Can anyone recommend one of the screw onto the oil cap pumps for filling hard to reach housings like transmissions or differentials? The kind that would have the same pump that GoJo hand cleaner would have.

I’ve seen a few and they all look to have the same cheap quality. Not that I care as long as it works and doesn’t make a mess.

this was recommended on another forum, I have not used it: https://www.harborfreight.com/...luid-pump-63588.html

I used this one, it worked but it takes a lot of pumping: Limited-time deal: SMOTIVEPRO 1.05 Quart / 1 Liter Multi-Purpose Oil Pump, Hand Fluid Transfer Pump for Engine, Transmission and Gear Oils, Precision Fluid Dispensing in Tight Spaces https://a.co/d/07DpdQ6x

I have an old Sta lube(?) that came with some gear oil.

The problem is that regardless, oil gets everywhere making things very challenging for a one man operation.

Many vendors have gone to squeeze bag-style one liter containers. Just squeeze in.

I found on Amazon a rubber tube with a fitting that will fit most one-liter bottles. The fitting has a twist lock that controls flow (off/on). I was able to use it on my daughter's CRV rear differential. With the tube attached and locked, I could position the one liter bottle into place without dribble. Once in place, I twisted the fitting and oil flowed. Pretty easy.

Filler tube

I think Harbor Freight sells a small, powered pump. Not sure if it's designed for small volumes though.

After reading reviews the number one complaint on these pumps is that they do not screw onto court size bottles tightly.

The reason is that the harbor freight pump is designed to work on a 28mm-400 bottle cap. Most quart bottles use a 28mm-410 cap. The difference is the 400 thread is 1 turn, the 410 thread is 1.5 turns. They are not compatible that’s why they leak.

Apparently adapters don’t exist, the solution seems to be to purchase a bottle with a 28mm-410 thread cap.

That’s my new lesson for the day.

This looks like a better solution.

https://youtu.be/VbNhswhnvuA?si=pFgY2VXbAY8D_NTH