1999 SHO Transmission Shudder

[alleycat]

I have a intermitant shudder in my transmission at about 30 mph when I accellerate slowly. It seems to be getting worse. Any ideas as what it might be.
I just got new tires and an alignment but it feels like it is in the transmission or drive train.

 

[SHOtimer]

Change the tranny fluid and it might help you out a bit. But, your tranny is on the short road to a rebuild.

Doug

 

[alleycat]

1999 SHO ransmission Shudder

thanks, I'll start with that.

 

[SHO#7]

Try not letting it go into 4th gear. I just put it in drive, instead of overdrive. I felt similar issues when I had a coil going south. Only came in when the TC locked up under light load.

 

[ShO_oFF97]

Transmission Shudder

I had a transmission shudder since i bought my SHO 3 months ago.. everyone told me it is normal with these cars they have a very fine gear... well i dont agree with them... my transmission just went out i have no forward gears anymore. there is also a whining sound(sounds like power steering pump goin out) but it comes from the driver side and maybe down by the tranny... anyone know what it is?

 

[SHO#7]

Sounds like you are in need of an overhaul. Hope that everyone who told you that shudder is normal, also explained that it is normal to spend over 2500 to get them rebuilt correctly.

Good luck.

 

[MilTownSHO]

there is also a whining sound(sounds like power steering pump goin out) but it comes from the driver side and maybe down by the tranny... anyone know what it is?

VERY common before failure!

 

[2 4shofast]

VERY common before failure!

Thats exactly what happen to mine last month. It started to whine and then stopped engaging. Sorry to be the bearer of bad news but......A SHO is a SHO...

 

[CT97White]

My 97 started to shudder in 1st gear only last Friday night with about 88kmi on the car. It quickly progressed into 1st gear slipping at anything more than light throttle.

Given that my problem is only in 1st gear, I think it is the low one-way clutch that has gone South since this is the only clutch that is only used in 1st gear. The car went in the shop today & the new transmission was order this afternoon. I should have it back on Thursday with a Ford reman transmission with a 3 year/36 kmi warranty for $2600 installed.

 

[ShO_oFF97]

Transmission Shudder

yeah my car is in the shop right now getting an overhaul. when i bought the car i also bought an extended warantee so i made a good choice there cuz the shop i took it to said $2200 with shift kit and good cooler... so i dont pay anything!!!

 

[ShO_oFF97]

i got my tranny done finally and wow its so much better now haha, much better acceleration

 

[93SHO'nOFF]

I have a intermitant shudder in my transmission at about 30 mph when I accellerate slowly.

What you are actually feeling is the torque converter clutch slipping when it is going into lock up,(Torque Coverter locks up to help cool the trans and to improve fuel economy/locks only in O/D)When the fluid starts breaking down it looses it's friction capability so the clutch starts slipping against TC hub while it engauges(feels like driving over rumble strips)Get you transaxle flushed out and new mercon fluid.99% of the time thats the fix,but there is a small chance the Torque Converter needs replacement only if the flush didn't seem to change the way it feels.Trans flush should be done every 30K.
Later

 

[Ian Macoomb]

Actually the TC also locks in 3rd gear also.

 

[93SHO'nOFF]

My Bad,
I'd like to retract my last statement to make it politicaly correct.
The TCC is actually applied in 2nd,3rd,& 4th gears.Shudder is noticed mostly on a light accell only in O/D gear range between 30/40mph.If the transaxle is in any other gear range the TCC is comanded OFF by the PCM.
But who's trying to split atom's here.
Thanks!!
Ian Macoomb for pointing out the discrepancy in the last post
Your my new hero!
Later :evil_gri:

 

[Ian Macoomb]

I'm not sure that it locks in 2nd gear. I think it's just 3rd and OD.

 

[93SHO'nOFF]

Yeah,I'm positive it does.In fact I went ahead and dug up a copy of TCC operation from the AX4N/AX4S Ford Referance manual just for you to help clear any other questions you might you have.
Pay close attention to the part in BOLD I highlighted
If I can find a Solenoid Application chart I'll make a copy and post it also.
THEORY ————————————
ELECTRONIC COMPONENTS
Torque Converter Clutch Solenoid
Description:
The Torque Converter Clutch (TCC) solenoid is an electro-hydraulic actuator that varies hydraulic pressure and is operated by electronic Pulse-Width Modulation (PWM) control.Taurus/Sable vehicles use a TCC solenoid wiith OFF/ON control strategy.
The PCM varies the pressure in the S4 hydraulic circuit to position the bypass clutch control valve. Bypass clutch control valve position determines whether TCC is fully applied, fully released or operating under controlled modulation. Taurus/Sable vehicles use TCC that is fully applied (ON) or fully released (OFF).
See page 52 for more information about the hydraulic circuit operation of the TCC solenoid.
CAUTION: Use of a PWM-type TCC solenoid in a Taurus/Sable vehicle may damage the PCM.
Symptoms:
If the TCC solenoid fails ON, the engine runs rough and may stall at low speeds (2nd, 3rd or 4th gear). Also, vehicle shudder may result.
If the TCC solenoid fails OFF, poor fuel economy may occur. TCC will not be applied.

Any Questions?????????

 

[SHOZ123]

My Helm DVD also says that the TCC may be engaged in 2nd gear. Although I have never felt it. May not be true on the SHOs (just a guess).

 

[Axianator]

Ian is correct on this one.

FYI, here are some notes about the converter strategy on the SHO:

- lock-up via the converter clutch is achieved electrically via a solenoid in the valve body
- all manner of converter behavior (lock, unlock, clutch slip, etc.) is controlled solely by the EEC
- lock/unlock behavior itself is governed first by throttle position, followed by speed
- the lock function of the converter is only used in 3rd and 4th gears (the converter remains unlocked in 1st and 2nd)

Note - the above points apply to both the Gen 2 and Gen 3 ATX's.

 

[93SHO'nOFF]

Ian and Adam,
Well the answer to this is that I have scaned a few pages from the Ford AX4S/AX4N Automatic Transaxle Referance Manual.This shows mech/hydr and electrical theory and operation in Depth for those transaxles.The Service Manual and QCdealer web site all show the same results that TCC can apply in 2nd,3rd,& 4th gears.But I can't seem to get Pic's to post on here?
For those that don't believe send me your email address and i can send them to you in a attachment.
Then some can update their notes correctly
Later
Mike

 

[SHOZ123]

Torque Converter Clutch (TCC) Solenoid 7G136:
is used in the transaxle control system to control the application, modulation and release of the torque converter clutch.
Symptoms:
Failed ON—engine runs rough/vehicle shudder, engine stalls in DRIVE at low idle speeds (2nd, 3rd, or 4th gear).
Failed OFF—torque converter never engages.

DTCs: P0741 ** , P0743 * , P1741 ** , P1742 ** , P1743 ** , P1744 ** , P1767