp will only drop down below mid-high 90's, I'll try this. I do know fluid is nice and red now...fluid was changed about a year ago. I'll add to this when I can get under the car and not roast.
 
BTW, if I do find a good '98 to replace this one with, can the swap be done from under the car? Does the motor have to come out? What? I'll have access to a lift.
 
With access to a lift, knowledge and proper tools, it's a relatively easy task. I had mine taken out, the torque converter replaced and put back in place in 4 hours or so. That was despite some trouble we had accessing the upper starter bolt as well.
 
A lift makes it easy. I assume the place that has the lift also has a trans jack.:)

I did mine in my driveway in the winter. It wasn't bad at all. The propane heater aimed at me helped a lot.:D
 
It takes me 1hr to pull and 1hr to install a trans into a m8, lifted on tall jackstands, with air tools. It's easier than you think.
 
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