Mercury Sable 24V Auto Transmission Shudder Low Speed Upshift

[rogerlh]

When driving gently from start shifting seems smooth until 30-35mph when it shifts up to 4th (whatever the last upshift is) when there is a shudder. Feels almost as though it might if there were a few drops of water moisture in the gas. Tranny seems fine cruising at higher speed or downhill and shudder does not happen if driving more aggressively ie positive foot on the gas and moving more rapidly through the gears. It behaves a bit as though when driving a manual, you put it in 3rd or 4th at too low revs/torque but it only does this going shifting up into 4th.

Is this tranny going bad or is it more likely a speed sensor / vacuum problem. I don't sense any slippage going into drive or reverse nor are there any nasty noises. Not certain if I will be looking at a huge bill or not.

[jfl330]

Originally Posted by rogerlh

When driving gently from start shifting seems smooth until 30-35mph when it shifts up to 4th (whatever the last upshift is) when there is a shudder. Feels almost as though it might if there were a few drops of water moisture in the gas. Tranny seems fine cruising at higher speed or downhill and shudder does not happen if driving more aggressively ie positive foot on the gas and moving more rapidly through the gears. It behaves a bit as though when driving a manual, you put it in 3rd or 4th at too low revs/torque but it only does this going shifting up into 4th.

Is this tranny going bad or is it more likely a speed sensor / vacuum problem. I don't sense any slippage going into drive or reverse nor are there any nasty noises. Not certain if I will be looking at a huge bill or not.

I had to put a new trans in our 00' Windstar (yeah extended warranty, only $50!). When we got it back it did something similar to what you described.
We brought it back to the trans shop and they put some kind of additive in the trans and problem has never come back.

[C. Cleve]

Hi, RE, Your sable trans problem, I need some info, What year, How many miles, Any DTC's, Trouble codes? Does it happen cold? Please be specific in your reply.....See Ya, Clay....

[KyooMac]

rogerlh, as little as five drops of engine coolant from a very, very very slow leaking radiator into the transmission oil cooler can have this effect. The fluid will not even have enough contamination to change from the normal red color to pink or would one see any foaming so it may go unnoticed.

[rogerlh]

It is a 98 Sable, 120,000 miles, Check Engine Light has not come on.
Started doing an occasional, brief intermittant cough at stop light.

Had dealer replace a vacuum hose early last year. Beginning to wonder if that may be related. Going to take it to Dealer for computer analysis and see what they say.

[rogerlh]

Had the Transmission fluid and filter replaced week before last.

[rogerlh]

Had the Transmission fluid and filter replaced week before last. Seemed a little bit better and then went back to the

[rogerlh]

Replaced transmission fluid last week. Shudder seemed marginally less but then it started doing an occasional cough/shudder when I stop at a light.

[C. Cleve]

Hi, rogerlh, Time to take the sable into the dealer and have the processor reflashed....Ford TSB# 99-1-4...They will check the calibration to see if your sable needs to have it done....Should be a freebee.....See Ya,....Clay....

[rogerlh]

Thanks for all the feedback. Took it to dealer and he said it is slipping a bit in 4th. I will try getting it reflashed. Just hate the idea of a $2500 bill to have it rebuilt.

[everyman]

I have a 1999 Sable, DHOC, 146K miles.
Shortly after trans fluid change, car began shuddering on light-to-moderate acceleration.

Shudder-Stop fluid additive did not help.

Initially thought it was faulty torque converter clutch, however shudder occurs prior to torque convert lock-up.

Ignition system/plugs/wires are fine; no misfire.

Ideas?

Thanks.

[nicks84]

Might as well ad me to the bandwagon. 99, 110K. Regularyly services on the date. I noticed this around 80 K, and each mo, its gets a lil more noticable. Started with a slow shift thought. Mind you, stuter was not an issue till around 90 K. Again, if I hammer the gas, there are no issues, only at low speeds when Im practially not even accelerating (well, barely), that is cruising at about 1500 - 2k rpms. Its only in between speeds 30 - 40mph. Its slight enought to not to happen is Im goin over 43ish, but if Im going along at like 38, it will almost seem to stay inbetween shifts, or take 3 full seconds to shift, and stutter, and often seems to kick back down, as if its confused wich gear to go into.

Its confusing me (lol). A guy at Midas looked at it and told me that if the flushed and filled the Tranny, it could potentially make it worse, which seemed stranged to me, so I had it done, and sure enough, it seems bit more noticable to me. And, at the moment, its not bad enough to have it rehauled, but will need to be soon Im sure. Anytips ?

[rogerlh]

Long story short. My Tranny eventually died at a light- broken pump shaft. Rebuilt $2400- failed a week or so later - rebuilt again (for free except rental car cost - supposedly pump shaft sheared again) still going. Seems OK except not always smooth changing at lower speeds in stop / go traffic. I suspect some of that is the tranny - has a less than stellar reputation I gather.

[nicks84]

Originally Posted by C. Cleve

Hi, rogerlh, Time to take the sable into the dealer and have the processor reflashed....Ford TSB# 99-1-4...They will check the calibration to see if your sable needs to have it done....Should be a freebee.....See Ya,....Clay....

Out of curiousity, what is this proceedure you have recomended, Im unfamiliar with it (doesnt say a whole lot lol). But maybe it woudl benefit my cause. How much does something like this usually run ?

[everyman]

In the end the problem was the clutch in the torque converter.
The local Ford dealer did an excellent job of diagnosing and replacing the converter, which corrected the problem.

The car runs fine now, mileage improved 3-4mpg on the freeway! I routinely get 30mpg (using Amsoil synthetic).

Previous diagnosic info was from an independent shop.

Strangely, it appears the problems occurs shortly after changing the trans fluid, which is the way it happened to me. (I've used Amsoil trans fluid since 20k, when purchased).

Thanks.