CUCV Transfer Case Fill/Drain Plug Question

[rmesgt]

Hello All... While working on my transmission, I noticed a great deal of transmission fluid on the underside of the truck body where the drive shaft enters the model 208 transfer case. I realized that this is probably due to a failed rear transfer case seal so I replaced it (Item # MPS 9449, $4.94 - O'Reilly auto) and then decided to replace the ATF within the transfer case. I know I need a 30mm socket to remove the drain/fill plugs. Once the transfer case is empty, do you use a thread compound on the drain/fill plugs before you reinstall? I usually use the Blue Monster Tape when working with plumbing components so I have that available. Thoughts anyone???

 

[WWRD99]

Hello All... While working on my transmission, I noticed a great deal of transmission fluid on the underside of the truck body where the drive shaft enters the model 208 transfer case. I realized that this is probably due to a failed rear transfer case seal so I replaced it (Item # MPS 9449, $4.94 - O'Reilly auto) and then decided to replace the ATF within the transfer case. I know I need a 30mm socket to remove the drain/fill plugs. Once the transfer case is empty, do you use a thread compound on the drain/fill plugs before you reinstall? I usually use the Blue Monster Tape when working with plumbing components so I have that available. Thoughts anyone???

You can use a tape on the threads, there can be a aluminum ring for a crush seal that could be there depending if it was lost before or smashed on the drain bolt...I say that because they do fall off into the drain pan and get lost. Check the driveshaft for the inside cap that seals the end of the driveshaft also...sometimes it can leak out that spot...it is like a freeze plug pressed in...I also use a light sand paper with oil like 200 grit to shine up the slide part that goes into the transfer case.

 

[adf5565]

Hello All... While working on my transmission, I noticed a great deal of transmission fluid on the underside of the truck body where the drive shaft enters the model 208 transfer case. I realized that this is probably due to a failed rear transfer case seal so I replaced it (Item # MPS 9449, $4.94 - O'Reilly auto) and then decided to replace the ATF within the transfer case. I know I need a 30mm socket to remove the drain/fill plugs. Once the transfer case is empty, do you use a thread compound on the drain/fill plugs before you reinstall? I usually use the Blue Monster Tape when working with plumbing components so I have that available. Thoughts anyone???

I wouldn’t recommend tape, tried that on the transfer case plug on my 09 Silverado cause there was a slow seep through the threads and it end up splitting the case. Probably a compound would be better.

 

[Skinny]

I think the chain drive cases have a crush washer. I don't remember because both my trucks have real transfer cases. Joking...

That would mean they have straight threads (cut parallel and not it's personal orientation) on the bolt because the washer does the sealing. My 205 had a tapered plug so the threads are interference when tight. I do use thread tape on them.

 

[Tow4]

I've started using teflon tape on oil drain plugs. My M929 had it on all the plugs and no leaks.