RMguy

I'm buying the USShift controller asap.

All the aftermarket controller manuals I've read say to swap out the force motor in early 91-93 4L80E's for the newer black unit.

Since I do have a 1991 4L80e I need to know if it's truly safe to run the newer style force motor?

Some say the new force motor CAN NOT be used in the early 4L80e's and that it could cause pressure issues and a blown trans.


.

jimmyg

You have to switch to the newer black holley epc soliniod it's the silver Bosch one you can't use. Def go with us shift I love mine the part # is on the U.S. shift site

RMguy

Thanks. Have you actually used the newer black force motor long term in a '91-93 trans with success? How many miles do you have on it?

jimmyg

Not long term . But I'm pretty sure everybody updates them when the rebuild them.. Can anyone chime in on this?

jimmyg

They have a new one out called the quick 4 I just sent mine in to get updated

forcd ind

iTrader: (7)

I think you need the newer wiring harness also, around 93/94 they changed it over-yours may already be changed if any work was done to it
(diff case plug)

RMguy

Thanks. I've got everything figured out except the force motor.

Hopefully some transmission experts chimes in (what happened to Jake?). If not I'll call around to some shops on Monday and see what they say.

I'm not sure if GM even makes the old style force motor still.

jimmyg

Just email jake .

clinebarger

From ATRA Bulletin #264.
The second design force motor (Black Holley) will work on all models. The first design force motor should not be used on vehicles designed for the second design. For this reason, always use the second design.

jakeshoe

iTrader: (14)

I no longer answer tech questions online unless it's a customer, and then I still prefer to communicate via email or phone.

I used to pay to be a sponsor here, and in doing so, I was paying to attract the traffic to this section. With a considerable backlog at the shop, it doesn't make sense for me to pay to advertise, especially when it benefits the forum more than my business.

I was one of the few professional transmission builders helping the general enthusiast online, to the point it was expected not appreciated. Other businesses who have never helped online seem to be popular for whatever reason.
I have tens of thousands of posts online helping the enthusiast with trans tech. Most of that info is still valid.
I learned what I know by earning it, oftentimes the hard way. It's not unreasonable to let others earn their knowledge the same way.

I also learned that most guys will listen to the "internet consensus" which is most often incorrect, or they will listen to the answer they want to hear. It's not worth my time and effort to try to correct the misinformation.

As for your EPC. There's more to it than just swapping it out.

RMguy

No problem. I'll give a call on Monday about the EPC and to get a price on the USShift box.

forcd ind

iTrader: (7)

The ATSG man. talks about the change, besides updating the force motor the sep. plate gets addressed and also the TSC valve
All the controllers use the updated case plug, so you need to look at that