Timing of manual transmission oil change (2024)

PBDroadster

Join Date: Nov 2020

Location: Northern Illinois

Posts: 1,541

I did the manual transmission oil exchange today. Out with the OEM oil and in with Ford Motorcraft XTM5QS. The procedure is conceptually easy but the devil is in the details.

First off, it's messy. No matter how careful you are you will get some old and new oil splashed or a bit spilled. I suggest old clothes and placing cardboard strategically under your transmission drain work area and have multiple disposable rags and paper towels to clean up small spills. Working under the car requires configuring and reconfiguring your position so that you have access to the four, 12 mm brace bolts and repositioning to the 24 mm transmission fill and drain bolts. A mechanics creeper is essential instead of wiggling, dragging and squirming around.

I used my Quickjack to get the car up to nearly 23 inches. That is a wonderfully high and comfortable space to work under but it does have some disadvantages. I have a typical 10 quart waste oil sealable container with its recessed catch basin. But at that car height, the basin is too shallow to prevent the oil stream from splashing out. So I emptied the stream of oil into a high sided open oil catch pan and then later transferred it to the sealable container.

The right tools helped the project along.
I have a corded trouble light that gives great illumination under the car.
Getting the car up high with the QJ is a luxury. I have worked in less space but now I'm so much more comfortable with the car up high. I do place four back up jack stands under the lift and two mounted tires laid flat under the wheels of the car, "just in case".
Safety glasses, gloves, rags, paper towels, and cardboard made this project safer and an easy clean up.
I used an impact wrench to remove the four 12 mm brace bolts. And I torqued them back on to 16 ft-lbs.
I used a 24 mm ratcheting wrench to remove the fill plug.
I used the impact wrench and 24 mm socket to remove the drain plug. There is a guard that is forward of the drain plug that limits your positioning of a wrench. And the ratcheting wrench with its fat collar would not fit at all.
The fill plug was replaced and torqued to 38 ft-lbs.
All new aluminum OEM washers were used on the plugs.
The transmission fluid was pumped into the transmission until it dribbled out. There was a sizable amount of left over oil in each bottle that the pump straw could not reach. After using two bottles, I poured the leftover fluid from bottle 1 into bottle 2 and pumped that in. I opened bottle 3 and pumped in until it dribbled out the fill port. Then I poured the remaining leftover oil from bottle 2 into bottle 3.
The fill plug was torqued to 38 with a crow foot attachment on my torque wrench.

The magnetic drain plug had a collection of fine metal dust and tiny fragments on the magnet. When I first saw an image of that years back I thought it meant the transmission gears were failing but have since learned that that finding is expected and normal. The project took several hours because I was first fine tuning my Quickjack lifting geometry, took several breaks, and worked methodically so that I didn't screw something up.

I took the car out for a test drive. The prior shifting feel on OEM oil had become quite good with the exception of some resistance going in reverse. Though occasionally I have felt a slight "catchy" sensation when going from 1st to 2nd or 2nd to 3rd. On my test drive I felt none of that catchy sensation. Reverse was slightly resistant but less so than on OEM. In the end there was a measurable but minor improvement change but not a dramatic difference. I liked doing the project and found it rewarding just to complete it.

Here are some selected photos from the project...

Tools and equipment

Quickjack set up

Location of fill plug

Ratcheting wrench on fill plug

Taking off drain plug

Drain plug debris

Clean drain plug

Oil pan placement

Pumping in oil