Is it possible to change the OD set-up in a 4R100 so that the ratio would be taller ?

For driving around town I would turn the OD off, but for Interstate driving it would be nice to drop the RPMs by 600 or so.

As many have noted here, these motors seem to get their best mileage below 2000 RPMs.

My Lightning is way over 2000 RPM at Interstate speeds.

Thanks for any info...

 

Anything is possible if you have enough time and money. This change would take so much money that it isn't practicle. There are no other gears available, so you would have to design your own and have them made. That's REALLY big bucks!

 

You can always try searching the net for a company that offers an aftermarket OD that will bolt to the rear of your tranny. Try www.klunev.com or Advance Adapters for starters. I bought a brand new bolt on OD unit and shifter assembly from Advance Adapters for $900.00. It bolts to the rear of my t-case in my Jeep. I'm not sure if they offer something for your tranny.

 

Thanks for the intelligent reply, davet.

I have found a few companies that make an overdrive unit that replaces the tailshaft assembly on the 4R100W, but this is way too expensive ($2800 plus installation) and adds weight and another point of failure.

 

B-Man, The 4R70W has a wider gear ratio than the AODE. Maybe there is a similar set of parts for your tranny that would change the final ratios?

My rpms are 2500 @ 70mph but with the 4.6 economy is still bearable.

That's all I got, good luck.

 

I contacted Baumann Engineering and was told that there is no way to change the OD ratio on the 4R100. They said a Gear Venders OD is the only way to go. Baumann Engineering is well known for modifying the 4r70W and E40D/4R100 as well AOD and C4-C6 trannies. Gear Venders is well known in the RV world.
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I contacted www.hermtheoverdriveguy.com who stated he only knows of a divorced type OD to bolt on that costs $2,000.

 

UHHHHHH LIK LETS SAY DRUP DE SPEED DOWN AN DO DE SPUUD LIMTE GOEN FAST GETS YOU NO WHERE ANY QUIKER. BUT HEY I KNOW THATS NO FUN.

 

B-Man, it looks like you'll either have to get taller tires or swap out your ring & pinion gears if you really want to drop the RPMs??

 

Thank you very much for your reply. I was just kinda thinking out loud. Seems like Ford could have made the OD gear a little taller, for those of us who drive on the highway fairly often. Oh well, you wanna play you gotta pay...

5.4MAN -

# 1, I wanted to drop the RPMs when I am traveling the speed limit.

# 2 - Posting in all CAPS is considered rude.

# 3 - If you have nothing of value to add, don't post. I doubt very seriously anyone thinks you are funny, if humor was the intent of your post.


LE PEW -

Thanks for your posting as well. I'm kinda surprised your RPMs are @ 2500 @ 70 MPH. When I had my '01 SuperCrew, it was around 1800 RPMs @ 70 MPH. (I checked it with a GPS as well as the general flow of traffic on the Interstate). Maybe it is because I had the 5.4L ??

Anyway, thanks to you all who posted information. I appreciate your help.

This site is the best !!!

 

I'm kinda surprised your RPMs are @ 2500 @ 70 MPH. When I had my '01 SuperCrew, it was around 1800 RPMs @ 70 MPH. (I checked it with a GPS as well as the general flow of traffic on the Interstate). Maybe it is because I had the 5.4L ??

I think it's probably because of the 4.30 gears with 30 inch tires that the RPMs are so high. I'm guessing you have the 4.10s ...... right? You could probably reduce your RPMs by 500-600 if you go up a couple of inches in tire diameter. But I'm not sure if you can deal with the look of big @$$ tires on your ride.

Good luck.