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winnie32v's avatar
winnie32v
Explorer
Mar 22, 2014

Ford 4R100 Transmission Question/Problem/Advice

I have a 2001 Winnebago Adventurer 32V built on a 2000 Ford F53 Chassis with a V-10 and 4R100 Transmission.
It has 45,000 miles on the unit.
I bought this motorhome about 2 years ago at 41,000 mi.
I changed all fluids.
I drained the 4R100 torque converter and dropped the pan and replaced all of the fluid with new Dex/Merc transmission fluid.

This year while returning from Florida to Pa. I noticed a "transmission shudder" when the transmission downshifted to 3rd at approx 3,000 RPM.
When the "rumble strip chatter" started, I would just let off of the gas about 1/8" and the chatter would go away.....when I gave it a little more gas, the chatter resumed.
Sounds like the transmission clutches.

When the unit downshifted to the next lower gear...at appx 4000 RPM, there was no chatter.

NOW, I have found out that the 'Dual Purpose' Dex/Merc is NOT supposed to be used to replace the original Mercon transmission fluid.
SO........I have also found out that the "Old" Mercon original fluid can be replaced with the better synthetic Mercon V oil.

My task this summer is to drain the torque converter (yes, this year has the drain plug), the pan AND gently blow out the cooler tube (15 psi) and replace the better fluid with Mercon V fluid.

So a couple of questions:
1. Did I do any possible damage to the transmission using the Dex/Merc fluid?
2. From anyone's experience, will the Mercon V cure the clutch shudder problem?

Also, I should add that I went from a 2000 Jeep Wrangler soft top as a tow vehicle to a 2008 Jeep Grand Cherokee....maybe an additional 1500 - 2000 lbs tow.
I DID notice the extra weight when I was going up the hills.
This probably amplified the transmission issue and brought it to my attention !!!!!!

The engine runs great and everything else is running fine.

Please advise from your experience with the 4R100 transmission and let me know if I'm doing the right things to get me back to Florida this winter.....OR....anything else that might refer to this situation.

Thank you for your time and advice.
Regards,
Paul

6 Replies

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  • John_Wayne's avatar
    John_Wayne
    Explorer II
    Mar 22, 2014
    Used CloudDrivers method to flush trans fluid twice so far and just turned 113,000 miles. Also installed on mine a Banks transcommand and an external trans fluid filter in the return line from the cooler. Same one Ford calls for if you ever install a rebuilt trans. Magne fine NAPA# 1-8514.
  • Gdetrailer's avatar
    Gdetrailer
    Explorer III
    Mar 22, 2014
    Have you ever had your drive shaft slip joint serviced?

    If not, you might want to consider dropping the drive shaft and pulling the slip joint apart and regreasing it.. It is a common issue which allows the drive shaft to chatter under load when the grease has dried up. There is a special grease which Ford uses to address this problem..
  • CloudDriver's avatar
    CloudDriver
    Explorer
    Mar 22, 2014
    I have changed the fluid in our 4R100 transmission twice using this procedure, once at 30,000 miles and again at 60,000 miles. Now have 82,000 miles and no tranny issues. First change was with Mercon and second was with Mercon V as the original Mercon is no longer available.

    Easy job in the driveway.
  • George_H's avatar
    George_H
    Explorer
    Mar 22, 2014
    On the advice of transmission service, who also owns 7.3 PSD and 4R100, I use Amsoil in mine. Have multiple crossings of Continental Divide with no issues.
  • 301TBS's avatar
    301TBS
    Explorer
    Mar 22, 2014
    The shudder should go away with the fluid replacement. You are doing the right thing by draining the torque converter and dropping the pan to check for debris.
    The shudder is usually caused by the torque converter clutch. I have seen this happen with as low as 50,000km on original fluid. Most often fresh fluid and a couple of weeks of driving will clear it up.
    I'm not up on the proper fluid to use anymore, but a good Ford dealer should be able to tell you.
    Good luck.
  • westend's avatar
    westend
    Explorer
    Mar 22, 2014
    Paul,
    From my experience, the 4R100 is a pretty reliable tranny. I can understand your confusion about the correct fluid, the last time I bought some Mercon from Ford, they seemed to be somewhat confused, too.

    I think you'll be all right with a complete fluid change as your tranny seems to be at least working. It may be that the Dex/Merc has allowed some build up in a valve seat or has caused a sticking valve. The new fluid with it's additives should clear it up. If not, you might want to try some tranny additive but I would hold off for a number of miles for the new fluid to work.

    I've forgotten exactly how the strainer is in that tranny. IIRC, Ford says not to replace it under normal conditions. You may want to shoot some solvent up into it and blow it out when you have the pan removed. Then again, you're Ford's customer and they should be willing to give you some advice on the filter and the procedures you're using.

    I know you can run the fluid out of the tranny by removing one of the coolant lines and running the engine but don't use that procedure for mine. There are videos out there that show how to do it. What I do with mine is drain the pan about every 6-8 or so oil changes and add back in new fluid. I aim at a 25K mi interval but don't always hit the bullseye. This replaces about half of the tranny fluid. I figure by the fourth time I did it, I had pretty well replaced the old fluid by dilution and the transmission sees new oil at that closer 25K service interval.

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