Transmission Shudders... Easy Fix?

I experienced severe shudder or wheel hop shortly after buying my car. The previous owner never had the trans fluid changed so I went ahead and had a flush and filter done at 79,000 miles. Well less than a 1,000 miles later i started experiencing what I called wheel hop when trying to accelerate from a stop and merge into traffic (moderate to heavy acceleration).
Brought it to the local dealer and explained that it was trans shudder and they wanted to change out the high and low pressure solenoids in the trans even though they were ohming out Good. And they would not guarantee that that would fix the problem for $750.00.
So I looked up and old friend who works at an aftermarket trans rebuilding shop about 100 miles away from me and explained the problem and he agreed on the high pressure solenoid but also explained what the real problem was.
The trans fluid was getting around the plunger on the end of the solenoid that controls the fluid due to scoring or wear in the bore where this plunger fits in the valve body. The flush had removed varnish and gunk that was keeping it sealed up. Anyway the high pressure fluid leaks past this solenoid plunger and the trans commands high then low, high-low, high-low pressure in rapid succession causing the shudder and wheel hop.
The fix is to gain access to the valve body, bore and hone the hole, install a sleeve and install a new solenoid due to all the exercise it was getting.
The dealer can't do that kind of repair they could only replace the whole valve body yet they never mentioned that to me. So I drove it down and left it for a couple of days and $600.00 later my shudder and wheel hop went away.
But the flushing would prove to rear it's ugly head again several thousand miles later with various shift issues and TCC sticking problems so that's when I authorized a complete teardown and rebuild with under 100,000 miles on the transmission. But all is well now.
The End.

Thanks for the info.
I have heard lots of horror stories about trans. flushes.

Bert

Flushes are good if you do them regularly, like every 30,000 miles depending how you drive. When i had access to a flushing machine I would do my truck once a year (15,000mi.)

Rickw wrote:

Flushes are good if you do them regularly, like every 30,000 miles depending how you drive. When i had access to a flushing machine I would do my truck once a year (15,000mi.)

No offense but the traditional filter/fluid change would be less of a gamble in my opinion.
Too many variables introduced in the flushing process. For instance: the possibility of trash coming from the flush rig into the trans. being flushed or incorrect flush machine operation because of user error.

Bert

I too have heard of too many issues caused by trans flushes. But guess what. I bought my car with 48000 miles and right after my first fluid/filter change, I had shudder. I let it go too long and wiped out the first gear clutches before I took it somewhere to be fixed, and was down for a whole rebuild. The only time an aftermarket used car warranty has ever paid off for me!! Worth every penny of that one!!

Yeah, I only had to pay a couple hundred out of pocket for my trans rebuild. Unfortunately I had to pay for the two bad trans mounts @ $600.00 for both. (not covered items)
That was before I knew about this site obviously, otherwise things would have been done a lot differently. I'd have a performance trans instead of a regular rebuild and i would have kept the old mounts and tried the polyurethane tip.

lately i have noticed that if i give my car light acceleration from a stop the tranny will shudder a little bit. this only happens once and a while though im confused.

My problem started as occasional and progressed to every time I needed to accelerate into traffic, almost was rear ended a couple of times before I had it fixed.
I was told by the rebuilder that this is a common problem on these transmissions and there is a Kit available to the aftermarket rebuilders to do the mod / repair.

so there is no way to get around spending boatloads of cash to fix this......that sucks. my car might go up for sale then.

This guy was pricey. Labor rate was $85.00/hr.
If you search around to various trans shops, discuss the problem and possible solution with them, you might get it done cheaper.
Print out what i wrote and see if any of them agree or know about the sleeving of the high pressure port. make sure they have a clue and let them know you have a clue, it could save you some money. I made the mistake of telling them that the dealer wanted $750.00 so they did me a favor for $600.00. i probably could have got it done cheaper if I shopped around.
Remember this guy was an old friend that used to do transmissions for a GM dealership and now has his own shop and needs to pay the bills, so friendship means nothing. Once he had the car I just let him fix it cause he knew what the problem was and the local dealer was giving me the run around.
Good Luck

is there any chance that it is not your problem....just tryin to be optimistic

Yeh, there's always the possibility it's something else. I was just sharing my only experience with that particular problem.
If you bring it somewhere to be checked i would think a diagnosis wouldn't cost you anything. Then you can get an idea of what they think the problem is and a price to fix it.
Bring it to a few shops and compare.

ok thx a lot for the input rick

What you need most likely is a new pressure control solenoid. I found that pulling my car into 1st on the selector hid the problem unless it was really hot. I found my car only did it when it was hot (at first - eventually it happened all the time)

Unfortunately you have to open the case to put in the solenoid. Shop around, many shops should be familiar with it.

Mike, how many miles are on your car? How new are your spark plugs?

I'm having a similar shuttering problem with my transmission, usually occurs when pulling out of a parking spot in a parking lot and very slight...I am fortunate to know some good transmission people and they all share the same opinion when it comes to a power flush, it dislodges all the crap and sends it into the small filters and plungers within the valve body where it usually stay's until it starts causing noticable problems like shutter and wierd shift patterns. I don't believe they'll say it always happens or it leads to major melt downs but the regular transmission fluid filter changes seem to be the preferred method of preventive maintenance.

there are 101000 miles and plugs were changed about 1000 miles ago. is it possible for them to be one to be fouled already

so i figured out that it cant be a problem with the tranny for this one reason, there is only one location that it will shudder without fail no matter what and no where else. There must be either a lot of ice there or a big crack or something.

good...transmissions are expensive, it is very possible to get a bad plug right out of the box and more possible a damaged boot while pulling it off the plugs to be changed. I once even knocked the gap off on a new plug while installing, rushing to finish the job...dumb move on my part. check that all the plug electrodes are tight too they can loosen up from screwing the plug in and then become a problem when some moisture is introduced.

I would think any of those would throw a code - have you used more than one reader to check? I'm throwing code P0341 and have similar shudder - this code is the camshaft position sensor but also stated a possible wiring, plug or coil pack problem. I had mine read at Autozone but plan to take it to other places to verify...good luck!

nope no codes, just that one single spot in the road.

I just picked my 97 Supercharged Riv and under wot the transmission shudders between shifts. I was thinking that i might be able to have my friend with a tuner bump up the trans line pressures and work the shift maps a little bit to smooth it out. Im gonna change the filter and add a bottle of lucas in there.

Is this a common problem? Could it be a solenoid or sumthing that can be repaird/replaced without droppin the trans or to much trouble?

With fords/Lincolns the first thing suggested is to change the transmission fluid. If it persists after that, then it's usually a main-control valve. These transmission are totally different however. This concern is very common for Town Cars, but those are rear-wheel-drive.

Unfortunately these transmissions are known weak areas. The Pressure Control Solenoid (and TCCS) is very sensitive to being dirty. Unfortunately the trans has to be dropped to replace the solenoid. Some have said that getting a GM dealer with a Tech-II to actuate the solenoid back and forth has freed it up.

The Torque Converter Clutch solenoid could be stuck too - do you notice your torque converter unlocking if you are cruising and step on the brake? Does it pull or shudder while you are sitting at a stop? That could indicate a stuck TCCS.

At any rate, fresh fluid is a good place to start.

Easy fix? Maybe. Change the spark plugs & ignition wires before you go monkeying with the transmission.

Yes, this is a common problem, especially if the car has over 100k miles. DON'T put that Lucas Oil in there until you are sure it is a transaxle issue. Even then, I'd be hesitant!

NAPA sells some stuff called "Shudder Stop" I think the company that makes it is named Dr. Trans. You should be able to google it and find it...

My 95PA was shuddering just slightly when it shifted into/out of OD.

If yours is doing it between every gear I doubt it will solve the problem but it took care of the PA problem.

I would do a AA says... a miss in the engine can be misdiagnosed as a trans. problem.

Good Luck

Bert