Manual Transmission Fill Plug Stuck

I am changing the MT gear oil (yes using GL4, and I agree with the risks of GL5). I got the drain plug out easily, but the fill plug is not responding to Liquid Wrench and a 1/4 inch impact driver rated to 155 ft-lb. Before doing anything detrimental, I figured that I would ask for some advice here. I will check the shop manual and make sure I'm trying to remove the correct bolt/plug. A photo is attached, if it will load from my phone. It is the only clean bolt, and I know everything is leaking like a sieve. I'm doing the output shaft seal during this.

I haven't had this plug out before, so I don't know what the PO did to make it this hard to remove.

If I can't get it out, has anyone filled the MT from inside the cab by removing the shift boot? I've seen some do it for other trucks on YouTube, but don't want to be the first to try it on this model. This would be a last resort, and I'll wait a couple days before doing anything irriversable.

Thanks,

Chris

You need to fill it through the fill plug. That way you get your quantity correct and can service again in the future. Find a tight socket or box end of a wrench and get an extension on it.

I confirmed that I am wrenching on the correct bolt from a shop manual sketch (attached). I will try a 1/2" drive breaker bar with an extension like Chargerx3 suggested. I want to avoid breaking anything, so that was the main reason I asked.

I found another thread where people take 3 bolts off the shifter and fill from inside the cab. I'm leaning that direction so I don't have to set up a pump from underneath, even if I can get the fill plug out. If someone has another suggestion for easy gear oil installation, I'm all ears.

I also found the torque specs for the fill and drain plug, 35 nm will get them both, but the drain plug can take another 10 nm if I am so inclined. The torque wrench I used to try getting the fill plug out was up around 60 ft-lb.

Thanks,

Chris

Fill by hose from engine bay with funnel on end of hose ~ Filipinos on YouTube method
https://youtu.be/BaE_AwCxe_U?feature=shared

Use a six sided 1/2 drive socket especially if the plug edges are rounded off a bit. Combined with a breaker bar, that should do it.

PIPE WRENCH :hammerdrill:

Thanks @xboxrox, ChargerX2, and FMS88. I got it off with a tight 6 point 3/8" drive breaker bar. It was just about a 1 armed dead lift pulling on the handle, but it went.

Also, the tailshaft seal was a pain. The seal puller helped and I would have never gotten it off without it. https://www.harborfreight.com/slide-...ece-56894.html

Thanks again,

Chris

GOOD JOB Chris

Differentials have them same type drain & fill plugs too & now you know which plug to ALWAYS remove first :thumbup:

If it won't come out. Pull the shifter and fill from the top down. Just measure the quarts
Put a SnapOn box on the plug and hit it with a hammer. Take out any play before you smack it.
Always remove a fill before draining. Live and learn so they say. The rear dif you always want to remove the fill before draining.

Thanks for the words of the wise. Figuring out that I can't get the fill plug out is WAY better before the fluid is all drained. Hopefully that is the last time that I do it that way :grin: