I bought a 2019 f150 with 14,000 miles on it. It's a rebuild. It was an enterprise vehicle that was involved in a wreck. Anyway, I had no problems for about the first 6-7000 miles, then started noticing a shake between 15-25mph. Never could find a problem. Changed plugs, installed a tune, no changes. At about 25,000 miles I crawled under the truck and pulled the trans dipstick out and checked the fluid, it was low. Added just over half a quart to bring it up between the lines. It's still shakes between 15-30mph, any gear. How bad is the damage and how long before my trans exists stage left? I've been told these 10 speed transmissions won't tolerate low fluid operation. I'm guessing I screwed this one.

Thanks in advance for any help.

 

it's probably important to clarify checking the fluid level - what was the trans temp when checked? The LV fluid apparently expands quite a bit, if it was cold and in the low cross hatch area it's probably fine.

if your diagnosis that it's wheel speed dependent and not engine rpm it could be the trans, drive shaft, rear end or the wheels.

 

Weren't some folks having success with the additive to fix Ford trans shudder?

 

10 speeds take ultra low viscosity trans fluid...... hopefully that what was used?

 

I used LV fluid.

The truck was driven for about an hour before jacking up and checking the level.

I'm looking into the friction modifier.

I have doubts it's a driveshaft or rim issue. Those typically don't get better with speed.

 

You heading in the direction of further issues going about it the way your indicating..
The fluid to use is ULV not LV, and checked at the proper temp of 200* +/- 5 on the level, and between the line limits on the dipstick..

 

How does one go about this when the transmission never hits 200F? I'd say I max out at around 180.

 

The transmission fluid you are supposed to use is:

Motorcraft MERCON® ULV Automatic Transmission Fluid XT-12-QULV

what else has been checked? Tire balance, driveshaft?

I wouldn’t add any additives and since you can’t clearly state what temp the tranny was at and added the wrong fluid I’d take it straight to a reputable transmission shop to get the fluid drained and filled properly.

 

Transmission problems almost never manifest themselves as a problem described as a "shake". Don't put additives in your 10r80 trans. It will just further negatively impact the transmission that likely isn't the problem anyway. You already added the wrong fluid at the wrong temp.

Your statement that driveshaft or other problems don't lessen or go away at various speeds is incorrect. In my experience it happens more often than not. I have mud under one of my wheels right now that shakes like crazy at 30-50mph and you can barely tell at 70.

 

Mine is always at around 205°F