Transmission shudder

jch3993

Registered User
I have a question for you transmission gurus. I have a 1994 SC with an automatic. With 90,000 miles on it. For past couple of weeks the trans has started to shudder (not slip). It shudders on light excelleration in 2nd, 3rd, and 4th. So far I haven't been able to get to do it to do it in 1st. If I give it moderate to full throttle it shifts firm with no problems to note. I know of a bulliton from Ford which says to replace all the trans fluid for a transmission shudder. Has anyone experienced this same problem, and if so, did changing the fluid take care of it, or did your trans actually have major problems?
I'ld appreciate all the info I can get. Thanks.
 
i dont have the same tranny in mine but i hear that changing the fluid should solve the problem...Should be done anyways just to be on the safe side
 
Mercon V

If you are experiencing (torque converter) shutter, you should drain and fill with Mercon V. At least that's what I've been told, but then I have an AOD so I don't have any first hand experience that it is effective.
 
just had the same problem i flashed it put Mercon V, and a transmission place but something they called "Blue" in it dont know what it was but it made it better but there is still a little shutter to it
 
I had a somewhat similar problem on a '97 V8 Sport with the 4R70W. Drain the pan and the torque converter. There is a drain plug on the torque converter to help you out. Refill with Mercon V. There should be about 12-13 quarts in there so be prepared for that. For refill I usually add 4 quarts and start it up for a few seconds and shut it down. Then I usually add in 3 quart increments until full. Remember to row through the shift pattern after you add fluid. Don't be scared if the gears don't engage after you've just started to add fluid.
 
Same thing happened a few years ago in my '94 Auto and, at first Ford was going to replace the torque converter. Then they issued a TSB to just flush the fluid. I did this and added Mercon V - never had a problem since except the MV in older models like ours has caused a seal leak between the TC and the trans, so it drips (slow thank goodness) out of the TC access hole. A small price to pay, I guess. If you still have a purely stock 4RW70 then I'd read up on that article on the TCCOA site and if you are going to keep the car - I'd atleast replace the accumulator pistons, MLPS, solenoids and consider adding the '96 valve body, larger sump & filter. I did all this + a Transgo shift kit at 25,000m. Now I have 127,000m with no problems except that small leak.
 
I experienced the same thing recently-changed over to Mercon V, new filter, deep pan with drain plug and threw in a bottle of Trans X to help condition the seals.

FYI-Ford recommends 30k miles between fluid changes when you use Mercon V-something to note when using MV;)
 
Did the TransX work?. I've just put in half a bottle of Lucas seal leak & shift additive to see if I can slow down that seal leak. As for fluid change I've been overcatious since the shudder problem and dump the pan every 15k, then drain the pan, TC & change the filter every 30k. Been good that way for over 100,000m
 
Thanks everyone for your input. Two days ago I went ahead and flushed the trans with new fluid. I also added 32 ounces of Trans-X. It's only been two days but I haven't felt the shudder once since I performed the service. It use to do it every time I drove the car.
 
That's a lot of Trans-X. Let me know how you make out and if it cures the leak. I put a bottle of Lucas in mine (16 ozs I think) and it still has a slow leak.
 
If the lucas didnt stop or at least slow your leak then its one heck of a leak.. That stuff is like sludge. I once put some in a 87 Pontiac 6000 that shifted like garbage. It took me 20 minutes to pour it all in since it was cold out. It fixed it like a miracle, no more dripping and it shifted awesome. It did take a day of driving to cycle it through and have an effect though.
 
There are a few things you need to consider when trying to fix shudder.
First is the condition of the engine a bad spark plug wire, spark plug,coil or even a sticky egr can cause these problems. 94 cars had very poorly designed lockup pistons, most of the 95's had the upgraded one. You should always use merconv fluid in a 4r70w. The 94/95 valvebodies were very restrictive in lockup flow as was the 94/95 case. You can improve the valvebody up to the level that the case become the restriction. Or you can get adapter pins to install a later model valvebody, which in most cases is overkill on an early case. If you need directions on how to do so msg me and I will email you the sheet. I have seen people chase these problems over and over. I have even done it myself. Snake oil or other additives are a waste of time, they temporarily fix it or cause full out slippage that frys the clutch completely. Either seems to take care of the problem but causes bigger problems down the road. It's a good idea to use the 96up style pan and filter on these transmissions as well.
Alan
 
Follow up on shudder

"Thanks everyone for your input. Two days ago I went ahead and flushed the trans with new fluid. I also added 32 ounces of Trans-X. It's only been two days but I haven't felt the shudder once since I performed the service. It use to do it every time I drove the car."


The above is what I wrote on 1/8/06. As I explained the shudder is gone. However, I have learned since then that 32 ounces of Trans-X is too much. The excessive Trans-X caused the oil to thin out. In the morning when the trans was cold, 1st gear would flare before it woud engage. It would do this until it would warm up. I sucked out 2 quarts of trans fluid through the filler tube and replaced them with fresh oil. All is now good. I've been driving the car for 3 weeks with no problems.

I suggest for you guys thinking of flushing the trans, go ahead and do so, but only add 16 ounces of Trans-X if that.
 
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From my experience shudder guard and products like that don't work long. Generally they work by causing excessive slippage thus burning the clutch up even farther.
Alan
 
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